From my understanding, further developing hybrids looks to be ahead in
priority to optimizing diesels in the industry. SAE does a yearly survey
right before the world congress, and it was something like 38% of
respondents(all tier 1 supply company engineers or engineers for automakers)
said hybrid development was the #1 powertrain systems effort over the next
ten years, optimizing diesels was something like 24%.  This of course
doesn't mean that will happen or is true, but everything certainly seems to
coincide right now.

It makes sense that Japanese automakers would be pursuing hybrids just
because for one thing, they  started it, but also because of the nature of
their markets. Gas hybrids make good sense for lot's of stop and go(read any
type of driving in japan) and city driving here, but more importantly diesel
optimization is still behind in terms of profitability.. and since cost
reduction is the single largest priority for automakers in 07, followed by
emissions, then fuel econ and CAF� requirements. It seems like the biggest
reason we aren't seeing the light duty diesels is they are still too
expensive. If they get further in development of clean diesels that don't
need active NOX reduction to meet Tier 2 bin 5, then it's possible... for
now things like the bluetec diesels are going to be available and the ones
to watch, but they need "adblue" which should be "adpiss" because it's a
tank of urea used for the SCR catalyst needed to meet tier 2 bin 5... most
people don't want an extra tank of urea in their car simply because it's
expensive for OEMs to put it there... especially if the vehicle is expensive
to begin with.. maybe they will have a way to integrate a urinal/filter so
you never have to find urea to add to you're bluetec. In any case, the
exhaust system is very expensive, complicated, and without it the whole thng
is a no-go.. so not a great outcome at the moment.

There are a number of light-medium duty cab-over diesel hybrid trucks that
have been selling in Japan since the early 2000's, fuso, hino, and Nissan
all have some variation.. but they are still only suited for heavy vehicles,
and are still expensive. The biggest reason they sell at all is mostly from
a sense of either social responsibility or corporate loyalty in Japan, they
still don't make economic sense for companies that buy them, and we all know
how well that kind of non-money motivated idea works here. Individuals
sometimes(prius, civc hv, etc), companies no way, not until the money is
there.

Jim Akiba