Originally Posted by C4llyT

Got an older M3, but for those miles a 330D remapped would (obviously) give best mpg, and give the E46 M3 a hard time.
Be best motorway and overtaking car with all that torque.
Bmw are making some of the very best diesel engines lately.
At the least would be 15mpg difference from M3/5 to 330/530D, amount to a pretty penny on that mileage per week.