Charlie Self wrote:

FWIW, Toyota is playing with a large dually diesel now:

http://www.theautochannel.com/news/2007/11/05/069676.html

It's got an 8.0 litre, inline-six turbo diesel. G

Got to drive the then new Tundra in September of '06 at a press
conference. That one was immense, had the immense gas V8, and the
power was almost frightening. No quality comments apply, as the
interior trim and other bits were not yet set, but it pulled like a
train. They did announce, in response to questions, that a diesel
would be forthcoming in a year or two, but gave no details at all.

When General Motors divorced Isuzu recently, Toyota stepped in a bought
a minority interest in Isuzu. Isuzu is the source of GM's Duramax truck
diesel engines. Dodge gets it's from Cummins and Ford's is from
Navistar. So you see, the US truck makers only look like they have an
edge in diesel powered trucks. In reality the engines are bought from
third parties and are available in any interested enough maker.