I have a stock 86 N/A and have been doing mostly interstate driving with an average gas mileage of about 12 MPG. I bought the car hoping the small car would get better gas mileage than my '78 pickup but it appears I was wrong. Is there anything that could be broken that could cause this?

I get almost 20mpg with my convertible, mostly highway driving, but with enough racing and 120mph runs sprinkled in to make it fun. I expect there is something wrong with your car.

i agree, you should be getting more mileage than that....but if what you were intersted in was fuel mileage, why did you pick a sports car?

02 sensor

i have this problem, its probably your primary injectors. either clean then or just replace them. you can find new ones at any rx7 shop webpage. if you need more help send me a message. cheers!

either that or u could just be running rich. but that would affect alot more than ur gas mileage and its alot more dangerous to just go in and change. if you lean it out, it will perform better, accelerate better, get better gas milage, etc.. But, if you lean it out too much, it will go pop. goodluck man, hopefully just changing the old injectors will fix it.

coolant temp sensor?

foot?

Have you done the routine maintenance stuff, like clean the injectors, replace the fuel filter, plugs, and O2 sensor, and the transmission and differential fluids? Also check your timing. That has a big effect on highway mileage.

I would often leave my car in 4th on the highway just because 5th is so disgustingly tall, whenever I did this fuel mileage went to ****.



do you take advantage of the overdrive 5th gear when you're cruising on the highway?

12 MPG in a stock N/A means 2 things:

1- can't calculate MPG,

2- engine needs work (tune-up), running rich can cause mileage to go down, but not from the normall 22 highway to 12 https://www.nopistons.com/forums/pub...closedeyes.gif

When I bought my car I was looking for 18-25 MPG. The only things I have done to the car are replace the plugs, some of the fluids, and put on a cone filter. I use 5th gear and dont race much so that isnt it. Ill try the injectors and the O2 sensor and see if that helps. Thanks.

Andy

are there any drivability issues with the car you have not mentioned which might help us suggest possible problems? run rough when cold, hesitations, lack of power, smoke from exhaust, anything?

For what its worth, I was getting around 22 mpg highway when i had just a cone filter. After full exhaust and a few other mods, it went into the 25-28 mpg range.

It wont restart about 15 mins after I shut it off. (I think thats flooding) That might be evidence that its the injectors.

It also gives out a small white puff of smoke when I start it. I know that there is a very small leak in the coolant seal, causing it to slowly lose coolant. Im planning on rebuilding the engine next summer to fix that.

Also there is a very slight hesitation around 3500-3800 RPM if it isnt fully warm yet. I dont notice any hesitation after 3-4 miles.

Other than these things the engine runs pretty good, not really powerful but its better than my old truck. Hope this helps.

fix those issues and I bet you your mpg will magically go up. First thing imo would be new injectors or have them cleaned, they sound like they are leaking.

Clogged cats possibly?