Ok, I just did the following service hoping to car will smoother/more efficient:

- new FDP
- new fuel hose recall kit
- RC Engineering serviced injectors
- cleaned fuel rail
- replaced all vacuum hoses
- new plugs, wires

It's a lot of work (at least to me) and now the car runs/boosts much smoother, however, my mpg still suck a$$. Last time I checked, it was 13mpg =(
Now, I don't want to get into all the debates we had in the past about the correct way of calculating mpg and I know this is a beaten to death question but I just thought that the above services would at least give me a few extra mpg. It was 13mpg before, 13mpg after.

check sig for mod...the car is on stock ecu map with no tune...maybe a good tune can help?

 

It really depends on how you drive. I get 12-14MPG city driving when i am on the gas a lot and 20-22MPG cruzing at 65mph. Besides that, you might want to check:

-is the check engine light on? A bad Knock sensor will really lower your MPG
-leaky/old injectors

 

Look....it takes fuel to make hp, no matter how you slice it. There is a direct relationship to the thermal output/btus of a gallon of fuel in any given engine, as far as miles per gallon or liters per seconds or ANY measure you want to make.
My car gets 10 - 12 when driven hard, and about 17 in normal 'combined' driving. Best I've ever seen was somewhere close to 20 mpg, but that was with the old, stock engine.....

 

I might look into replacing the O2 sensor but it was just replaced about 10k miles ago. My car is pretty stock with just the basic bolt ons...
Anyway, I know it's a gas guzzler no matter how you slice it, I guess I was just hoping for better mpg for the work I put in =/

 

If you want a car with good MPG get a prius not an FD =)

 

You are right, you shouldn't complain. You won't get ANY sympathy here!!

 

Drive EXACTLY 55MPH, then you will be happy with your mileage.

 

build a bridge and get over it.

 

RX7s sure aren't built for good MPG.

My RX7 288whp I get about 10mpg.

My turbo civic b18c1 289 whp 26mpg.

Its all good though cuz the rotary is on the way out, V8 on the way in. ...eventually.

 

I dunno. I've never checked my FDs spirited driving only mpg but I get 25mpg at 70-80mph. I got 24 MPG on my last trip from Kennewick to Spokane. Also included in that trip was a 30 to 45 min group drive in the country with a few spirited runs.
The FD is actually the most fuel efficient vehicle I own.lol My Diesel truck gets 17-18 MPG at 70 MPH and the wife's RX-8 A/T gets about 22 mpg at 70-80 MPH.

 

I remedied my MPG problems with an old Honda.

 

Just curious, since I'm not sure about my theory, but it sounds like it could be true. Are you running a single? I figure a single would save more gas at cruising speed since it either wouldn't be in boost, or if it is, the boost pressure wouldn't be as high opposed to a twin seq system.

 

No. I'm still running the original OEM engine and turbos. HP mods are PFC,1200cc secondaries, M2 Med. IC, M2 intake, Pettit DP, and Racing Beat dual tip.

 

Yeah......I did the exact same thing and got the same results. Welcome to the RX-7 owners club.

 

The only things that might have even remotely contributed to improved fuel mileage would be the new plugs and having the injectors serviced. Now, if the old plugs were not that old and the injectors were spraying fine prior to the servicing...then it is not surprising there was no mileage gain realized.

Chalk it all up to the inefficiency of the rotary, I guess. Heck, my twin-turbo Volvo S80 T6 has 272 hp and gets 26 mpg cruising 85 mpg, according to the fuel computer display. And that is a 3500 pound car....

 

Did you change the fuel filter?
Did you change the air filter?
Check your tire pressure.
I would also check to see if you injectors are working properly?
Do you drive like a grandma or a bat outta hell?

My average mpg is around 18. This includes highway and city driving.

 

o2 sensor?