Building upon a hundred years of engineering experience, car manufacturers in the '90s and 2000s refined and introduced many of the greatest engines that ever went into production cars. Some live today. Others have passed on, not because they failed their duties or weren't loved by enthusiasts, but because of the hard realities of toughening emissions standards, demand for greater fuel economy, and integration with newer fuel-saving technologies. These 10 motors met their ends too soon, but all became—and remain—legends in the shop and at the racetrack.
Jeep 4.0L Straight Six
Most notably found in: 1997-2006 Jeep Wrangler
AMC introduced its straight six in 1964, but it didn't become a legend until Chrysler bought AMC—and Jeep—in 1987. Under Chrysler's watch, Jeep furthered the rollout of the AMC-developed 4.0L PowerTech and stuck it into most of its lineup, including the XJ Cherokee, MJ Comanche, YJ Wrangler, and ZJ Grand Cherokee.
The engine was torquey and powerful for its day, with 190 horsepower by 1990, and as reliable as a block of wood. Going 200,000 miles before a rebuild is expected, not an achievement, and this six can suffer running conditions that'd kill most motors. When the TJ Wrangler ended production after 2006 and the JK Wrangler took over, Mopar killed the 4.0L because it was too awesome—or because it couldn't satisfy Jeep's need for better emissions and fuel economy numbers. Maybe a little of both.
Most notably found in: 1999-2002 Nissan Silvia
The SR20DET was the kind of peaky, rev-happy, turbocharged and intercooled motor that matched the knife-edged character of the sports cars it came in, like the Nissan 180SX. It's often pitted against Nissan's other legendary inline-four of the time, the naturally aspirated KA24DE, which is what the brand gave the U.S. and Canada. That powerplant is more often a truck motor than a car motor, but Nissan believed Americans would appreciate its tilt toward low-end torque, even in the 240SX (our version of the 180SX). The KA24DE was a solid motor, sure, and it built up a strong tuning scene that's still going today. But SR20DET swaps are popular for a very good reason.
Most notably found in: 1993-2002 Toyota Supra
The inline-six 2JZ-GTE was the top motor in the MkIV Supra that helped Japan dominate the '90s performance car market. Sequential turbochargers cut down on turbo lag—the delay between pressing the accelerator pedal and receiving the turbo's extra power—by having a smaller turbo spool up first at lower RPM while a larger turbo spooled up to deliver even more power at higher RPM. It created a meaty, flat torque band from below 2,000 RPM all the way to the other end of the tachometer.
Compared to the Mazda RX-7 FD, Nissan 300ZX Z32, and Mitsubishi 3000GT competition at the time, the Supra had the stoutest motor. The 2JZ-GTE was overbuilt to withstand huge amounts of power and could be modified to withstand even more. There are modified 2JZ-GTEs out there making 1,000 horsepower for drag strip racers, and people have been making 700- and 800-horsepower street-legal Supras for so long it's not even news anymore.
Most notably found in: 1999-2009 Honda S2000
Built for the 1999 debut of the Honda S2000, the F20C was a naturally aspirated 2.0-liter I4 that spat 240 horsepower through the rear wheels of the 2,800-pound sports car. Those are healthy numbers for the late '90s, back when a small non-turbo engine cracking 200 horsepower was a big deal.
This Honda motor was a screamer with a wail like a superbike. Until the 2010 Ferrari 458 came along, the F20C put out the best horsepower-per-liter figure in the industry, and a redline higher than anything else on the market. For 2004, Honda swapped out the F20C for the F22C1 version of the motor, which was then a North American exclusive. The engine was stroked to 2.2 liters for a slight torque boost and more oomph on the lower end of the power band, but it came at the cost of lobbing 1,000 RPM off the glorious, ear-drum-assaulting redline of the original.
Most notably found in: 1999-2002 Nissan Skyline GT-R
Notice the theme here? Japan was on a roll with terrifically well-engineered motors in the '90s and endeared these cars to generations of enthusiasts. The RB26DETT is another example of '90s love for the straight-six, and like its Toyota counterpart from the Supra, it also had sequential twin turbochargers.
The Skyline GT-R R34, in which the engine was standard, was the last Skyline-based GT-R and part of a Japanese tradition of taking ordinary family cars and slapping on loads of exotic technology, powerful engines, and crazy plastic body effects. Nissan never sold the Skyline GT-R in the United States or Canada, but the RB26DETT is a popular motor to ship over from Japan and swap into everything from Datsun Z-cars to 240SXs and 300ZXs.
Ferrari Dino 3.6L V8
Most notably found in: 1999-2004 Ferrari 360
The V8 version of Ferrari's classic Dino had a flat-plane crankshaft design as opposed to the more common cross-plane design of typical American V8s. That's why a Ferrari's V8 sounds like two buzzy I4s in sync rather than the deep, threatening growl of an American muscle car. The flat-plane crankshaft doesn't need heavy counterweights like the cross-plane, so the motor raises and drops its revs quicker and feels more responsive to throttle inputs.
When the F430 took over from the 360 in 2005, it came with a new V8 jointly developed with once-longtime rival Maserati, owned now by Ferrari. That engine finally sent the Dino into the history books for good.
Most notably found in: 1998-2003 BMW M5
Speaking of cross-plane V8s, the S62 was BMW's hot-rodded version of the workhorse M62 V8 that peppered the upper end of its model lineup. Engineers increased the bore and stroke of the M62 to 5.0 liters, increased the compression ratio, and gave it an electrically controlled throttle body for every cylinder.
The engine also got BMW's variable valve timing, VANOS, that could change how the engine's valves opened and closed based upon how fast the motor was running to maximize power delivery across the whole power band. Rather than the run-of-the-mill system that only worked the intake valves, the S62 got “double VANOS”, in which the motor could also manipulate the exhaust valves. Part of the reason why the value of BMW E39 M5s are skyrocketing into the classic car stratosphere ten years too early is because the car came with the S62.
Porsche Air-Cooled Flat Six
Most notably found in: 1994-1998 Porsche 911
Here is the ultimate iteration of the legendary air-cooled flat six that powered every 911 since it was born in 1963. The 993, which went out of production in 1998, was the last generation of 911 to get the motor. It was also the only one to incorporate VarioRam, Porsche's method for varying the length of the air intake's ducting based upon engine demands. At low RPM, the intake lengthened to improve low-end torque, and as RPM increased, the intake shortened to improve high-end power.
Ever since the 993 was replaced for 1999 by the new 996 generation, all of Porsche's engines have been water-cooled. Porsche took the air-cooled engine as far as it could, but the design was limited by its ability to shed heat, and so even the ultra-traditionalist company wouldn't justify keeping it in production as buyers got used to (and then began to expect) horsepower in the high 300s and 400s. Porsche's water-cooled engines pushed power levels higher than they ever could have gone with the original 911 motor, but purists still go weak in the knees for the air-cooled motor.
General Motors LS6
Most notably found in: 2004-2005 Cadillac CTS-V
While officially designated as Generation III of the small block Chevrolet (SBC) V8, the LS family was a clean-sheet design distinct from the preceding Gen II. The LS6 emerged from that family as an icon. It was a hotter variant of the LS1 that was standard in the C5 Corvette and optional as the V8 motor for '98-02 Camaros, Firebirds, and Trans Ams.
The souped-up LS6 was reserved only for the top-of-the-line C5 Corvette Z06 and the 2004-'05 Cadillac CTS-V. Even so, it was a great value for a motor of the early 2000s. Like the other Gen III LS motors, the LS6's cylinder heads and block were made of aluminum to bring down the weight. Even though it was a relatively more primitive overhead-valve engine, it was also a powerful, affordable, easy-to-maintain motor that responded extraordinarily well to tuning. So much so that it, like the LS1, became a favorite to swap into not only older GM cars but also Nissans, Datsuns, Toyotas, Mazdas, Volvos, Mercedes, performance trucks, and kit cars.
And every once in a while, somebody swaps one into a Mustang and makes the Ford faithful fume.
Alfa Romeo Busso V6 12V
Most notably found in: 1993-2004 Alfa Romeo Spider
Not familiar with this one? One of the most beautiful engines ever made, the Busso is also the sweetest-sounding production V6 engines (you could argue the V6 version of the Ferrari Dino should share the honor, but the Busso is second-to-none).
Alfa began replacing the Busso with the JTS I4 and V6 engine family, co-developed with General Motors, in the 2000s. As glorious as the JTS sounds, it just doesn't hold a candle to the original Busso. There's a reason we left this one for last. Go on, now, and onto YouTube to listen to videos of Busso Alfas revving around race tracks.