what would cause my 2002 Pontiac grand prix gt 2dr 3.8L to go thru $75 of gas in 1 week only going to work & back home?
5 Answers
Many things can worsen gas milage such as Spark Plugs being bad, Catalytic converter being stopped up, bad gas, the most common would be a sensor malfunction that would make the car run rich. All of these can be tested by just looking at your exhaust while your car is running bad cat will smell bad, plugs will run a darker looking exhaust. So if your exhaust doesn't look or smell right then you can tell its another issue.
How long since your last major tune up? I would also check for possible fuel leaks. Also check your oil. Does is smell like gas? If so could have an injector or injectors sticking open and loosing fuel when vehicle is turned off.
JohnTheCarNut answered 10 years ago
I don't know how far your commute round trip is, or where you live, but cold weather can make a huge difference in mileage, and depending on your region, they reformulate the gas so it has a lower detonation rate thus not as a efficient as gas used in the spring to fall. However, all of the above suggestions are good ones as well. Oh, how many miles if the commute, and do you have traffic to deal with. Also if you have any extra weight you don't need right not, take it out.
its usually zero or below when I start it before I go to work, no smells, no color difference. must be another issue. unsure when it was tuned up, probably hasn't had a tune up since before 2009(since 09 haven't had a decent job lasting longer than 1yr I could save up enough to get a tune up). I think it has to do more with the weather personally. I drive 60mi per day & roughly 300mi per week. I live in Wisconsin. I have 241000mi on the car(going for 300000mi). the only traffic I deal with is between my house & the freeway. there is 10 stoplights from the south end of town where I live & the north end of town where the freeway is, however I bypass 6 stoplights taking a shortcut if I was to go to the north end of town running errands or getting to the freeway otherwise if I drive to the east end depending on how much time I have between when I leave the house & getting to work on time. if I drive to the east end of town to get to the freeway that way there is no shortcut & there is 7 stoplights to get to the east end of town however if you take a different route there is only 3. only weight I have in the car is breakdown essentials & a snow shovel. when the snow goes away(hopefully sooner rather than later) I will remove the snow shovel also. wishfull thinking. another thing I hope to move in june. just finding out right now after working for the first work week I'm only getting $9/hr(trying to find $14/hr not finding it around these parts)& fuel just jumped .05c so, its either I move closer to work or I continue to look for better work. either way $75/wk for fuel is going to add up, $300/mo, $1800/6mo or $3600/yr. this car will be a push pull or drag sale for sure if it doesn't make me go more into poverty than where I'm at.
I also forgot to add one other important thing. Make sure your tires are inflated to the proper pressure. Each 10 degree variation in temperature is a one pound difference in tire pressure. Make sure your pressures are at least up to manufacturers recommended specs. I tend to run pressures 4 to 6 pounds higher in the winter months and check them once a week. Just for interest, check all the tires before you fill them up. You may be surprised at how off they all are. Let me know if there is any difference. Stay warm!