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Detonation; Diesel in the Dirt


John Lehenbauer
Jun 4, 2018
Photographers: John Lehenbauer
The popularity of diesel engines has boomed in recent years here in the U.S. Domestic truck manufacturers continue to developed new, and enhance existing vehicles with diesel powerplants. The engines are being installed in everything from commuter cars to 1-ton pickup trucks. And, consumers’ enthusiasm for diesel has steadily increased the number of oil-burners that are on the road.
The growing popularity is not limited only to the engines being optional in certain vehicles. It is becoming the powerplant choice for a lot of people who perform engine swaps and build custom rides. Diesel engines in a wide range of configurations (I-4, I-6, V-6, and V-8) and brands can be found in hot rods, old pickups, drag cars, and off-road rigs.
In March of 2018, I was in Moab, Utah, for the annual Easter Jeep Safari (an off-road gathering). I was there working with folks from some of the Fourwheeler Network’s titles and noticed a ton (figuratively speaking) of diesel-powered off-road vehicles running about. In past years there were always a few, but this time there seemed to be far more than I remember. I am not really talking about the heavy concentration of oil-burning tow vehicles that also seem to grow in number each year as well. The thing that really caught my attention is the boom in popularity of the off-road rigs.
Photo 2/3   |   This custom Cummins-powered Dodge Ram trail rig made short work of this obstacle (and every other) on the Fins & Things trail in Moab, Utah. The torque of the big Cummins along with a high-clearance bed and large tires makes this a very capable rig.
Being that the event has been Jeepcentric for over 50 years, diesel-powered off-road rigs are not something that was normally seen. All of the Jeeps, Toyotas, Chevrolets, Fords, etc. that have converged on the area throughout the half-century have been predominately gas powered. This was due partially to the fact that there were not a lot of factory diesel options and usable oil-burners to swap (non-ideal size/weight, power, availability, and support). So, historically, when owners bought a vehicle or did an engine swap they went with engines that were easy to get, work on, and maintain. Hence the use of and swapping of gas engines.
This trend is beginning to change. Diesel-engine availability has increased substantially, thanks to Cummins crate-engine offerings and the large number of vehicles on the road. Vehicles in service are beginning to age, which increases the availability of engines that can be used to build a four-wheeler. It is becoming far more common to forgo transplanting the traditional spark-plug engines for a compression-ignition unit. Many builders are enjoying the advantages that diesel provides over gas, like ample torque, fuel economy, and reliability. The ever-growing aftermarket support also helps make oil burners more appeasing.
Some of the more popular engines I saw being used in swaps were the Cummins 4BT, Cummins R2.8, and Volkswagen TDI. They were found in a variety of vehicles: Jeeps (from flat fender Willys to JKs), Broncos, Toyotas, Suzukis, and even some custom-built rigs. Of course, everyone loves what compound turbochargers, big injectors, and such can do, but when you’re in the middle of nowhere and a tow truck is not an option, having a reliable and easy-to-work-on engine is more important. That is why so many of the oil-burner transplants remain very close to stock.
Photo 3/3   |   A Chevrolet Colorado with the 2.8L Duramax engine and 37-inch tires looks good assaulting the slick rock of Moab, Utah.
The remaining drivetrain hardware behind the engines varies as much as the vehicles do. Installers use everything from stock arrangements with adaptors to custom heavy-duty setups. Many of the stouter setups are not intended to support the engine’s output as much as the larger tire sizes (possibly 37-inch or bigger) many run and how the rig will be used (easy trails or hardcore rock crawling).
Along with all of the vehicles that have had swaps performed on them, a lot more vehicles with factory-installed diesels were trekking around in the dirt. There were quite a few older trail-worn fullsize trucks (Dodges, Fords, and Chevrolets) some with clearanced body panels (by tools and rocks), big tires, and custom beds. There were even some very clean rides that don’t normally see a lot of dirt, braving off-road perils. I got to see a good variety when I tagged along on the Diesel Fullsize Invasion hosted by Bullet Proof Diesel. It was also great to see Chevrolet Colorados with the 2.8L Duramax and Nissans Titans with the 5.0L Cummins V-8 romping about.
I don’t see diesel’s popularity subsiding anytime soon in the off-road community, especially with the introduction of a diesel option for the Jeep JL that’s coming by 2019, and the possibility that the new Ford Ranger may have the option as well.


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