A recent post on Horse Trails and Camping Across America about fuel mileage for trucks towing trailers, showed that a lot of folks are concerned about this and are looking for ways to save on fuel by adding after-market add-ons and accessories. I have a lot of these on my truck, so I thought I’d make a post about them, so that folks who are considering them might have a little real-life information to help them evaluate. I am open to PMs for anyone with questions through my facebook page.

My truck is a 2005 Dodge 3500 dually, 5.9L Cummins Diesel, NV5600 6-speed standard transmission, 4-wheel drive, 373 diffs. I bought it used in 2009 with 208,000 miles on it. It was in very good condition and was apparently used by a medical corporation for hauling a trailer around to various disaster locations (that’s my best guess, from various hints I found in the documentation).

Normally I would never consider buying a vehicle with over 100,000 miles on it, but diesels are a little different in this regard. Diesel trucks used for long-hauling, that have had regular maintenance, regularly survive in good condition well up into several hundreds of thousands of miles. This bodes well for those considering buying a used truck, because, as in the case of my truck, people have a tough time selling a truck with over 200,000 miles on it, regardless of its condition, and if you shop around and know what you are looking for, you can do very well.

Before I began to look for a truck, I went to my Nephew, Aaron LeSueur, owner of LeSueur Advance Automotive, 255 North Main Street, Eagar, Arizona, who is one of the best auto mechanics in the state of Arizona. I asked him what I should look for in a diesel truck. After going over the various makes and models, he said this: “If I were going to buy a diesel truck and could pick whatever I wanted, I’d look for a 2005 Dodge with the 5.9 liter Cummins.” His justification was his personal experience with servicing diesel trucks over the past 10 years or so. In his opinion, the Cummins diesel engine has been around longer than the current offerings of all the major truck makers, and the 2005 was, in his opinion, the best year for that engine, before the federal government began increasing the air-polution equipment requirements on diesels. His second choice, as for an engine, was the Ford 7.3 diesel, which has been out of production since about 2001. He said the later Ford engines have been going through a lot of development problems, and to stay away from them until Ford gets things squared away (I’m told the offerings later than 2007 are much better).

So, with that in mind, I began looking for a 2005 Dodge 2500 (3/4 ton) or 3500 SRW (1-ton, single rear wheel) pickup. My other requirements were four-wheel drive, and standard transmission. The need, or desire, for four-wheel drive is pretty obvious, but many ask, “Why a standard transmission?”  First, I have been raised on standard transmissions. I like shifting gears. I guess it just feels “like a man’s truck” to me. I have to admit that driving an automatic in traffic is much more comfortable, but there is no question that a standard transmission will last longer with fewer problems than any automatic transmission ever invented. As I started looking for a truck I found that any advertisement for a truck with an automatic transmission invariably had some statement attached to it to the effect of, “Trans shifts well”, or “fresh trans,” or “low mileage on new  trans”, all of which indicate there is a problem with durability in automatic transmissions. When a truck has a standard transmission, it is rare to see any comment other than the fact that it has one.

My truck, like I said, had 208,000 miles on it when I came across it on eBay. It was at a dealership in North Carolina. Other than the dual rear wheels, it was exactly what I was looking for. It was advertised for $18,500, which was several thousand less than other trucks I had been pricing with single rear wheels, plus, this one was within driving distance, saving me about $1,000 in shipping cost.  Interestingly, I found that out here in the east (I currently live in Virginia), where traffic tends to be high, people like automatic transmissions. Out west, where hauling might mean miles of open road, people seem to like standard transmissions. This particular dealer was having trouble unloading this truck with a standard NV5600 6-speed transmission and over 200,000 miles on it, out here in the eastern US.

After doing a little research, I discovered that the fuel mileage penalty for dual rear wheels is only about 1-2 miles per gallon, but that if one is planning to haul a heavy trailer, the extra stability offered by the dual rear wheels is substantial. As it was, reports from various forums I participated in agreed that the fuel mileage to be expected from a 2005 Dodge 3500 with the standard transmission and 5.9L Cummins diesel, was in the area of 17-22mpg (no-load, highway). This was the same as the official mpg rating on my 2000 Toyota Tacoma with a 4-cylinder gas engine and standard 5-speed transmission! I decided to take a look at this one.

I contacted the dealer and made a tentative deal at $17,500. My inspection went well and I found the truck to be in exceptionally good condition, despite the mileage. The only obvious wear I could find was in the leather of the driver’s seat, on the left side where one gets in and out of the truck. I bought the truck for cash and ended up walking out with a total, including dealer fees, of $18,400, which was still well-below the asking prices of similar trucks I had been seeing in far poorer condition, both at dealers and from private individuals.

These are the accessories that either came with the truck or I have added since I bought it:

Bully Dog Outlook monitor/Triple Dog combo (v 2.4.3)
AEM Brute Force air intake
4″ exhaust (catalytic converter only, no muffler)
2″ leveling lift in front
Bilstein shocks (blue/yellow)
Buckstop Baja front bumper
PIAA driving and fog lamps
235/80-R17E Nitto Terra Grappler tires
Dynatrac ball joints
EMS Spyn-Tec Free-Spin hubs,
One-piece custom 5″ aluminum driveshaft

As I start talking about the accessories, let me set the proper tone with a short preamble here. Many of the listed accessories were on the truck when I got it. Others I added when I had to replace worn original parts, allowing me to leverage the upgrade cost against the replacement cost of the dealer part. Not only that, but I plan to have this truck the rest of my life. Barring an unforeseen catastrophe, I will never own another truck. Let it be clearly understood. There is no performance accessory made that will increase your fuel mileage enough to pay for itself over the time span the average owner will keep his/her truck. Also, you can not add up the various fuel mileage savings attributed to each individual component. The increased efficiency attributable to individual components simply becomes part of the whole system. In other words, if a manufacturer of one accessory component, such as a computer chip, says it will increase your fuel mileage by 5 mpg, and the manufacturer of an air intake system says you can save 5 mpg with their system, do not expect to get an extra 10 mpg by adding those two components to your truck. Trucks that have been modified for high performance, such as larger turbos, or dual turbos, will often benefit more from some of these add-ons than stock trucks. Having made myself clear on these points, I have to admit that I love adding accessories to my truck. I think it’s a natural thing. Just don’t deceive yourself by justifying the purchases based on fuel savings (unless that’s the only way you can get it approved by the spouse!)

Another point I think is relevant here, since we are trying to evaluate things that may increase fuel mileage, is that things such as tire size affect not only real fuel mileage, but also calculated fuel mileage. If you use wheels and tires that are not standard size, as stated by the truck manufacturer in the manual, your speedometer and odometer will be inaccurate, and will affect the accuracy of your fuel mileage hand calculations. Simply stated, if you put larger than stock tires on your truck, your speedometer will indicate that you are traveling slower than you are actually going (and cops and judges aren’t very sympathetic on that issue), and your odometer will understate your miles traveled. Therefore, your fuel mileage hand calculations will show fewer miles per gallon than you are actually getting. On the other hand, if you put smaller tires on your truck, you may be unjustifiably happy about your fuel mileage. On newer trucks, the truck’s computer can be programmed to adjust for non-standard size tires. Some after-market chip manufacturers also provide this capability. Using GPS to figure your distance mileage can overcome tire-size inaccuracy as well.

To add to the above, the factory installed digital fuel meters, which supposedly tell you your fuel mileage either cumulatively or up-to-the-minute, are notorious for overstating actual fuel mileage, particularly when you are babying the fuel pedal to increase your mileage. In my truck, I have babied the meter up as high as 23mpg in town/rural driving, while my actual hand-calculated mileage was in the area of 17mpg. Folks on truck forums jokingly call them the “lie-o-meter”. Vehicle manufacturers increase their vehicle sales by claiming increased fuel efficiency in their vehicles. That’s what everybody wants – better fuel economy – even in trucks, so it’s understandable that they would set their fuel meters to be, shall we say, optimistic. In normal driving, my meter normally shows about 19mpg, while my hand-calculated mileage hovers between 14 and 15 (town/rural driving).

Finally, before I begin the taste tests, I should mention that if you are contemplating buying a dual-wheeled (DRW) tow vehicle for your horse trailer, do not even consider one without four-wheel-drive. The dual wheels of the rear spread the vehicle’s weight over so much area, that there is actually very little weight on the rear tires individually, which results in reduced traction. A two-wheel-drive DRW vehicle will leave you stuck in the most aggravating circumstances. My pickup, even with the aggressively treaded mud/snow tires I use on it, will get stuck on level wet grass in two-wheel-drive if I have no load in it. It would be quite embarrassing to have someone in their family minivan pulling your truck out of a little old patch of mud somewhere! However, in four-wheel-drive, I can go just about anywhere. Again, if you plan on hauling a horse trailer around, do not consider a two-wheel-drive DRW truck. The fuel mileage penalty for four-wheel-drive is only about 1-2mpg, and in the Dodge trucks, that loss can be reduced to be comparable with a two-wheel-drive truck, as I will explain later.

The Chip

First, I’ll talk about the chip. Ever since computers entered the engine management scene a few years back, folks have been trying to circumvent the factory programming restrictions (to comply with government environmental regulations) to improve torque, horsepower, and fuel mileage. Since horsepower is the product of torque and RPM, and since diesel engines are low RPM engines, torque is the most important factor here. Chips reprogram the timing sequences of the diesel fuel injection system, to maximize power output of the engine. The increased torque (and therefore horsepower) increases fuel mileage simply because a more powerful engine pulls a load easier than a weaker engine, requiring less “foot” on the fuel pedal. Claims of huge fuel savings from chip manufactures have fallen far short of reality. To expect more than an increase of about 2-3 miles per gallon is unrealistic. Many people actually experience a drop in their fuel mileage after installing a chip, however this may properly be blamed on the “fun factor” of having increased horsepower. It’s so much fun to stomp the pedal once in a while and watch that black smoke billow as the rear wheels spin! It’s tough to resist feeling the power sometimes.

Which brings us to another matter. Government regulation in the computer programming was occasioned by the fact that fuel injection can be timed to eliminate the black smoke problem that diesels have when too much fuel is dumped into the cylinder and cannot all be burned during ignition. However, if not enough fuel is dumped in, you lose power. The chip changes the programming to dump more fuel in a timing sequence that produces more power…and lots of black smoke. I found that with my Bully Dog chip set on a the most aggressive aftermarket program available for it, aptly named “Crazy Larry” after the programmer, I loved the power, which allowed me to easily spin the dual rear wheels on dry pavement even in fourth gear, but the amount of black smoke dumped on the gasping public was embarrassing. I have reset it to a more reasonable power level, which is a good compromise between black smoke and towing power. It increased my fuel mileage at most about 2mpg over the standard programming from the dealer for highway driving.

If you are considering a chip, here are some things you should know:

First, if you have an automatic transmission, the added torque will damage your transmission eventually. There is no question about it. You cannot avoid it by driving carefully. It will damage your transmission. If you decide you still want to chip your truck, you should consider having your transmission upgraded as well. There are modifications that can be done at a reasonable cost that will extend the life or your automatic transmission. There are also after-market transmissions that are built specifically for trucks with increased towing capacity and power. Neither of these options are a good investment, money-wise, unless you plan to have your truck for a very long time. If you have a standard transmission, you are safe as far as the transmission is concerned, however the more aggressive programs can overpower the clutch, causing it to slip and fail prematurely. There are aftermarket clutches that will remedy this problem, however in this regard, driving carefully is an alternative.

Secondly, if you chip your truck while it is under warranty, your warranty will be voided and will not be honored for any reason by the dealer. There is no way to conceal the installation of a chip from the dealer. Even if you remove it completely, they will see the tracks of the programming when they do their analysis. If you buy a truck that has had a chip installed, do not expect the dealer to honor the warranty.

Thirdly, if you chip your truck and take it in to a dealer for any kind of engine or drivetrain service, the dealer will, as a matter of course, reset your truck to its factory programming, unless you specifically tell them not to do so. If that happens, you will have to reprogram your truck after the service.

Fourthly, most chip programmers are “VIN-locked” (VIN = Vehicle Identification Number) to the vehicle on which the chip is installed. This protects the manufacturer’s interests, such that a person can’t use his programmer to program his friend’s truck. So if you buy a truck with a chip already installed, make sure you also get the programmer from the seller! In my case, I did not get the programmer (the dealer never received it from the original owner). When I started having trouble with the chip (which was reset to factory by the dealer), I could not re-program it. I found a programmer on eBay that was VIN-locked. I bought it and was lucky enough that the manufacturer, Bully Dog, looked sympathetically on my situation and unlocked it and provided the proper programming over the Internet. Do not rely on this to be the case. If you should decide to sell your truck, but wish to keep the chip components and programmer, you must “uninstall” the program, using the programmer, to unlock it from the VIN of your vehicle. It can then be installed on another vehicle, or the programmer can be used on another vehicle with the chip already installed.

My chip is a Bully Dog Triple Dog, which includes a small programmable monitor installed in the cab. It is an older model that is no longer manufactured. I have been pleased with the unit. The company is a small one and they were good to me when I needed their help. I was able to download from the Internet various unofficial programs for the unit, among which I found one I liked and have stuck with. In using these unofficial programs, I gave up some of the other functionalities of the programmer, such as the capability of adjusting my speedometer and odometer for tire size, and being able to read and clear vehicle error codes. If I were to go back to the Bully Dog factory settings, theses functionalities would be restored, but I would lose some performance. I prefer the performance.

Air Intakes

Much has written and said about the inefficiency of stock air cleaners on modern trucks. The fact is, they are pretty well engineered and effective. They represent a pretty good compromise between air flow, ease of maintenance, and cost of manufacture. Air flow, to a diesel, or any engine for that matter, is critical to the production of power, and therefore fuel efficiency. All late model diesel trucks are turbocharged. This means that all the air that goes into the air intake gets compressed in the turbo and shoved into the cylinders, where it is compressed even more, which causes it to heat up. It is combined with a tiny fog of fuel, which ignites under the heat and pressure, which, in turn, makes power to turn the crankshaft and eventually the rear wheels. The key is to get as much air into the turbo as possible. If you start that process with hot air, which is less dense than cold air, you get less air to compress, and therefore less air to burn with the fuel, resulting in less horsepower. If you have a restrictive air filter, or too small of an intake tube, you have the same problem.

To remedy this problem, after-market manufacturers have created what is know as a “cold-air intake” or CAI. A CAI attempts to get the air intake away from the hot air of the engine compartment and send a large volume of air to the turbo via a special air filter and a large tube. My truck came to me with one manufactured by AEM Induction Systems, which is highly regarded in the industry. Some manufacturers have claimed as high as  a 10% gain in horsepower and substantial increases in fuel efficiency. Since my truck came with the AEM CAI, I have no data to compare a stock air intake system, however, from the various forums I have participated in, few truck owners have realized any substantial fuel mileage increases after installing a CAI system. No more than 1 mpg should be expected over a regularly serviced stock system on a stock truck. The stock systems are pretty good.

On the other hand, there are a couple shortcomings of CAI systems. One enemy of a turbo charged engine is moisture in the air intake. Moisture in the intake tube can cause premature turbo bearing failure, excess wear on the turbo blades, and can damage expensive sensors, such as the Air-Flow Sensor, which communicate with the vehicles’s engine management computer. Removing the air intake from the protection of the stock air box may improve air flow a little, but also places it where it may be subject to splashes of water. Additionally, a wet air filter severely restricts the airflow through it. I have not experienced any detrimental effects that may be attributed to the AEM CAI in my truck. I am quite happy with it.

Some manufactures, such as AEM, use an air filter that must be cleaned regularly and is re-usable after cleaning. I have found mine to be durable and easy to clean, but after cleaning I have to let it drip-dry before I can re-install it and drive. Not nearly as simple as slapping in a new paper filter and driving away. As always, the manufacturers recommend expensive cleaning solutions that are specifically formulated in their labs to be compatible with the special materials used in their air filters. I have found a solution of warm water and dishwashing soap to work very well.

Four-inch Straight Exhaust System

My truck came with a 4-inch straight exhaust system already installed. There is no muffler, but there is a catalytic converter installed. It is illegal to remove any factory-installed equipment that affects environmental regulations. While diesel trucks manufactured prior to 2006 enjoyed little in the way of government required smog-control devices, those that were installed, such as the catalytic converter, must remain, the fact that your state/locale may not conduct inspections for such notwithstanding.

In my earlier life, I was quite into performance accessories for my cars and pickups that ran on gasoline. It seemed that the first thing anybody ever did to improve the performance of their vehicle was to install a set of “dual pipes” and exhaust headers. It was a well-documented fact that the installation of a set of headers was, dollar-for-dollar, the best way to improve engine horsepower. Improving the flow of exhaust gasses away from the exhaust ports of the engine, in fact, improves the performance of the engine. This is especially true of a turbocharged diesel engine. The turbocharger forces a high volume of air into the cylinders, but it can’t get air into the cylinders any faster than the exhaust system can get it out. As compressed air combusts, it expands at an explosive rate, which provides the power, so the exhaust system must be able to move air away from the engine faster than it comes in, because there is a higher volume. A high-flow, low-back-pressure exhaust system is essential for a diesel engine’s performance. Having said that, most late model trucks have pretty good exhaust systems on them. However, if you need to replace any portion of the exhaust system, I would recommend looking into having a large-diameter, say 4-5″ exhaust system installed. 4-inches should be more than sufficient for any truck that has not been modified for higher performance with something like a larger turbo. Again, do not expect fuel mileage gains over a couple miles per gallon, at most.

As always, there is a drawback to my straight exhaust system. While I love the deep rumbling, big-truck sound of my truck, when you are rolling down the highway at 70 miles-per-hour and the engine is at around 2100 RPM, the exhaust tone creates a very annoying and loud drone in the cab, particularly in the rear seat. Once I start hauling my horses over longer distances, hopefully in the near future, I will install a good quality, high-flow muffler, such as a Donaldson.

Exhaust Brake

I might mention something here that is not on my truck, but is on my wish-list. While it has nothing to do with fuel mileage, it is an accessory that improves safety while hauling a trailer. An exhaust brake is a very useful accessory for one who regularly tows trailers, particularly in mountainous regions. Diesel engines do not have the back-pressure a gasoline engine has, so it will not slow down the way a gas-engined truck will when the foot is lifted off the gas pedal. A diesel-engined truck will require more braking than a similar gas-engined truck on the same grade hill. To remedy this, large trucks use what is known as a “Jake Brake” (named after the original manufacturer, Jacobs), otherwise known as a compression brake, which uses the engine’s own compression to create braking power in the drive train. For our class of trucks, the exhaust system provides the braking power. While there are a several of types of exhaust brakes, they all work off the same principle: using back-pressure from the engine exhaust to act as a brake on the engine and drivetrain to assist the brakes at the wheels. This adds a true safety factor when hauling a heavy trailer down a long grade in the mountains, where regular vehicle brakes and trailer brakes can easily be over-heated. Two major manufacturers of exhaust brakes for our class of trucks are Pacbrake and BD-Power. Each uses a slightly different mechanism and both have good reputations for safety and reliability.

Free-Spin Manual Hubs

The next thing I’ll mention is the set of manual hubs I had installed. As I mentioned in the preamble, do not even consider buying a two-wheel-drive truck for hauling a horse trailer. The places you have to go to pick up and deliver horses, in addition to the places you will want to go to ride, will always have places that will get a two-wheel-drive truck stuck. The fuel mileage penalty for the four-wheel-drive front end, as I have stated, is only about 2mpg or so. In Dodge trucks, the four-wheel-drive system is a shift-on-the-fly system that has the front axle components turning anytime the vehicle is moving. That amounts to over 300 pounds of metal that is spinning for no reason when you are ambling down the highway, not to mention the unnecessary bearing and bushing wear in the components.

Several manufacturers have developed a manual hub that replaces the sealed unit bearings in the front wheels of Dodge trucks. The manual hubs allow the front axles to be disengaged from the wheels, allowing the axle and all the connected components up to the transfer case to remain at rest even while the vehicle is in motion. One such manufacturer is EMS Offroad, who markets their hub conversion under the name of Spyn-Tec.

Along about the time my truck passed 225,000 miles, one of my front bearings went bad. Dodge uses a sealed unit bearing which comes pre-assembled from the factory. There is no other way you can make this repair, but by replacing the entire unit, at a unit price of close to $500. I found the unit was very difficult to remove from the truck, even for a confirmed and experienced do-it-yourself-er like me. I had to take the truck to a garage to have the old unit removed and replaced. The cost estimate for this service brought the total repair cost up into the range where I decided to replace the units with the EMS Spyn-Tec Free-Spin manual hubs. This did two things for me: It gave me the option to unlock my hubs when I don’t need four-wheel-drive, which decreases wear on components and increases fuel mileage, and it gave me regular wheel bearings which I can service myself by simply cleaning them and repacking them with grease about every 50-75,000 miles or so. It was a no-brainer for me, particularly since I fully expected the other front wheel bearing to go fairly soon after the first. The total repair, including the new hubs ran about $2,500. Not much more than just having the Dodge unit bearings replaced.

Again, other ramifications. When the front hubs are disengaged, you can no longer “shift-on-the-fly”. If you have the hubs unlocked, you cannot use the 4WD shifter unless you are fully stopped. It will simply grind the gears. If you forget you have the hubs unlocked and try to shift into 4WD while moving, you may get it into neutral, but you will have to stop to get it engaged in any mode again. While you’re stopped, however, you can get out and lock the hubs. If it’s raining outside, or you are already stuck in the muck…well you see what I mean.

My fuel mileage gain measured out to be about 2mpg with the hubs unlocked under highway driving conditions, so I got back what may have been lost by buying a four-wheel-drive truck over a two-wheel-drive. During the winter, or during rainy weather, I simply lock the hubs and leave them locked. There is no harm in this. Just don’t drive around on pavement with the hubs locked and the shifter in four-wheel-drive.

I have been very pleased with the EMS hubs. Just make sure you provide the installation instructions to your installer and that he/she follows them to the letter. Sometimes an experienced mechanic figures he don’t need no stinkin’ instructions, but both he and you will regret it if he does not read and follow the manufacturer’s printed instructions. Take my word for it.

All the Rest

The rest of the accessories have little to do with fuel mileage, but I’ll go over them quickly, just for good measure. I wouldn’t have put them on my truck if I didn’t think they did some good.

Front Bumper

When I bought the truck, the big black bumper came with it. I did some research and found the manufacturer is Buckstop Truckware . It came with four great big holes in the bumper for driving lights, which, apparently, were removed by the previous owner.

The bumper is a $2,500 accessory (with the four holes), and I liked the look and protection it offered, so I was quite pleased. One thing I have on my wish-list is a 14-16,000 pound winch, which would be substantial enough to pull a 7,000lb truck and a horse trailer out of a ditch if necessary. Such a winch would require a very substantial bumper. The Buckstop bumper is such a bumper, and it comes with a built-in compartment for a winch. It is very well built of heavy steel and attaches to the truck frame with very substantial brackets and bolts. I’m quite sure it doesn’t help my fuel mileage.

Driving and Fog Lamps

It didn’t take me long, after buying the truck, to become very tired of the empty holes in the front bumper. It didn’t take me much longer to figure out how to justify buying fog and driving lamps to fill those holes. I found that the normal bright lights of the stock headlights are plenty bright for driving on the narrow, tree-lined Virginia roads, but when I got out onto some of the more rural and open roads in the western states, I was wishing for more light out farther ahead. I needed driving lights. I also concluded that a pair of yellow fog lights would be helpful in dense fog, since the headlights and driving lights are mounted fairly high, and white light in the fog can actually decrease visibility.

I contacted Buckstop Truckware to ask about their recommendations for driving and fog lamps, to make sure what I bought would fit the holes and mounting brackets correctly. I ended up ordering a set of PIAA lamps from Buckstop, both white and yellow, to fill the holes in my bumper. Happily, since I had a Buckstop Bumper, they offered me the same discount on the PIAA lamps that they give their customers with the purchase of a bumper. The cost of the lamps, with shipping, was about $450. Expensive, but they really put out some light!

Two-inch Front End Lift

I didn’t discover the two-inch lift pads in the front suspension until I bought new shock absorbers and installed them. Many owners of Dodge trucks will install lift kits in the front suspension to level the truck somewhat. The rear suspension of the 2500 and 3500 trucks is quite heavy and gives the truck something of a “stink-bug” look. The lift in a four-wheel-drive Dodge also has some utility, in that it provides a little more clearance between the front axle and the frame. There are several manufacturers of these kits, some of which are steel lifts, while others are polyurethane. I have no opinion on which is better. I have read that the increased height detracts from fuel mileage at highway speeds, but I suspect it makes no difference for in-town driving. I like the look of it, especially in conjunction with the large bumper.

Shock Absorbers

When the time came for me to replace shock absorbers…which was actually about 75,000 miles before I ever owned the truck…I went with Bilstein. I have used Bilstein shocks for heavy-duty and off-road applications for quite a few years and have never been disappointed. Not knowing I had a lift in the front suspension, I ordered the standard blue/yellow shocks recommended for my truck. However, if you have a lift on your truck, or intend to install one, you need to order the Bilstein 5100 (silver) shocks. They are specially designed for heavy and off-road use and are made to extend longer than a standard shock absorber, so they are perfect for the lifted suspension. The blue/yellow shocks will top-out (reach full extension) when you go over bumps, and will eventually fail if installed in suspensions with the 2-inch lift kit. I expect to have to replace my shocks again in the near future, due to this.

Ball Joints

All four-wheel-drive Dodge diesel trucks will need to have their ball joints replaced by the time they reach 175,000 miles. It’s just a simple fact of life…or engineering. When I bought my truck, I was assured by the dealer that the ball-joints had been inspected and were in good condition, so I assumed they had already been changed. When I went in to have the alignment checked after having new tires installed, the shop told me how lucky I was that neither ball joint had failed. They showed me that there was nearly 1/2-inch of play in both ball joints. I did some research on ball joints and read up on them on several forums and decided on Dynatrac ball joints. They carry an excellent warranty, are guaranteed to correctly fit the vehicle for which they are made, they are rebuildable without special tools, and they are require no maintenance (while they do not require maintenance lubrication, they do have grease zerks, so they can be greased if desired). Dynatrac’s reputation among experienced mechanics is unsurpassed. While they are more expensive than the regular replacement ball joints from parts stores, the failure rates of the less expensive ball joints overcame the price difference for me.

One Piece Drive Shaft

On the very same day that my front right wheel bearing went bad (see Spin-Free Manual Hubs), the carrier bearing in the middle of my driveshaft also gave up. I had gotten stuck in a ditch and had to use four-wheel-drive to get out. After getting out of the ditch, I noticed a noise in the front right bearing and found the bearing had gone bad. Later that day, as I was driving home from work, the carrier bearing gave way and nearly scared me to death with all the banging around. So, while the truck was down for the wheel bearing replacement, during which I ordered the manual hubs from EMS Offroad, I did some research on the carrier bearing issue.

I discovered that many people had complained about a vibration felt in the cab at low rpm and low speed in first, second, and sometimes third gears, just after letting out the clutch. I had felt this vibration as well, and had recognized it as a driveshaft vibration. This is quite common in a truck with a carrier bearing, so I had disregarded it. The driveshaft is actually engineered to compensate for this vibration via counterweight on a small flywheel on the front driveshaft yoke. Once it reaches a certain rotation speed, the vibration ceases. In reading some of the forum topics on Diesel Truck Resource forums I found that the carrier bearing was a weak point in the Dodge drivetrain and that it was a known problem area by both truck owners and the manufacturer. In fact, Dodge had begun to install one-piece driveshafts in many of the models that had previously had two-piece shafts. I found that many people had resolved this problem on their own by having a custom aluminum driveshaft fabricated, eliminating the carrier bearing. I contacted a local company that advertised that they made custom driveshafts for machinery, etc, and asked about the possibility. They said, “No problem, just give us the old shaft and we’ll make it to measure.” So, I had my shop pull the old drive shaft, while the truck was waiting for the front hubs to come in. The driveshaft place sent a driver by to pick it up. About a week later they dropped off a beautiful piece of work in the form of a 5-inch diameter aluminum tube, tig-welded to heavy-duty yokes on both ends, already mounted with U-joints and ready to be installed. My only disappointment was in the price. The quote they gave was $550, but when I got the driveshaft, the price was $750. The difference was that they had quoted the driveshaft thinking it used the standard U-joints for a Dodge 1-ton, but when they got the shaft, realized it had the heavy-duty U-joints used on the Dodge 3500 with the standard transmission. So, while I would have appreciated a call first, the price was still commensurate with what others were paying for similar driveshafts on the forums.

I have been very pleased with the driveshaft. I no longer have any vibration at any speed or engine RPM. Smooth as silk. And, I eliminated about the only weak spot in the Dodge 3500’s drive train.

Tires

When it came time for me to buy new tires, I got on the forums and asked around to see what tires folks were liking on their trucks. There were a number of people who were pretty happy with the Nitto Terra Grapplers, which had just come on the market recently (2010). I looked into them a bit and got some prices and compared them with other similar tires on the market. I shopped both on the Internet and at local tire shops. I located a set of them at Merchants Tire and Auto Center, in Stafford, Virginia, where I live, and took a look at them. I liked the tread design, because I wanted something that was fairly aggressive for mud and snow, while not being too loud on the highway. The folks on the forums seemed to agree that these tires fit that bill well. Surprisingly, I found the price at Merchants Tire to be better than the prices of Internet sources I found with the tire, including Tires Plus and Tire Rack, once you include shipping, mounting, balancing, and disposal fees in the total price. Merchants Tire also includes with the price of the tire, an alignment check and tire rotation, however, my truck will not fit on their alignment rack, so I don’t get that benefit.

My first set of tires reached about 40,000 miles before I had to start changing them out for inspection reasons. I’m sure I could have gotten another 10,000 miles out of them, but with dual rear wheels, you don’t want to change out individual tires if you can avoid it. I bought my second set just a few months ago. I’m still happy with the tire. I will try to remember to get these rotated about every 10,000 miles or so, and see if I can get a few more miles out of them.

Wrapping it Up

My truck is a very heavy-duty truck. Many of the accessories on it were installed in the interest of increased fuel efficiency. I have kept a very strict and consistent record of my fuel purchases and mileage since I bought the truck in March of 2009, at 208,000 miles. It recently passed 256,000 miles. I expect to own it when it passes 500,000 miles and beyond. With that in mind, when I buy an accessory or after-market replacement part for my truck, I look for the best part I can find. I don’t look for gold-plating or pretty polish. I look for durability, serviceability, and availability (read established and reputable manufacturer/supplier). While I never object to an inexpensive part, I have never bought a part for my truck based on price alone.

I have learned from experience and from real numbers and calculations that there is no magic part or combination thereof that will turn a 7,000 lb truck into a fuel efficient diesel sipper. No matter what combination of parts you put into your truck, or how much money you spend on them, you simply cannot increase the fuel mileage more than about 3-4 miles per gallon over the way it came from the factory. As the miles on your truck increase, it is likely that your fuel mileage will slip a little. That’s normal, and it’s simply fact. There’s no cure for it unless there is a particular part that is failing. If you can find that part and replace it, you might get back up to factory mileage.

My 2005 Dodge 3500 DRW gets very close to the same fuel mileage as did the 2000 Toyota Tacoma, with the 4-cylinder gas engine and five-speed manual transmission, that I owned before it. I’m happy with that.

My truck regularly gets about 14 miles per gallon in city driving, about 15 miles per gallon in town/rural driving (fewer stop lights), and 16-17 on the highway. In 2011 I hauled a car on a flatbed bumper-pull trailer from Virginia to Utah, at speeds up to 80 miles per hour, and averaged 12 miles per gallon. On the way back, I hauled a different, but similar car and about another 2,000 pounds of heavy tools on the same trailer. This time I kept my speed under 70 miles per hour all the way. I also added 1/2 ounce per gallon of 2-stroke oil to every tank of fuel. I averaged 14 miles per gallon. I once had a 1996 3/4 ton Ford pickup with a 360 CI gas engine and auto transmission that got 15 miles per gallon on its best day, and dropped town to between 6 and 9 miles per gallon with a full-sized camper on the bed. I’ll go with 14 miles per gallon anytime over that.

When I first bought the truck, I had hopes of getting it up to the low 20s on the highway with some of the accessories I added, but I’ve since accepted the fact that I have a big, heavy, heavy-duty truck, and that’s about as good as it is going to get. I’m ok with that.

I have also learned that when most folks talk about how they are getting 25 or 26 mpg from their trucks, that in general they are either looking at their “lie-o-meter” or they are simply making conversation and have no data to back it up. I have quit letting that kind of information bother me. I have been keeping hard numbers now since 2009 and I’m pretty comfortable that my numbers are real and not anecdotal. My truck has over 256,000 miles, four-wheel drive, dual rear wheels, sits high, and has a big, heavy front bumper, all of which combined costs me some fuel mileage in exchange for the benefits they provide. I also have added some accessories that reclaim some of that for me.  About 17 miles per gallon is the best I have come up with as a solid average for highway driving, by hand-calculated numbers over the past four years. That drops to between 12 and 14, depending on my speed, when I’m hauling.

Accessories I would still like to add:

• 8-ton electric winch in the front bumper
• Exhaust brake
• Under-the-hood arc welder
• Heavy-duty rear bumper with water-proof tool storage compartments
• Low-profile bed tool box
• Large capacity (60-75 gallon) fuel tank, either in bed under tool box or underneath.

So, there you have it. I truly enjoy my truck. In fact, there are few possessions I have ever owned that I have enjoyed more than my truck. I hope I have provided information that will be helpful to you as you look for your perfect truck and that may help you make more informed purchases of accessories and not be disappointed when you hear some folks talk about unrealistically high fuel mileage figures.

Tony 😉