That concept would melt its clear acrylic hood if the engine ran too long, but this month, we got a chance to test drive a production mule, an otherwise normal Frontier with a Cummins 2.8-liter diesel four-pot under the hood and a ZF eight-speed automatic changing gears. The powertrain figures to be a direct competitor to the 2.8-liter Duramax promised for General Motors' Chevrolet Colorado and GMC Canyon twins, but will Nissan build it? All signs point to probably. Officially, Nissan is taking no position on the future of this program, but a concept followed by putting journalists into a test mule suggests the company is considering the option very seriously. Here's what we gleaned from a brief drive around the posh suburbs of Nashville:
- Before we get too deep into this Quick Spin, realize this Frontier is absolutely a mule, not a prototype. More or less cobbled together with duct tape and baling wire, it's not meant to be representative of a finished product, or even a started product. The transmission and shifter is straight out of a Chrysler 300 and the shifter surround is cut out of a panel of plastic. The "Low Sulfur Diesel Only" sticker is, well, just stuck on. We're looking at a "What if?" mockup.
- The engine is essentially a tweaked version of a Chinese-built, gray-iron 2.8-liter four cylinder. With 16 valves, the obligatory turbocharger and common-rail injection, this Cummins engine is already used for on- and off-highway applications. In things like generators, small earth-moving machines and large turf-management equipment (giant lawnmowers) it carries the "QSF" label, and for cabover trucks in Asia and other on-road applications, it's dubbed ISF. Some tunes offer as few as 49 hp, but it'll run until the sun explodes.
- This truck gets an intercooler up front wedged behind the grille, and combined with the base software, it develops 200 horses and a stout 350 lb-ft of torque, but this is not yet the smooth, quiet modern diesel we've come to expect. She's a rough character, albeit with a caveat: There has been zero software tuning done for the Frontier mule. Smoothness in a diesel comes from precisely controlling combustion, and while the engine is capable of eight fuel-injection events per cycle, there are only two with this software. Clatter, clatter, clatter, clatter.
- It may be loud at idle and under acceleration, but this dog offers bite to match its bark. Tons of torque and eager throttle response at times overwhelms the ZF gearbox (which also hasn't really been tuned) and a "ka-chunk!" shift squawks the rear tires. Midway through full-throttle acceleration, the turbo's wastegate locks closed and the engine really takes off, revving ahead quicker than the bottom of the range.
- At cruising speed, though, this is a surprisingly smooth and easygoing engine, almost quiet even. That shouldn't really be a surprise since tugging the weight of a truck and passengers is akin to a quarter horse pulling a little red wagon.
- Although nobody ever confirmed the product plan before Nissan's PR team put the clamps on its engineering staff, we were able to gather a few juicy tidbits about the program. One unnamed official let slip that engineers are targeting 2019 diesel emissions and particulate requirements for the rig, which may indicate potential production timing. Another interesting item is Cummins would consider shifting to a compacted graphite iron block with an aluminum head to cut down on weight and improve performance. Finally, Cummins prefers to build where it sells, so US domestic production for the engine would be seriously considered if a Frontier Diesel gets a green light.