I was invited by GM to the Milford Proving grounds last week, shaking hands, listening to the new executive management team ... oh and I got to test-drive a 2010 Chevy Express Van with the 2011 Duramax Diesel Engine and Allison Transmission. This next-generation version of the heavy duty V8 has been developed to meet the new Federal US standards for diesel emissions while also giving a lot of additional technological advancement. Specifically, it must reduce the smoggy nitrogen oxide (NOx) levels by 90% from today. It's a clean-air thing, and its a good thing. The Duramax will be produced in two versions. A LML for the Silverado HD truck and a LGH for the Chevy Express van. Both are 6.6 L, with the LML pushing power to a six-speed Allison and the LGH to a GM built six-speed. What's it like to drive? While the engine is not fully fabricated, it was immediately obvious that it was very quiet compared to the current generation Duramax. The RPM level was also much lower, sitting at 600 RPM when at idle. I've asked for an in-depth interview with the GM Diesel engineering cheif, and will report back more on this new engine when that interview is granted!