One Thirsty J!

[R4v3n]

Well this past week has been pretty cold and crappy outside here in Chicago. Last night I went to fill up my car with gas. Usually I reset my tripometer and then take that mileage number and divide that by the number of gallons I fill up. Well this time around the number I got was pretty shocking. 13.5 miles per gallon! I know the J is one thirsty little car and it is pretty crappy out, but thats rediculous. Am I right to believe there is a problem here? And if so, any suggestions? Should I get my fuel delivery system checked out (injectors, fuel rail, etc.)?

[R4v3n]

Oh, and in the summer I was averaging around 20 mpg and up. That's why I'm soo concearned about this low figure. Also, it appears to get progressively worse. The week before, I filled up and got about 15.

[PalmerWMD]

Exessively loss of milage is most often traced to a faulty MAF or MAF connector.

However, winter gas drives up consumption ,combine this with perhaps more idling in winter to warm up+defrost and this could be an alternative explanation.

Fred..

PS: My Q currently gets 13 mpg under curernt conditons and is in tiptop shape.

[R4v3n]

Thanks for the quick response. True, the weather is pretty rough on the car, but I just see this as a pretty drastic change. I wouldn't mind it so much if she didn't just take premium. I understand the Q getting such crappy mileage, packing the big bad V8 and all, hehe.

As for the MAF, any quick way to test or check it out? It wouldn't kill me to pay for someone to look at it and/or replace it, but still...

[elwesso]

My Q gets about 13 on 93, 14ish on 89 (bad KS, going full premium with new KS)...

Best way to test the MAF is to wiggle the connector.... maybe thats for bad idle....

Doing donuts doesnt help your mileage either!!!!

[VimyJ]

13.5 is pretty darn bad. I've noticed my mileage slipping at little to though but its not down there. Still over 20. Several things about cold can effect mileage though: Car idles higher longer, TC takes longer to kick in until the ATF is warm, rubber tires don't roll as well. If you're taking short trips then these factors will definitely come into play.

Might be possible that you have a faulty sensor that is constanly sending a cold signal to the ECU and making your car run rich. A bad thermostat can cause that and I'm sure there are others.

[diamondj30]

i get 20 with 436 gears