Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line). A (~) 15 to 20% boost in mpg is offset by the 15 to 20% higher price of the fuel.
Your math isn't totally accurate, and it's just recently that your argument could even be entertained. Even with your faulty math it looks like it's an economic wash. And what type of cars are we talking about comparing?
Only in the last 6 months has diesel cost more than gas. Why is that, it's less refined? (There's the scam!) And they don't add any oxygenate like MTBE. That crap is toxic and is in the flesh of every fish you eat.
Just 2 years ago I was paying $1.65 per gal for diesel and gas was $2.30 +or-. Now diesel here is $3.69 and gas is $3.58. Just filled up with biodiesel at $3.25 over at Austin Biofuels. And I get 45 to 50 MPG. Do the math for me, I'm too lazy.
