Diesel fuel has long been the favorite power source of military and peacekeeping vehicles throughout the world. Diesel engines are some of the most rugged, and long-lived powerplants in internal combustion terms. Diesel fuels can range in blends to optimize various characteristics such as cetane number, cold weather performance, warm weather performance, etc. Vehicles belonging to North Atlantic Treaty Organization (NATO) countries are largely powered by diesel, and many of these vehicles make it into the commercial consumer market by way of auction, surplus, and decomission procedures. In this article, we hope to shed some light on the political agendas that drove diesel into NATO’s ranks, and highlight some of the vehicles we most commonly see in civilian hands.
Single Fuel Concept
In 1988, the U.S. military adopted a policy of a single fuel source for all ground-based vehicles. According to Lieutenant Colonel Russell K. Garrett, in his report, Is a Single Fuel on the Battlefield Still a Viable Option? “In 1988, the Army Energy Office requested the Belvoir Research, Development, and Engineering Center (BRDEC) conduct a demonstration to confirm the usability of JP-8 for continuous operation in all diesel fuel-consuming vehicles and equipment.”
In 1988, the Army Energy Office requested the Belvoir Research, Development, and Engineering Center (BRDEC) conduct a demonstration to confirm the usability of JP-8 for continuous operation in all diesel fuel-consuming vehicles and equipment. -Lieutenant Colonel Russell K. Garrett
By making a single fuel the standard for all vehicles, the logistics of availability become much simpler. The risk of mis-fueling would become almost an impossibility, and many other benefits would follow. The weakness of the idea of a single fuel is with anything like this; compromise. Vehicles and engines may have to compromise performance, or reliability in favor of modularity. If all vehicles are asked to run on the same fuel, some of those vehicles will have to be retrofitted to run on a fuel less ideal for their given application.
“Over 2,850 diesel fuel-consuming vehicles were converted and operated satisfactorily on JP-8,” explained Garrett. An aviation fuel may be interchangeable with a diesel fuel, but they are certainly not the same, nor do they contain the properties idealized for each vehicle. The use of diesel over gasoline is a clear direction of military planners, detailed by Garrett. “There is an ongoing vehicle/equipment modernization program in which gasoline engine-powered equipment is being replaced by diesel engine-driven equipment,” he said. In examining real world testing, and experience the thesis of Lieutenant Colonel Garrett’s paper states “…a single fuel on the battlefield is indeed a viable option, and one which DOD should continue to seek.”
NATO Diesel Fuels
Chapter 18 of the NATO Logistics Handbook discusses the various fuels employed by all vehicles operating under the participating countries’ command. While jet fuel, gasoline, oils, and lubricants are a big part of the document, diesel fuels are also given specific denotations for appropriate applications. Of course, different vehicles require different forms of diesel fuel based on the environment in which they operate, the speed they run, and other considerations.
There are four main fuel designations for diesel engines. These fuels all carry the prefix “F” followed by a number. The number is the distinguishing factor when comparing NATO fuels. These four fuels are; F-54, F-65, F-75, and F-77. Jet fuels have also been tested for use in diesel applications, as mentioned in Garrett’s article, these include JP-8 and some kerosene derivative fuels like DF-1, and DF-A.
According to the NATO Logistics Handbook:
F-54 “is a military fuel used in compression ignition engines in NATO Europe areas outside Denmark, Greece, Italy, Portugal, Spain, and the United Kingdom.”
F-65 is a “low temperature diesel/kerosene blend.”
F-34 “is a military kerosene-type aviation turbine fuel with Fuel System Icing Inhibitor (FSII) … Also known as JP-8 or AVTUR/FSII.”
F-44 “is a military high flash point kerosene type aviation turbine fuel with FSII used by ship borne military gas turbine engine aircraft in most NATO countries. Also known as JP-5 or AVCAT/FSII JET A and JET B.”
Surplus military vehicles have a popular following and enthusiast base. Some people are attracted to the strong components like axles, transfer cases, and knuckles. Some like the rugged utilitarian style of these field-tested and proven rigs. Off-roaders, rock crawlers, hot-rodders, and collectors covet these macho trucks, and it’s no wonder — hardly anyone is immune from the “cool-factor” these rigs exude.
In our next section we will take the time to highlight some of the vehicles most commonly found in the hands enthusiasts, but remain products of the NATO-driven single fuel concept. Vehicles that fall under this movement in military industrial complex politics are not limited to transport. Generators, tanks, aircraft, and marine applications are all subject to the goals of standardizing fuel under NATO.
High Mobility Multipurpose Wheeled Vehicles (HMMWV)
Better known as the “Humvee,” the High Mobility Multipurpose Wheeled Vehicle, or HMMWV, has been the standard light transport for the U.S. Armed Forces since the mid 1980s. The U.S. military needed a replacement for the good old Willys Jeep, something more rugged, with a higher load-carrying capacity, and more versatility etc. Produced by AM General, the ink on the contract was barely dry in 1983, when production on the first delivery of more than 2,000 vehicles began. Approximately 100,000 HMMWVs were produced for foreign and domestic customers between 1983 and 1995.
The HMMWV featured two engine options throughout it’s production; a 6.2-liter naturally-aspirated diesel V8, and a 6.5-liter turbocharged diesel V8 in later models. The later engine was clearly derated to a disappointingly low 190 horsepower, and 380 lb-ft of torque. Transmissions were either three or four-speed automatics.
The real defining feature of the HMMWV, apart from the classic military industrial complex-style body lines, is the four-wheel independent suspension. Inboard brakes for lower unsprung weight, and protection were fitted to portal axles. Differentials are torque biasing for traction in loose terrain, and a whopping 16 inches of ground clearance down the center allows the HMMWV to clear tall obstacles. Onboard tire pressure monitoring was adopted in this early example of off-road technology, allowing occupants to control the flotation provided by the huge 37×12.5-inch tires.
After their initial battlefield trials in Operation Just Cause, Panama 1989, the reality of in-the-field testing exposed weak spots in the HUMMWV and adaptations and variations of this modular vehicle began to hit drawing boards. The M1114 was an armored version designed to sustain small arms fire. In order to accommodate the additional weight of bullet-resistant glass and paneling, many upgrades were necessary to the initial design. Forced induction in the form of turbocharging added some power to move the heavy M1114, uprated suspension supported the load, and air-conditioning kept the inside climate tolerable while retaining a closed cab for armor and security.
The most modern incarnation of the HMMWV is the M1151, a modernized version of the M1114. In today’s world of unconventional conflicts, and Improvised Explosive Devices (IEDs), a purpose-built transport was necessary to improve occupant safety. Rather than a complete redesign, retrofit kits were developed to allow Armed Forces to make changes in the field, and adapt their vehicles to mission specific needs. Referred to as Armor Survivability Kits (ASKs), these kits included armor designed by the U.S. Army Research Laboratory, however exact contents are classified.
Of course, we all know of the civilian version of the HMMWV, the H1 Hummer. Allegedly the product of a custom order by Arnold Schwarzenegger, the H1 was a military transport for the rich and famous. Complete with all the normal amenities for a luxury truck, the H1 retained the military-tested drivetrain, suspension, and aesthetic, making it an off-road toy for the likes of celebrities and movie stars. Military surplus HMMWVs are commonly available through auction houses for a fraction of the price of an H1, but they come with luxury interior the Department of Defense checked on the options list, and have a limited top speed of between 50-70 mph depending on the configuration.
The Unimog is a military transport vehicle produced by Mercedes-Benz for the German Military. Surplus Unimogs are famed for their off-road capability due to extreme high ground clearance. Available in many configurations to suit the needs of the end user, these trucks are produced with either four-by-four, or six-by-six wheel-drive, making even the toughest terrain accessible. Originating in the 1940s the design is reminiscent of transports from old movies, and has changed very little over the decades.
Variants are in use by dozens of military forces around the world, including NATO countries such as Britain, Belgium, France, Greece, Germany, and others. Early Unimogs had one diesel powerplant option and two gasoline options. A 2.2-liter straight four-cylinder known as the Mercedes Benz OM615 is the diesel engine. The second generation Unimog came with a 4.8-liter turbo charged OM 924 LA straight-four. The most recent generation of Unimog was introduced in 2013 and features a 5.1-liter turbocharged OM 934 LA straight-four. The latest engine produces 231 horsepower and 664 lb-ft of torque.
The M35 is a two and a half-ton cargo vehicle that was originally designed in 1949, and has scarcely changed design in 60 years. This 15,000-pound plus truck has been manufactured under license by several companies around the world, including REO, Kaiser, AM General, Kia, and Bombardier. Powered by a 7.8-liter turbo-diesel LDT465, this inline-six-cylinder engine produces a modest 134 horsepower. All M35 trucks include a manual five-speed transmission coupled to a two-range transfer case for low gearing.
The key attractive features of the M35 to aftermarket gearheads are the axles and brakes. This six wheel-drive transport vehicle rides on giant Rockwell axles, prized for their durability by off-roaders everywhere. The M35 has air-assisted hydraulic brakes, and incredibly due to the vehicles weight of under 26,000-pounds, a commercial driver’s license is not necessary to operate this truck on public roads.
These trucks also have a huge following among enthusiasts. “Bobbed-deuces” eliminate the third axle to shorten the wheelbase and make for a more nimble off-road rig. Restored and hot-rodded customs take this truck from classic olive drab to a pallet of candied colors. The existing drivetrain makes them desirable candidates for crawling rigs at a fraction of the price of new manufacturer parts such as axles and transfer cases.
The Land Rover Defender is the no-frills genesis of today’s luxury Range Rovers, and Discoveries. Acting as the Jeep and Humvee for Americans troops, the British used this light transport vehicle as the standard vehicle for getting around the battlefield, until the modern un conventions of warfare sounded it’s obsolescence.
These short wheelbase, four-by-four trucks are comparable to Toyota FJ40s, Broncos, Blazers, and other solid axle off-roaders. Diesel powerplants for the Defender came from a few sources. Ford 2.2-liter and 2.4-liter engines powered the last Land Rovers produced. Earlier Defenders came with 2.5-liter TDI turbodiesel straight four-cylinder engines.
While the NATO goal of a single fuel may be a future reality for government motorpools, and fleet vehicles, it is not an imminent change. The civilian consumer can take comfort in knowing the versatility of the surplus vehicles available but can retain the option to run fuels of their choice. The logistical problems and solutions of the single fuel concept are a puzzle for military scholars, not the weekend wheeler. We hope a look into the NATO toy box of diesels has inspired you to look at surplus military vehicles for your next project.