my car has a 2.5in revtek suspension lift and 31x10.5 Thornbirds(I know these are hurting my gas mileage), but im getting about 12-13mpg. I havent gotten 14mpg yet since i've owned the truck. any ideas about what i can do? by the way. for some reason. my gas needle is on the "E" and the low gas light comes on. I'll fill it up, and it only takes about 14 gallons at that point. arent these ~18 gallon tanks? I know theres some gas still in the tank, but 4 gallons seems like alot for the gas light to still come on

 

geez 14mpg i get atleast 21 mpg not sure it thats do to the fact i have a 5spd i would first get some different tires

 

I guess it's something we have to live with. Have any aftermarket air systems installed? Deckplated? Exhaust? Headers? They will help somewhat. Search first, I'm sure this has been covered before. BTW how do you like those thornbirds?

 

How 'bout a tune up? I'd replace the o2 sensor too. You should be getting at least 17mpg.

 

try a new 02 sensor and fuel filter with a tune up did wonders for mine

 

elton. I've NEVER gotten over 13.5mpg, i'd be satisfied with 14 at this point
cleansr5. Everything is stock as far as I know, but I did buy a deckplate, I just need to get it installed, the Thornbirds ride like crap on the road. but they look damn good.

chickenlover/ohareleyman. all that i've done to the car is changed the spark plugs. and chickenlover do you think i should be getting 17mpg even w these tires? by the way. w this lift. Do I need to change the gears or anything?

thanks for the help guys.

 

i bet those tires are heavy and not to sure if the steel wheels are helping

 

Your tire and wheel combo are definitely hurting your milage but I would try a tune-up and a new O2 sensor before you get new tires.

 

Not sure what size tires you had before and if it has been regeared or not. But, assuming the tires are taller than stock, you are getting a few things working against MPG. First, you are driving farther than your odometer indicates. How much farther? Simple math: (new-tire-diameter / stock-tire-diameter) gives you the answer, so if stock was say 30" and you now have 33" tires, you have 10% taller tires than stock and are driving 10% farther than the odometer registers. On top of that, you are also driving 10% faster than the speedometer indicates, faster speed = more air drag = lower MPG. And to top if off, the engine is working 10% harder than before and that also lowers MPG.

 

Very well stated. In other words, go skinnier if you want better mileage.

 

Here's a quick tool I use:
http://www.miata.net/garage/tirecalc.html

As for boosting your MPG -- anything to open up your engine to breathe will reduce its need for fuel. I.e. the more air you can supply the less gas you will use. To that end, Cold Air Intakes work well and are relatively cheap. Anytime you can get exhaust out quicker, you can get more air in -- so exhaust systems also give you a minor increase in gas mileage...A clean fuel filter and clean fuel injectors can also help out. If anything, just replace your airfilter with a higher flowing filter -- should at least get you 1 or 2 mpg...

As for your fuel light issue -- sounds like your fuel sending unit is going...

 

Unless you plan on keeping it forever, don't start bolting on aftermarket parts to increase your MPG. Even if you get 1-3 more MPG it will take forever just to recoup the money spent on the aftermarket parts if ever.

On the other hand if you want to go faster and can live with extra MPG being a side order go right on ahead.

 

i always fine a handful of thumb tacks in the right shoe just before you set off works wonders for MPG