Tuesdak
TDR MEMBER
lets face it there is alot more to fuel economy under load than just aerodynamics.
this 35 page booklet from Cummins offers far more more information than anyone on this forum could provide
https://cumminsengines.com/uploads/docs/Secrets of Better Fuel Economy_whitepaper.pdf
Nice find! I wish they would have included AC compressor HP requirements and MPG losses from that. Also the effect on MPG from engine power de-rate due to hotter weather. It's not just the cooling fan killing MPG as I go from 21 MPG without the AC on to 16 MPG with it on. Sadly my tires are not even broken in when the tread is gone! :-laf