Chrysler announced its new-generation 5.7-liter Hemi engine with the introduction of the 2009 Dodge Ram in January. We now know that the engine will replace the old V-8 on all of the company’s 5.7-liter Hemi-powered offerings. (SRT 6.1-liter V-8s remain unchanged. And awesome.)
The revised Hemi displaces the same 5.7 liters but manages to squeeze more power out while using less fuel.; Variable valve timing and other improvements combine to boost fuel economy by an estimated 5 percent. Power ratings vary by model as listed below. For comparison, current 5.7-liters make between 330 and 345 hp, and between 370 and 390 lb-ft of torque.
Chrysler 300 – 370 hp, 398 lb-ft
Chrysler Aspen – 376 hp, 401 lb-ft
Dodge Challenger – 370 hp, 398 lb-ft automatic; 375 hp, 404 lb-ft manual
Dodge Charger – 370 hp, 398 lb-ft
Dodge Durango – 356 hp, 390 lb-ft
Dodge Ram 1500 – 390 hp, 407 lb-ft
Dodge Ram 2500/3500 – 355 hp, 395 lb-ft
Jeep Commander -; 357 hp, 389 lb-ft
Jeep Grand Cherokee – 357 hp, 389 lb-ft
The new engine is also part of the Dodge Durango Hybrid and Chrysler Aspen Hybrid packages, where it works together with the two-mode transmission’s electric motors to produce 385 hp and 380 lb-ft of torque.
Why haven’t we heard much about this engine yet? Our guess is that Chrysler doesn’t see much reason to hype up an engine that gets a bigger horsepower increase than fuel economy boost. Also, Chrysler likely wants to avoid giving buyers a reason to wait for the improved models so that dealers can sell remaining 2008s.
The first of the new Hemis should be arriving in Challengers now, followed closely by the hybrid SUVs.