[Diesel_Dave]

On my way into work this morning (~40 deg F outside), my truck took 16 miles to get up to full operating temp--and that's with the cab heater off, coolant and oil heaters plugged in all night, insulating blankets on the engine & grille completely blocked off.

What you have to remember is that the more efficient the engine is, the less heat that gets put into the coolant. I was thinking about that this morning...the amount of heat that goes into the coolant is a function of 1) the amount of fuel burned, and 2) the fraction of that fuel energy that goes into the coolant. So let's compare my truck engine to say a Geo Metro. If we both got 40 mpg, then we both burned the same quantity of fuel. Even if the engine efficiency was the same that would mean I put the same number of Btu's in my coolant and the Geo Metro did to his--except I have a whole lot more coolant and cast iron to absorb all that heat. So no wonder it takes so long to warm up. If I were getting 10 mpg I'm sure it would warm up faster because I'd be putting 4 times the amount of energy into the system.

I'm going to try to get at least a front belly pan on here shortly and hopefully that should help somewhat too.