MPG gone to sh*t

[hawgs]

last tank i got 13.3 MPG... no time at the track and wasnt driving any harder then i normally drive it. the tank before i got 15.1 MPG. what are some possiblities? its got 40,000 miles have not changed fuel filter ever have run a bottle of STP fuel system cleaner through a month ago...

[Cale]

wow 15 isevenbad
i get like around 20 in my LS1 and I romp on it quite often

[4thGenRS]

Check tire pressure. Low pressure snuck up on me a few times, killing my gas mileage. I make sure all mine are at 30psi and check it monthly now.

This is just one option...

:cool:

[lord_gufi]

15 mpg???? down to 13???? wth?? i get like 32 on the high way an 23 in town!

[Sean37]

Well you need to change the fuel filter for sure. I think it's supposed to be changed every 10K. If the tire pressure is good and the new fuel filter doesn't help then I'd try doing plugs and wires after that.

[Only4U]

as you can see from cale's response, the ls1 is quite efficient. so don't jump all over me for saying that i think the main culprit is in the 17" wheels you ride around in. the bigger the wheel, the more it takes to carry it, hence, worse mpg. the fuel filter is probably not likely because, if the fuel filter were bad, you would be getting more knock problems and/or engine running problems than you would just bad gas mileage. the plugs and wires, not likely either.

[Wicked 3800 V6]

Plugs, wires, fuel filter, 02's, maybe cat, PCV (not a prime concern but it's like $1.50) ... do all of those and see if you still have trouble. EGR is worth mileage too, right?
-Rob

[apiccola]

Check your air filter and change the oil while your at it ... ;)

Maybe consider an alternative fuel. I hear the rice burners prefer a domestic like Uncle Bens.
Personally, I like alcohol. I get all the mileage I need from a bottle of Jack. [img]graemlins/fluffy.gif[/img]

[ December 03, 2002: Message edited by: apiccola ]</p>

[WickEdSix9838]

i got 25.7 on my last tank and i have 3.73's!!

[hawgs]

last tank was 14.01 :D this sucks... glad the semester is over so ill have time to do some maintance

[All_InTheRED]

<blockquote>quote:</font><hr>Originally posted by hawgs:
last tank i got 13.3 MPG... no time at the track and wasnt driving any harder then i normally drive it. the tank before i got 15.1 MPG. what are some possiblities? its got 40,000 miles have not changed fuel filter ever have run a bottle of STP fuel system cleaner through a month ago...<hr></blockquote>


Sounds like my car.

Best highway mileage in 65K miles has been 21mpg.

Usually in town...14-16mpg.

But it runs a whopping 17.8@75mph in the 1/4 mile.

Can't find anything wrong either.