BooRadley

Well, I am using it, but I guess the fact that I'm interviewing with Toyota and several Tier 1 automotive company suppliers isn't using my degree, as I currently haven't accepted a job yet.
The amount of ricers that are 16 year old kids on any automotive board is obnoxious, and I've heard every nonsensical argument in the book and am frankly tired of arguing every point into the ground for the sake of spreading correct information. So , I throw out my "BS" qualifications to give myself more inital credibility. As for you Sochiro Honda comment, I've had to listen to plenty of people tell me in real life about cars and have felt like Sochiro Honda in that case. Sorry if I got a little quick with you, but I can't screen out the ricers, and for every knowledagble person there is on the internet, there are 100 bullshiters. Please accept my apology and lets not get into a flamewar.

And , to prove that I don't have a bunch of BS qualifications, I'll attempt to prove my point.

First of all, we need to choose how we define "rotary MPG". Lets generalize it to engine only and compare it to a similar displacement, naturally aspirated internal combustion engine. The weight will be approximately the same either way, and the RX7 was a very aerodynamic and lightweight car, so the chassis got better efficency than most other cars.

The rotary engine is a normal spark-combustion engine. It has a different configuration than the normal piston engine, but it still is a 4-cycle spark ignition engine. Classic thermodynamics states that a 4-cycle engine gains maximum theoretical efficency at the following conditions: (assuming everything else, including internal friction, remains constant and the only variable is compression ratio) :
Efficency goes up as compression ratio goes up.

The graph is roughly linear with the % efficency ( total work out, from combustion/ amount of work put into system, thereotical maximum )

Now, the classic( Pre RX-8) rotary engines had a very low compression ratio simply from the apex seal not being able to seal completely on the strokes ... a compression ratio figure around 6.5:1. In order to counteract this, engineers added turbos to boost the efficency of the engine and bump the compression ratio up to an effective 9.5:1 in stock form (with a perfect seal, it would be much higher but some of the compressed air is just going to go straight past the seal and into the exhaust, a characteristic sound of RX7s) , but in doing so , turbos take power away from the engine to compress air. If you compared a naturally aspirated engine of the exact same compression ratio, the Turbo Rotary would be burning more fuel but producing more horsepower at the same time because of the added effect of the turbos. The internal friction is slightly less in a rotary, but the lower initial compression ratio makes the overall efficency less because of the required turbos. Without turbos, the old generation rotary would be inefficent and not a good performer. On these old cars, the seal didn't age gracefully and became gradually worse over the years , making a relatively short engine life.

Now, the new rotaries... the RX8... supossedly has been extensively reengineered for optimum performancel ( I haven't looked much into it) and should have alot better economy and power because it holds its compression ratio better and doesn't require turbos (which do take power, despite what anyone says, how else are you going to compress air?).

Moon, I hope this illustrates my point. My sources are the Bosch Automotive handbook and Fundamentals of Engineering Thermodynamics by Moran and Shapiro. Feel free to ask any questions.