The demand for the big diesel SUVs that get about 9 miles to a gallon has gone away, and people are trying to sell them for 20% of what they'd bring a year ago.

That sounds... odd. The big diesel SUVs and pickups that get around 9MPG are typically fairly old and used mainly as tow vehicles for businesses or people with large boats, horse trailers, etc. The acquisition cost of a more fuel efficient vehicle that has similar horsepower, torque and towing capacity is far higher than just paying more at the pump.

This isn't passing the smell test. Do you have examples of it happening?

> The demand for the big diesel SUVs that get about 9 miles to a gallon has gone away, and people are trying to sell them for 20% of what they'd bring a year ago.

Any idea what they are replacing them with? Diesel's are pretty fuel-efficient after all, compared to petrol.