General Motors' recent (and vague) announcement of a new V8 diesel has led to significant speculation, especially with regard to power output and packaging size of the engine. As a preemptive strike against doubters, the company recently allowed Diesel Forecast to take a spin in a Buick Rainer equipped with the mystery oil-burner.

For starters, the "light duty" (intended for vehicles with a GVWR of under 8,600 lbs) will produce somewhere in the neighborhood of 330 HP and 520 lb-ft of torque. All that torque comes online around 1800 RPM and extends to 4500 RPM. We feel that these numbers should keep the average driver quite happy (diesel power junkies will just have to wait until aftermarket PCM tuners become available). For this we can credit the wonders of variable-geometry turbocharging, although at this point GM is not saying how many hairdryers they are using (two would be our guess, given the direction in which others are moving).

We were skeptical that a DOHC turbocharged V8 would fit into the same space as GM's ultra-compact pushrod gasoline V8s, but this does indeed appear to be the case (see the above outline drawing from GM, where its outline is shown against the GenIV L92). The fact that it fits under the hood of a GMT360 - a surprisingly tight environment, given the vehicle's external dimensions - speaks to the compact packaging of this engine, and means that we could see it popping up in just about any RWD product from the General.

On the emissions front, GM sees the engine utilizing urea injection with selective catalyst reduction to meet the EPA's 2010 Bin 5 regulations.

[Source: Diesel Forecast]