I've been offered a 1996 518i touring, good price, low miles, nice car. I've always had a 3 series up to now and I have heard that the 4 cyl 1800cc lump is not man enough for the 5. Has anyone any experience of this? I don't want to set any land speed records but equally I don't want the engine to give up after a few miles because it has to work so hard. Also, what kind of mpg could I expect?