so my 91na is getting like 18 to the gallon tops if i drive like a granny and in san diego and thats just not possible, so is that about right for a 91's mpg or can i do something to inprove it or fix it?

 

I used to get a easy 20mpg in stop and go driving normal, on longer highway trips I would see 23+

18 is not TERRIBLE, we also have flat roads here, not many hills.
If the car is tuned up, has a good air cleaner, fuel filter, plugs, etc...
and maybe consider a high flow converter and free flowing exaust if you can get away with the smog.
Other then that you aint gonna do that much better.

 

actually 18 is pretty good for a car only rated to 17 on the EPA cycle.

 

+1

my last tank I got 17.66 mpg and there are no hills in Tampa.

 

That's typical in the city. If that includes some freeway, check the FAQ for tips. I tend to get 17 in the city. Lately with infrequent driving, very short trips, and going a little faster I've been getting 15-16.

 

I get atleast 13-15 mpg in the city and on the highway 20mpg, activating the secondary injectors on the highway seriously I think got me into the single digits...
I wasted about 2 gallons going about 10 miles of highway at around 4-5krpm

 

Yeah try to drive it under 3-3.5 thousand ish RPM's to keep the secondaries from kicking in and you'll see a constant 15-20-maybe mpg in the city and 20-25 on the highway. Rotaries like gas... So I drive a smaller lighter RX7 for good mpg sake... a 12A FB!! say hello to 25 mpg pretty much all the time :P

 

That's about what I get on a rebuilt motor with a recent tune up and other misc maintenance.

 

This has also been covered to death. So much so that there are a tonne of links in the FAQ to previous mileage threads.