Mitsubishi offers their very nice and very attractive L200 pickup everywhere (australia, england, south america, SE asia) except for the US with an excellent 2.5 turbocharged 4 cylinder diesel, Toyota makes an immortal diesel version of it's HILUX (as seen on TOP GEAR) but it's not a very common version. Isuzu makes an uncommon diesel version of their half ton truck that is sold either under the Isuzu or Chevy badge overseas.
Safetydan: you are completely and utterly wrong about there not being a market for light trucks outside the US, the entire pickup buying world buys light pickup trucks and no other country in the world outside the US and possibly canada has a real market for heavy pickups, just look at every video of 3rd world country traffic, light trucks abound. As was said somewhere, toyota could be a virtual sponsor for jihad, every time you see terrorists or guerillas riding somewhere in a third world country, including iraq right now, they're doing it in a toyota half-ton.
I'm from chile originally, and if you ever go there you'll probably notice that the single most common vehicle on the road is the Chevy luv half ton truck, the government doesn't charge you the 18% sales tax if you buy a pickup for work reasons, and therefore anyone with a legitimate business will buy one, couple to that the fact that diesel is a full dollar less per gallon and you just can't lose
I don't know why but the US has a hate relationship with vehicles with diesel engines, blame the smell of old diesel fuel, the loud engine, lack of acceleration and not least of all the ridiculous fact that diesel is more expensive than gas by around 30 cents a gallon in some places. All the old problems no longer exist, just the higher fuel price.
In the US the half ton pickup is apparently seen as a toy and useless for real work, with virtually the entire fleet of working trucks consisting of the 3/4 or 1 ton full sized pickups. In the US the towing of trailers with pickups is much much more common than in the rest of the world, and for that you would preffer a full sized truck, of course you always can get the optional V10 gasoline engine instead of a diesel.
Europe goes with the diesel powered Combi-vans for fleet work purposes (I dare you to find more than 10 pickups driving around a large german city), the rest of the world with asian or european made true utility trucks.
For the rest of the population in the US, who could use a pickup for non-work reasons, the half tonner is seen as a toy again and the open bed as a liability, so they go instead for an SUV for the occasional hauling of gear. The rest of those who actually WANT a pickup will go with a short bed F150 with a V8 engine or a ram with the 5.7 Hemi.
So where does that leave us? customers in the US want either a big powerful work truck, or a big powerful leisure truck, both of which get horrible gas mileage.
The ranger is one real american light truck, competing with the Toyota, Nissan and Mazda offerings, but having owned one, I wouldn't see why anyone would want a ranger in the first place, they're an awful drive. The Chevy S10 and it's relatives are better trucks, but you don't see many of either in a work role.
with biodiesel becoming more common (I know a guy that runs a diesel truck for 3 bucks a month on it) and cars like the toyota aygo that can get EIGHTY miles a gallon on diesel, I think that cost-concious customers in the US will eventually turn towards diesel powered cars.
So, I'd say the reason no US manufacturer makes a diesel version is because the ppl here won't buy them, either on principle for not being like monster trucks or the percieved higher price of the fuel. In much of the rest of the world it makes sense because diesel is a whole lot cheaper than gas (argentina has a large internal vehicle production capacity and a vast majority of it's cars and trucks are diesel powered). If the government were to reduce taxes on diesel so that it was cheaper than gas, then I predict the pitch would change sharply, and the costs of transportation would also be reduced.
I remember hearing at some point that diesel is actually cheaper to produce than gasoline because it's less refined, is this true? and if it is then doesn't it make a whole lot more sense to produce more diesel than gasoline?