kahren told me about this, ive verified it. i put 800miles on an rx8 getting 20mpg, which isnt great, seems like its better than most. the key is to keep the cruising rpms under 3750. at 3750 it goes from running 2 injectors at a lean mixture, to all 6 injectors and rich. rich is bad for mileage.



so keep it under 3750, and your mileage will get much better. happy thing is this only applies to cruising, you can still accelerate like you want, but if you're just going a constant speed, keep it under 3700

 

how rich does it go? maybe time for a afc?

 

is that the rpm the secondary ports open on that motor?

 

i would assume, that's pretty close to the 13b na, isnt it 3800

 

yeah the aux ports open somewhere around that time. i dunno, be nice if the other injectors waited a bit longer to turn on, or they turned on but it still stayed in closed loop or something, 3700 is like 75mph....

 

I got an average of 23mpg in my fd keeping it in 5th and trying not to exceed 25% duty cycle ( pfc commander ) that was on a 600km trip mostly on open roads but quite hilly. Also mantaining 100- 115 kph.

 

It just came to me . about 14 years ago i did a milage test in my rx3. It had a 13b stage2 ( a good street port) std diff s1 rx7 gearbox a std 12a 4 barrel with weld secondaries . i got 38mpg nursing it but driving the speed limit. On a retry with a lead foot 16mpg. Power is not free. Rotaries can be economical.

 

yep, my fd got 23mpg on the freeway too, keep it under 3200....



the 20b got 19.9 on the way to sevenstock 6, i was happy with that

 

Man, is hard to keep the car underthat RPM. it just wants to go, even on 6th.

 

yeah i know its like a gsl-se that way