Once again the diesel rumour mill is in full swing. The latest tid-bit of information to come out of the mill is the GM develped 4.5L V8 Duramax diesel engine may be back in the mix. “The 4.5-liter V-8 is fully developed and ready,” said Mark Cieslak, GM’s full-size truck chief engineer. “[If we decided to offer it] we could launch it in a heartbeat.” Some of the origional rumours that were floating about when the motor was first in development was that it was going to be an option for the newly designed Canyon/Colorado quarter ton trucks. That, so far, is not going to happen. If the powerplant is released it would be available as a smaller, more cost effective diesel option in the GMC 1500 pickups and later, possibly as option in the 2500 series trucks.
Performance numbers for the 4.5L Duramax would match the power ratings of the origional 6.6L Duramax released in 2001 at 300 horsepower and 520 pound-feet of torque with an estimated 25% increase in fuel economy versus a comparible gasoline engine. The current 6.6L has a power rating of 397 horses and 765 pound-feet of torque. Price wise, this new Duramax would fall in between the top end gas engine and the top-of-the line 6.6L Duramax.