I have already kind of made a post about this but this time I'm seriously worried something is wrong with my car. I filled it up with 93 octane (14 gallons, tank wasn't 100% empty) and 77 miles later, I'm halfway through my fuel. I don't drive it like it was stolen, or anything other than a few seconds of gunning it, but this isn't normal. Last thread a lot of you said tune up which I haven't gotten around to, and ecu reset, which I did. But at this point I'm wondering if getting this bad gas mileage could be something worse, and possibly more specific. Any help is HIGHLY appreciated.

 

Is your car a mt or at? To lazy to find your old post.

 

Did you check your tire pressure, clean your MAF sensor or run a can of Chevron Techron through your gas tank like I suggested in your other thread?

You really should do the full tuneup though if you want to go at the problem head on rather than dancing around with side issues.

 

Find out your miles per gallon and then we'll be able to help you

 

it is an at

 

doesnt 77 miles for halfway of fuel sound like a desperate cry for help?

 

Believe me a tune up is next on my list, but believe it or not, I don't have the time to take it somewhere to get it done, much less do it myself.

 

To my understanding, you filled up a full tank "14gallon" of 93 octan. Now your gas gauge is saying half and your trip gauge which you reset after your full tank was filled is saying 77mile?

I would consister you go and fill your tank to full with 93 octan again and check how many gallon. Just to see your gas gauge is working correctly.

 

No way in hell any problem associated with a simple tune-up would result in your vehicle burning 7 +/- gallons of fuel in 77 miles. That's approximatley 10 miles per gallon. You'd have to be running with an intake completley blocked off, 10psi of air pressure in your tires, and spark plugs that haven't been changed in 100k miles to get that bad of MPGs. The problem is definetly something else....first guess being the gauge itself. Second guess being a ecu problem where you're running super rich. Third guess being a leak in your gas tank. Does your car smell wierd?

 

My car smells fine. It has 72k miles, but the spark plugs have probably never been changed. I reset my ECU. I'm seriously desperate and as soon as I get some time I'm taking it to either a mechanic or a dealership to see what's up, and get it tuned up either way. But I am not about to drop 300 a month on gas for a car that although a sport coupe, does not get 11 mpg. That's insane.

 

Correct. I don't know if you read my last thread but I filled it up for the 1st time with 17 gallons, regular gas, and got 200-something miles out of it.. which is also pretty bad.

 

Go fill it up again and see how many gallons it takes and divide your mileage by that. Never rely on the gauge, especially the ones in these cars.


Nevermind. Saw your latest post just now.

 

This is the second time I fill it up. The first time I still got pretty crappy mpg, 200- something out of a 17 gallon fill

 

One important question.. how many gallons max does it take to fill up? The highest it's taken so far has been 17, which may be why I'm getting crappy mpg, unless what I'm thinking in my head doesn't make sense. if 17 gallons is enough to make the fuel gauge go up to F, but it takes more, than I would get more miles while still seeing that F... does that make sense?

 

No 17 is about right between empty and full. Its a 20 gallon tank.