The most powerful American production car engines ever made

As the 2011 horsepower Lotus Evija demonstrates, the most powerful cars of the near future will be EVs, but remarkable outputs have nevertheless been achieved with engines fuelled by petrol or diesel.

Here we’re looking at 20 of the strongest examples created in the US, all of them available in cars or non-commercial trucks sold to the public for road use (so no 11,000 horsepower Top Fuel dragsters, for example).

They’re listed in ascending order of their quoted outputs, with the caveat that there was a change from gross to net horsepower in 1972, which muddies the waters considerably.

Only the most powerful unit from any family is included. This means that what you’ll be reading isn’t a top 20 in the usual sense, since many engines have been ignored because they are outpowered by close relatives, but it adds variety, and we all like variety.

The FirePower was the first of three generations of Chrysler V8 engine collectively known as Hemi. Introduced in the 1951 model year, it was the only engine fitted to the first four models in the 300 letter series, each of which was produced for just a single year.

It was discontinued after the 300D of 1958, in which it produced 380 horsepower from 6.4 litres if fitted with twin four-barrel carburettors. Optional fuel injection raised the output to 390 horsepower, the highest achieved in any FirePower.

It’s important to note that this was a gross figure, measured when the engine was not burdened by power-sapping ancillaries necessary for it to function in a car. The net figure, as used from 1972 onwards, would have been lower, but still comfortably over 300 horsepower.

The RB was a big-block V8 offered in capacities of up to 7.2 litres, but the most powerful version fitted to a road car measured 6.8 litres. This was used in the 300F of 1960, in which it normally produced 375 horsepower gross. As an extra-cost option, customers could order a 400 horsepower version, which was mated to a four-speed manual gearbox rather than the usual three-speed automatic.

The highest gross figure for a 7.2 was 390 horsepower. The Max Wedge variant was rated at 420, but this was intended only for use in drag racing.

The MEL (which stood for Mercury-Edsel-Lincoln) was Ford’s rival to the contemporary Chrysler RB. In 7.0-litre form it was easily capable of producing 360 horsepower, which was the standard output of the Mercury Park Lane.

In 1958, however, Mercury offered an uprated version with three two-barrel carburettors. Known as the Super Marauder, it produced 400 horsepower, and was an option on every model Mercury sold in that year.

In 1970, the final model year of the first-generation front-wheel drive Toronado, Oldsmobile created the optional W-34 package to boost the output of its second-generation V8, which by that time had reached its maximum capacity of 7.5 litres.

As standard, the V8 was rated at 375 horsepower, which you might have thought would be about enough. The uprated camshaft and dual exhaust system included in the package raised this to 400, and for good measure Oldsmobile added “special transmission calibration for quicker acceleration”.

The first and only six-cylinder diesel on this list is a 6.7-litre member of the long-running B Series family, supplied by Cummins to Stellantis for use in its Ram heavy duty trucks. The Standard Output version produces 370 horsepower and is available in the 2500 and 3500, but the 3500 also has the option of the High Output derivative which produces 420 horsepower, 10 more than the 6.4-litre petrol Hemi V8 in the same range.

In terms of torque, the High Output easily surpasses the others. It produces 1075 lb ft, well above the Standard Output’s 850 lb ft and the Hemi’s 429 lb ft.

Originally intended only for racing, the first Chrysler V8 officially called Hemi (and nicknamed Elephant) later became available in several Chrysler, Plymouth and Dodge road cars – including the aerodynamically adventurous Dodge Charger Daytona and Plymouth Superbird – and also in the Monteverdi Hai built in Switzerland.

Measuring 7.0 litres, it was always officially rated at 425 horsepower gross, though in 1971 Chrysler and Plymouth also published a more realistic net rating of 350 horsepower.

PICTURE: Dodge Charger Daytona

The FE V8 made its debut in the 1958 model year, when the 5.9-litre version was fitted to several models produced by the ill-fated Edsel brand. Two 7.0-litre variants arrived later, of which the more powerful was known as the 427, even though its capacity in non-metric units was actually 426 cubic inches.

The 427 was available in two power outputs, the higher being 425 horsepower. In this form, which first appeared in 1964, it was fitted to the Ford Galaxie and Fairlane and the Mercury Comet, Monterey and Park Lane.

PICTURE: 1964 Ford Galaxie 500XL Sportsroof

The Godzilla is a petrol-fuelled V8 introduced in the 2020 model year with a capacity of 7.3 litres, and has since become available as a 6.8. It’s fitted to larger vehicles, and usually has an output of under 400 horsepower.

The exception is the version fitted to the F-Series Super Duty trucks, which are in what’s known as the Heavy Duty class. For this application, the 7.3-litre Godzilla produced 430 horsepower, and 485 lb ft of torque.

Chevrolet has been producing big-block V8s since the 1950s, though latterly they have been used more for load-hauling vehicles than for passenger cars. In 1970, the 7.4-litre version normally produced 360 horsepower, but it could optionally be uprated to 450 in that year’s Chevy Chevelle (pictured).

Another member of the same family which you can buy right now is the 10.4-litre ZZ632. This produces 1004 horsepower (net) and 876 lb ft of torque, but it’s a crate engine not fitted as standard to any production model, so for the purposes of this gallery it doesn’t count.

The L5P became the newest member of the 6.6-litre turbo diesel Duramax V8 family in 2017, when it produced 445 horsepower at 2800rpm and 910 lb ft at 1600rpm. For 2024, it has been upgraded to 470 horsepower and 975 lb ft at the same engine speeds.

It’s fitted to two very similar Heavy Duty pickup trucks – the Chevrolet Silverado HD (pictured) and the GMC Sierra HD, the latter being more or less the same as the former but with different badges and styling details.

Also known as the Scorpion, the 6.7-litre turbo diesel Power Stroke V8 was introduced in 2011, replacing an earlier 6.4-litre engine from the same family, and has gradually become more powerful. Its 475 horsepower and 1050 lb ft were both best-in-class and a High Output version arrived in the 2023 model year with 500 horsepower and 1200 lb ft.

The High Output is standard in the top-spec Limited versions of the F-250, F-350 (pictured) and F-450 Super Duty trucks, and an extra-cost option in others.

Codenamed LTA, the Blackwing was a 4.2-litre twin-turbo V8 available very briefly in the Cadillac CT6 luxury saloon. In the CT6 Platinum, it produced 500 horsepower and 574 lb ft, while a version in a higher state of tune fitted to the CT6-V (pictured) made 550 horsepower and 640 lb ft.

Introduced in 2019, both models lasted only until the CT6 range was discontinued the following year. Today, Cadillac makes Blackwing versions of the CT4-V and CT5-V, but neither they nor any other vehicle use this engine.

The Viper V10 engine was only ever used in the Dodge Viper sports car. As launched in 1992, it already measured a formidable 8.0 litres, but its capacity was gradually increased over the years, finally reaching 8.4 litres.

The power and torque outputs rose too, peaking at 645 horsepower and 600 lb ft in 2015.

Of the many Ford engines wearing the EcoBoost badge, the twin-turbo 3.5-litre V6 is by far the strongest. As far as road-going applications are concerned, the ultimate version was the one fitted to later examples of the Ford GT, which produced 660 horsepower and 550 lb ft of torque.

Still higher figures have been reached, but only in GTs built specifically for track, rather than road, use.

The most powerful engine in the Modular family is also the most powerful ever fitted to a production Ford. Known as the Predator, the supercharged 5.2-litre V8 produces 760 horsepower and 625 lb ft, and has only ever been fitted to the Mustang Shelby GT500 introduced in 2020.

Another version called Carnivore made its debut in the 2023 F-150 Raptor high-performance pickup truck. Developed with off-roading in mind, this has slightly less power – a still more than reasonable 700 horsepower – but a superior torque rating of 640 lb ft.

Of the many Chevrolet V8s bearing this name over the past 70 years, the most powerful fitted to a production car has been the supercharged 6.2-litre LT5 introduced in the 2019 Corvette ZR1. Its standard output was 755 horsepower, but it made 772 horsepower when fitted with the optional Performance Intake system.

At the time of writing, no current-generation mid-engined Corvette produces anything like this, though that may be about to change.

The SRT Demon 170, the seventh and final Last Call special edition versions of the Dodge  Challenger, was powered by the most monumental production engine in Hemi history. If it sensed that it was running on E85 fuel, the supercharged 6.2-litre V8 could produce no less than 1025 horsepower and 945 lb ft of torque. On E10 fuel, the figures were a still astonishing 900 horsepower and 810 lb ft.

At launch, Chrysler said that production would be “limited to at most 3,300 units”, 300 of which would be sold in Canada and the remained in the US.

All versions of the Saleen S7 were powered by a 7.0-litre engine derived from the Ford Windsor V8. Power outputs varied considerably depending on how much, if any, forced induction was involved, but in twin-turbo form it was said to be as much as 1300 horsepower.

That claim was superseded by one made in 2019, when Saleen reported that the figure had been raised to 1500 horsepower and 1328 lb ft of torque.

The Tuatara hypercar produced by SSC North America (formerly Shelby SuperCars) has a mid-mounted twin-turbo 5.9-litre V8 engine whose output depends on what fuel it’s running on. According to its maker, it produces 1350 horsepower on 91 octane petrol and 1750 horsepower on ethanol or methanol.

A video released in 2022 shows the engine apparently achieving just short of 1900 horsepower on the Nelson Racing Engines dyno, though this is not an official figure.

With a performance upgrade, and only if running on methanol, the V8 is reported to be capable of 2200 horsepower in the Aggressor variant, but this is a track-only car whose performance, according to the SSC website, is “not possible in the street legal versions of the Tuatara”.

Hennessey’s Venom F5 is available in four forms – Coupe, Roadster (pictured), Revolution Coupe and Revolution Roadster – of which the first and third had been sold out at the time of writing. All four are powered by the Fury engine, a 6.6-litre twin-turbo V8.

In each application, it produces 1817 horsepower and 1193 lb ft of torque, which makes the Venom F5 the most powerful non-electric road-going production car not only in the US but in global automotive history.