[JSH]

Originally Posted by racprops

People, I am very much into improving MPG, sadly at best is seems a LOT of work gives little improvement in air drag, and to really get results one needs a wind tunnel big enough to test your car/truck as models do not always react as does real cars in the real world does.

The number are at best 30% improvement, so on a car that gets 32MPG you can only get 9.6 more MPG or 41.6….and ONLY if you get everything 100% correct.

I think you really want to work on engine, fuel systems, and drive line…

Here is a real mind blower, the 2017 Chevy Express 2500 VAN (full size) with a 2.8 Turbo Diesel running a 8 peed auto is RATED at 30MPG at highway.

A stock BOX getting 30MPG….

Rich

I'm curious where you found a rating on the 2.8L diesel. All the window stickers I've looked at don't give a EPA MPG rating.