We spent summer before last driving around France and Italy in a rented turbo diesel powered Peugot. I think it was a 307. Anyway it was the size of a Toyota Corolla.
The better mileage plus the lower price of diesel took a good bit of the pain out of paying those high European fuel prices.
I worked it out a couple of times and the cost wasn't that much higher than driving a gas hog here.
The Peugot wasn't much of a car though.