The Alphas will be toughened-up versions of preexisting models, starting off with the big daddy, the Hummer H1 Alpha. A 6.6 liter Duramax turbodiesel will replace the current H1's less powerful ...

There was a time when the Hummer H1 was a vehicle to die for ... namely the 6.6-liter Duramax turbo-diesel engine and the Allison 5-speed automatic transmission. In its native form, the engine ...

Mark your calendars, because we're calling today a watershed moment for the advancement of diesel's acceptance in the U.S. General Motors has just announced a new 4.5L V8 Duramax turbo-diesel ...