Who is BS'ing who?

There are better way to build engines and produce a great motor that does both h.p and efficiency.

A zero deck engine will always give better mileage,as should a heart shaped combustion chamber.

Alcohol and water injection will raise your gas mileage as well,even on a stock vehicle. I just made a poor mans water/alky injection system that raised my Caravans avg city mileage from 15 mpg to 17.For less than $5 and an hours work.

It's not all in the motor either. You could be having a lot of convertor slippage at lower rpm with a high stall.

Rear gear ratio makes a big difference as well as tire size.