Five Unique Engine Options You Won’t Believe

Oil burners make great power, but how much is too much? For three years in a row, Audi’s 6L V12 biturbo powered their R10 prototype to victory at Le Mans. While they initially planned to cram it into the R8, the weight and packaging made the Q7 a somewhat logical choice. With cylinder banks opposed at 60* instead of 90*, it was also the smoothest diesel on the market.

De-tuned from the racing spec yielded 500 horsepower at all wheels along with 737 lb-ft of torque. Reaching the mythical 1,000 Nm at only 1,750 rpm made it an unquestionable sleeper, with the ability to return almost 21 mpg. The first issue it faced was a CO2 rating of 298 grams, or almost triple that of a Golf TDI of the same era.

It launched in Europe with a price tag of €130,600, (or $177,200), just ahead of the global recession. Only a handful were sold during a 5-year run, and they are regarded as the peak of diesel technology for passenger cars.

2014 Nissan Pathfinder Hybrid

A new Pathfinder arrived in 2013, and a new powertrain the year after. Instead of the venerable VQ35 V6, buyers could opt for a 2.5-liter supercharged four-cylinder backed by a continuously variable transmission (remember those?). Between them was a 20-horsepower pancake motor fed by a battery pack under the 3rd row. Although rated at 25 mpg city and 28 on the highway, many owners found the former being nearly impossible in traffic.

Even with a combined 250 horsepower and 243 lb-ft of torque, the weight of 4,788 lbs (2,171 kg) kept urban commuting at 19 mpg. If the battery capacity was more than 0.6 kWh it could have been a viable contender, but Nissan scrubbed it after less than a year of production. This was an expensive project with almost no return, so we hope they learned from the blunder.

1960 GMC Twin-Six V12

Before diesel cemented its reign over Heavy Duty trucks, GMC decided to give gasoline lovers one last celebration. Introduced in 1960, their line of 60-degree V6 engines ranged from 3L to 6.6L, with the 5.8 (351 ci) being the most common. Seeking to offer 200,000 miles between rebuilds, they made a wild decision to double the size, literally. Casting two V6 blocks as a common V12, it was topped by four individual cylinder heads, two intake manifolds, and individual two-barrel carburetors.

With 6 head bolts per cylinder and shaft-mounted rocker arms, it was suited for incredible torque at low RPM. A hydraulic governor used oil pressure and ignition timing to keep it under 2,500 rpm because the 180 lb (81 kg) crankshaft might come apart. The entire assembly tipped the scales at 1,500 lbs (680 kg), but it made up for this by offering 250 horsepower and a whopping 585 lb-ft of torque. These 11.5-liter beasts were sold in limited numbers until 1966, and they are now worth a small fortune for vintage truck enthusiasts.

2019 Cadillac Blackwing

Seeking to go head-to-head with German luxury, Cadillac spent millions to develop an all-new 4.2L V8. Their first twin-turbo, they were mounted inside the V for incredible response and offered 20 lbs of boost. A forged bottom end with cross-bolted main caps and piston oil squirters was topped by dual overhead cams, VVT, and direct injection. Seamlessly deactivating 4 cylinders under light loads offered decent fuel mileage, and it proved to be a perfect combination of all the latest technologies.

While it was not exclusively designed for the Cadillac CT6, that large sedan has been the engine’s only application so far. Offering 550 horsepower and 640 lb-ft (867 Nm), it was only offered for 2019 and half of 2020. With less than 1,400 ever offered, it would have made a perfect basis for the Z06 or the Escalade V, but it was shelved when the CT6 died of poor sales in early 2020.

1994 Toyota Previa Supercharged

Looking back at the world’s only mid-engine minivan, it was way ahead of its time. The Previa made use of a 2.4-liter four-cylinder slanted over at 75-degrees and mounted between the front seats. Accessories like the A/C and power steering were under the hood and connected to the crank by a jack shaft. While it offered incredible handling, it couldn’t compete with V6 power offered by the other family machines.

That’s why Toyota gave it a roots style supercharger in 1994, along with an air-to-air intercooler. It ran off a dedicated belt along with the other accessories up front, making it the only remote-mounted supercharger we know of. This offered 161 horsepower and 200 lb-ft (271 Nm), beating the other soccer moms with instant throttle response. Factory boost of 6 psi increased the fuel economy from 17 to 23 mpg, and power can be increased with a 93-octane tune.