Lack of boost leaks will be helping; turbo not working as hard etc
Dont forget the rise in ambient temperature too
Don't say the RISE in temperature has helped? I thought cold air was better for MPG!?
You ever noticed how it drops during the winter??
Dont forget that diesels are horribly inefficient when they are cold
Cold air is better for POWER; why did you fit a larger intercooler?? To keep temps down and to reduce heatsoak
You got the 150?? Standard intercooler is surprisingly efficient