Actually, I can see no reason why a 4-cyl turbodiesel couldn’t provide more than adequate performance in a light duty truck. Even many full-size heavy duty trucks only have a 6-cyl of 5 litres or so displacement.
Many of the truck makers are scrambling to make diesels for their 1500-class trucks now. GM has a 4.5L TD that should be out soon.
We *should* be seeing more diesels on the road shortly.
Gotta say I’ve certainly been surprised by the performance of some of my 4-cyl imports... None of them has been anything that’d burn the rubber off the rims, mind you, but they’ve been adequate and comfortable as daily drivers for me, I guess, if vastly underpowered (but I always want more power!).
I just think there are a significant number of guys out there who wouldn’t be caught dead driving around in a big 4-banger pickup, and it’s gonna take one hell of a sales campaign to flip ‘em. In fact, that may be one of the main reasons Toyota and Nissan, for example, have gone to the V8 for their full-size pickups, instead of going the 4-cyl turbodiesel route.