Both engines are huge Mopar V8s, and both share a large number of applications. However, the engines are quite different from one another. From the outset, the 5.7-liter HEMI is substantially smaller than the 392 (6.4-liter) V8, and typically makes less power. The old adage “there’s no replacement for displacement” applies here. Next, you have to look at the application of each engine. While both HEMIs are relatively large V8s that are certainly capable of putting out a lot of power, the 392 is decidedly made for higher performance applications.
As such, the 392 is only available on Ram 2500 trucks, SRT Dodges, and a scant few Jeep Wranglers. Those are hardly run of the mill vehicles. The 392 cubic inch displacement is, in itself, a reference to the 1957 Chrysler 300C, which also housed a 392 V8. While not a weak engine by any means, the 5.7 HEMI has a more humble use case. It’s the base engine for higher trim Durango models, and available as an option on nearly every trim of Ram 1500 truck. It’s a workhorse that happens to be a lot of fun.
The 392 is a lot bigger and more powerful than the 5.7-liter HEMI. However, if street cred is your goal, either engine will work — the HEMI badge speaks for itself.
