Powertrain genealogy · provisional coverage
A borrowed Buick V6 sold back to GM. An AMC six that outlived AMC by two decades. A 1950s engine name revived on a modern turbo. Follow the powertrains and you follow the alliances, acquisitions, and changing missions.
The engine that won the war contract. Barney Roos rebuilt an unremarkable ~48 hp passenger-car four into 60 hp with 105 lb-ft of torque — enough to out-pull both the Bantam and Ford entries in the 1940 trials. Its power advantage is the single mechanical reason "Jeep" became a Willys word rather than a Bantam or Ford one. Powered the MB, GPW, CJ-2A, CJ-3A, and early wagons.
“Go Devil”
60 hp / 105 lb-ft (military rating)Same displacement as the Go Devil, but an F-head redesign lifted output roughly 25%. Its one famous consequence: the taller F134 would not fit under the CJ-3A hood, so in 1953 Willys raised the hood and grille to clear it — creating the CJ-3B's distinctive tall-hood silhouette, the shape Mitsubishi, Mahindra, VIASA and Hotchkiss then built under licence for decades. A single engine's height reshaped the Jeep's face worldwide.
“Hurricane”
~72 hpThe best engine story Jeep has. Kaiser Jeep bought the tooling for Buick's 225 "Fireball" V6 outright in 1966 and rebadged it "Dauntless" — a real power upgrade for the CJ-5/CJ-6. Then, during the 1970s oil crisis, General Motors bought the exact same tooling back from Jeep/AMC in 1974 and revived it as the Buick V6, which became one of the most-produced engines in American history. A Jeep engine and a Buick engine are literally the same casting, sold in a circle.
“Dauntless”
150 hp / 235 lb-ftThe largest-displacement engine ever offered in any Jeep — bigger even than the modern 6.4 L Hemi in the Wrangler 392 and Grand Cherokee. Offered in the full-size SJ Cherokee and Wagoneer with a forged crank and rods and a high-nickel block. The "biggest Jeep engine" and the "most powerful Jeep engine" are two different records: the 401 holds displacement, the supercharged Hellcat holds power.
The engine that outlived its maker. AMC developed the 4.0 from the 258 six in just 26 months and launched it in the 1987 Cherokee XJ — right as Chrysler was absorbing AMC. It became legendary for durability (200,000-plus miles routine) and kept the AMC engine bloodline alive inside Jeep for two decades after AMC itself vanished. The "boring" inline-six outlived AMC's glamorous V8s by decades.
“The 4.0”
173–190 hpThe most powerful Jeep ever, and at launch the most powerful SUV ever: the Grand Cherokee Trackhawk borrowed the Dodge Hellcat V8 for a ~3.5-second 0–60 mph SUV that still towed 7,200 lb. Production ended after 2021.
“Trackhawk”
707 hp / 645 lb-ftEverything old is new again: Stellantis's modern high-output inline-six is named "Hurricane" — deliberately reviving the name of the 1950s Willys F134 Hurricane four. The inline-six is back as Jeep's power engine, wearing a CJ-3B-era name, closing a 70-year loop.
“Hurricane (revived)”
up to 510 hp (high-output)