Originally Posted by
contango
I don't quite get why diesel isn't bigger in the US. I realise it's more expensive than regular gas but based on cars in the UK it's worth paying the extra for the fuel economy.Here something like a Toyota RAV4 with a petrol engine gets about 20-25mpg but the same car with a diesel engine gets more like 40-45mpg. (Our gallons are bigger than US gallons so the numbers you guys over the water see might be lower, but the ratio between them should be comparable).
.
The answer may be simpler than you might expect. Particulates produced by diesel are greater than those produced by gas vehicles. At least in all states that ascribe to California CARB standards Diesel has to be as clean as a relatively dirty car and many new cars have now reached a standard called PZERO. To clean diesels enough to come close to these standards they have to add particulate traps and here comes catch 22. If the particulate trap is required to meet smog standards it must have a warrantee of 100,000 miles before servicing. To meet these standards diesels cost a lot more than a small compact car and the fuel itself cost more than gas. To make up the difference takes longer than the average American keeps a car. Diesel trucks and SUVs are pretty popular however because they have a smog exemption at 2/4 ton or better.
The short answer is Government standards and air quality combine to make life hard on diesel in the US.
Or so I have read but I have owned a diesel truck.