haha, well it sure as hell isn't for driving 45 mph, not in colorado at least.

 

seems like a few people who participated in this thread would be better off driving stock civics. trying so hard to get owesome gas milage out of the rotary is not something it was meant to do. though real ways of improving it would be helpful.

 

only plus about automatics... you wont have this debate

 

lol, yeah seriously if you can get good mileage that is great, but if you can't i think that's to be expected!

however there is another aspect of having good, or Mazda-specified, fuel consumption: it can be an indication of a good running engine. or rather more significantly if you AREN'T getting the proper mileage, then you have something that is not right...

 

Yup. 10-12mpg in normal driving is cause for concern. 10-12mpg on, say, a track day or at an autocross, no problems.

However, it *is* possible to get better fuel economy, even when driving hard. It involves getting rid of the stock ECU & putting something better in.

-=Russ=-

 

I just drove about twenty miles at 65mph with the cruise control on. In fourth gear the afr was reading 14.3 and when I tapped the brake pedal and switched to fifth gear and re-engaged the cruise the afr's went to the 15.1 range. This is without the O2 sensor connected and the SAFC having the LOW range adjusted for taking fuel out (not this day but weeks ago). That explains the somewhat lean 15.1 afr in case someone wondered. Fifth gear at 65 is more economical. Who'da thought.

 

I think the varying lowest 5th gear speed for people is speedo accuracy. If I grab 5th at 45 I'd better be going downhill. My speedo also reads ~10 fast. I can usually drive fine at 50 (40) though, so long as there's no big hills. I'd have to agree that 5th sounds more economical at highway speeds (well, the speeds I travel on the highway), but I've also had fuel computers (varying cars, stock and aftermarket) teach me some weird *** things about fuel economy.

 

i always thought 14.7, around stoich, would give you the best fuel efficiency, just wondering if you tuned cruise for even leaner than that?

on one hand leaner means less fuel, but it doesn't do you any good if you aren't burning as efficiently...of course there are many other factors, but unless you are running stratified combustion (that's a whole topic itself) 14.7 is theoretically more effective.

also, anyone tune cruise by EGT? i hear this is the better way to go because you can tell where the burn is most efficient...

 

Best economy is slightly lean of stoich.

-=Russ=-