I've helped people out with this topic in the past, but now it's me in need of help I'm basically getting crappy gas mileage for city driving. Last time I filled up I averaged 12.6 mpg. I know that's definately off, because I normally ran 17mpg. Well, only thing I can think that's doing it is my MAF. I put an aftermarket one in. Could that mess anything up? Oh, and another thing, I do get on it everynow and then, but obviously not enough to compensate for that huge drop.

The car is a lightly modded auto. No stall. Nitto tires, front are at 32psi, and the rear DR's are at 30psi.

What could it be?

 

Switch out that MAF and see if thats the prob.

 

Well i've heard that it could be engine buildup, when you change your oil run engine flush through your system then put some good injector cleaner and what not in. There was a post about that earlier a guy put engine flush in an some chemtool in the gastank and gained some pretty darn good gas milage, Thats just what i was thinkin could be a problem?? As for the MAF might be makin your car run a bit too lean causin some extra gas consumption, just another guess

 

I will try the injector cleaner.

Another thing that I thought of, is the fact that I switched to Synthetic a couple weeks back. It was also around the time of the unusual gas consumption.

 

I had the same problem with one of my cars and it was because two fuel injectors were not working.

 

Is there a way for me to test if they're working?

 

It says in the Haynes manual to start your engine, and listen to each injector either using an automotive stethoscope or by placing the tip of a screwdriver against the injector and listening through the handle. You should hear a clicking sound with each injector. Hope this helps and that you find out what's going on!

 

Have you cleaned your throttle body ?? we sell this as a maintenance item. if it does not help with the gas mileage it will help smoothen idle and increase throttle response. I drive my Z in the city as a daily driver and it is mostly stock, I only get 12-15 miles per gallon in the city. BUt she kicks *** on the highway

 

when not being agressive(not babying it, but not smashing it (alot anyway), i get 17-19 mpg(all city) hit 21-23 when mainly highway... but still a good 25-40% city) i never do all interstate...

cory

 

I,ve had that happen a couple times,always avg 17 mpg then all of the sudden I get 12 mpg on a tank,but at the next fill-up it goes back to 17,go figure ! Same gas & gas station,too.But it always has happened in the winter,maybe too long of a warm up in the morning coupled with the oxygenated gas here in the northeast maybe.Check it again at the next tankful & see if it changes

 

When I drove back from Denver in Dec. last year I got 26 mpg overall on a 800 mile trip. The car had original plugs and 101k miles, auto trans. I drove 75-80 most time and couple times for short burst 95 Plus (had to compete with a new thunderbird)
Of course this is stock B4C.
"Ray"

 

That stuff dont work, the chemtool stuff especially, better off just layin off the throttle for a while, or do what i do shift like grandma

 

I get so, so mileage too. Around 16-17 on average but lately I have started to drive like grandma and got 20 mpg which still isn't good considering 80-90% of it was highway use. I just got done installing a vacuum gauge. I now know that my way of driving to save gas could be better.

 

16mpg

 

actually it does. I was the guy who posted on it a couple months ago. let me break it down for you:

BEFORE:
city: 12mpg
highway: 16mpg

AFTER:
city: 17mpg
highway: 22mpg

And it still gets that good. It was an instant gain, and never dropped back off.