i searched........

this is not a poor MPG thread.

All I want to know is: at what RPM are you running at say 70-75 MPH on cruise?

I'm running around 4000 RPM is this normal?

Thanks in advance for your positive input! :)

Yes.

Yup, perfectly normal.

In fact, I rarely look at the speed when I'm driving on the freeway...if I look down at see 4,000 rpm, I pretty much know how fast I'm going.

thanks alot guys! i was just curious due to the fact that this is definately my first rotary and my first manual!! I notice that most other cars, and I know that this car is not just another car, run at around 2000 at cruising speed. thanks for the input

FYI as an aside. Apparenetly you get more MPG is you cruise under 3750rpm, which is right before the first set of fuel injectors open. Something to note if your in a position where you want to ring the MPG for all you can get..

just checked my mileage today when i filled up... just a hair over 17 with mixed city/hwy..... i can deal with that!

Wow, that 6th gear isn't being put to good use. I thought 3200rpm @ 70mph was bad.

sstricker:

Yeah, the 4,000 might seem a bit high compared to normal piston engines but you have to keep in mind how different our rotary engines are.

A piston engine would not like cruising at that rpm range but most piston engines have a MUCH lower redline. (5k, maybe 6K)
Don't think of it as 4,000 but where is it in relationship to the redline...you've still got 5,500 rpms to go. :)

Yeah but an overdrive gear should provide low rpms for highway driving. 3k would not be bad...even a hair under. Remember, you can always downshift if you need to pass.

Look at it this way. 3k rpm cruise with a 5k rpm redline means you're using three fifths of your available rpms to cruise. That's a ratio of 0.6. 4k rpm with a 9k redline is four ninths, or .44.

So comparatively, our cruising revs are lower than those of your normal piston engine.

Per your math I have a cruise rpm at 3k with a 6500rpm redline. That is .46. Not to get this topic off subject terribly.

My sister has a new Acura RSX type-S, 2.0 L with a six-speed trans. The redline is 8100 rpm and the 70 mph cruise is at about 3,650 rpm so its nearly the same as the RX-8. smaller displacement needs the gearing to keep the zip in it. I cruise at 68-70 mpg to keep below the 3750 rpm point and stay on the primary injectors, that gets the best gas milage for me on the hwy, about 23 mpg average (all hwy).

Great,
Jeff B. ;)

Not to turn this into an mpgs thread... I have tested the 3750 rpm myth and have no belief in any validity. I find less than .5mpg difference cruising at 70 or 80. Even ran a full tank without ever shifting past 5th gear just to run the rpms up like cruising at 90 and no effect.