thats happened to me a couple of times . LoL I tell them its a 1.3 OH the MPGs must be AWESOME ! .. I go eehhhhh .. no

 

its both. kind of. the engine can be run really lean (at lower loads), its the cat that needs to be rich! the cat can't run lean, and it cant run over 650c, so the stock map is rich. some piston engine cars are like this to varying degrees too.

the rotary also moves a lot of air, and due to the long seals and long strokes (270 degree vs 180 degrees) there is a lot of time and a lot of places for compression leakage

 

my cats gone LOL

 

yes, but the ECU doesn't know that!

 

lol I ahve an after market ECU that I tune myself for hte most part my A/fs will stay between 14.5 amd 15 in my cruising speeds and during light throttle acceleration

 

I average about 22mpg on a not so stock anymore N/A, just have RB cat replacement set and catback, a Jacobs Rotary Pro Pack ignition, Taurus alt, and 3rd gen pump. It's my DD 5 days a weeks for college and don't usually drive any other time, no money, and I usually Granny around my home town, 55mph on the interstate, and usually get in one or two 5-6k runs through 1st and 2nd then a couple miles to cool down before parking at school.

Oh, almost forgot, just pulled air pump and acv yesterday so I don't know how/if that will affect mileage.

 

I've gotten 24 mpg my last two tanks. shifting before 3k rpm and trying to just do more coasting in gear than braking, keeping smooth gear changes, and using 5th gear a lot lol. I think a lot of it comes from patience and looking at your bank account after dumping a few tanks.

 

Wow. City, or highway?

- k -

 

it's about 60% highway and 40% city. mostly country back roads at 55 to 60 mph. then a little ways on the interstate at 70 mph. I removed my airpump and the compressor blew up on the way to work the other day so I cut the belt off. So there is less resistance
on the motor, but I like to think it's just better driving habits and using mid-grade gas
from the same station by my house. Also I drive a '91 vert.

 

I'm impressed. Best I've done is 22 on highway - Interstate - from Montana to Denver. City for me is closer to 16. Hope to do better when repairs and final tuning is done next week.

 

my 23.5MPG figure(330 miles/ 14.25 gallons) was taken at an average speed of 80mph. i could never stomach driving 55mph for a full tank and i never noticed enough of a discrepancy between 55 and 80 to ever attempt it. 4th or 5th also made almost no difference because 4th offers less load but higher revs, 5th is lower revs but higher load and the VE of the rotary is more efficient at higher revs unlike many boingers which are more linear(lugging the engine in higher gears doesn't necessarily net better mileage). non turbo vehicles i could imagine would see an actual difference since 5th is geared a bit higher than my TII, i have never tested our S5 GXL on long trips but i don't believe it ever got over 300miles to a tank and the tank is larger than my S4.

the 55mph figure you see listed many places is a generic rule and doesn't apply to every vehicle. the FC is light and actually very aerodynamic(look at the land speed record holder FC with stock body, it is only lowered but has a full underbody tray. the FD was less stable than the FC at the same speeds) which translates to less drag at higher speeds. if the engine is tuned well at all RPM/load ranges you shouldn't see much difference at higher speeds.

removing the catalyst increases flow in and out of the engine, which actually can increase your mileage(you can also lean out the fuel trims since you do not have to run rich to save the catalyst). i am not advocating removing your cat though, the only vehicle i run catless is my TII because it feels like an 80 year old with arthritis when i put the cat on it(boost is already laggy with the non BB 70 trim turbo and 8.5:1 rotors, with the cat on the power band is so narrow it's almost useless).

 

I think it's a little weird that I get 18 consistantly, driving fast, slow, freeway, city.. Nothing seems to make a difference hahaha

 

Yea, when I brought this S4 GXL out of a 10 year retirement it only got about 12ish. I like to think that everything had to wake up and stretch their pintles, seals, and whatever else that was likely sticking or lagging behind.

Can't wait till I 'Squirt her, grab a TII trans, and 3.9 rear which should almost cancel each other out in terms of running higher/lower rpms at a given speed, but give me something a bit more bullet proof through my hard shifts. Then I'll probably see how high I can get my mileage. This is my DD and I'm a poor college student so it may take a while unfortunately.

 

Highest I've gotten yet was 13, almost all highway, with (3) 1minute auto-x runs. That was NA, and its a S5 HBP engine with 9.4:1 comp. I just got 13.5 with mixed driving after I slapped a 20G kit on it. It's nice not having to downshift to accelerate up slight inclines at 55mph.

 

shift when the light tells you to to get the best fuel milage... its a rx7 dude you wanna play you got to pay