I'm looking into getting a D3 for my daily driver. I do an 80 mile round trip every day to work and back of which 70 miles are motorway and 10 miles are city driving. Although I'd love to go for the 4.2l, I can't help but think the fuel consumption would be horrendous. I drive a BMW 530i at the moment and I barely get 22mpg as it is. So which of the smaller capacity engines are the most reliable and economic? Although I swore I'd never drive a diesel I might make an exception here. Also, do they suffer from any major problems I should be looking out for when buying one?