Not only is diesel less expensive, but the cars burn a lot less liquid. Using
www.fueleconomy.gov, comparing 3 Automatic VW Jettas from 2006 (I'm using Autos just because most people here drive automatics)
1.9L Diesel: 7.1L/100km
2.0L Turbo (needs premium): 9.4L/100km
2.5L 5 cylinder (runs on regular gas): 10.7L/100km
Take the website, you can set how much you drive annually, and the gas prices in your region as well (Calgarygasprices.com has a lot of them posted). I myself am not sold on the hybrids. I think it's a great idea. Sure electric cars are 'clean' per se, but you plug them into an outlet powered by a petroleum driven power plant, etc. etc. So a hybrid is an electric car with its own efficient specifically built powerplant....BUT diesel has just gone so far with efficiency, it's nuts. Great economy, and as far as diesel being bad for the environment, that's quite a myth. If you're an Andrew Ference about it (not that it's a bad thing, the world needs people like that) I heard somewhere (I'll try to find the official stats) but the average 2000 built diesel vehicle emitted only 2% of the crap that an average 1985 built diesel vehicle did.