Atrocious gas mileage

[SaturdaysGS]

So I've noticed a pretty decent decline in gas mileage, that seems consistent whether I drive like a granny or boy racer. I don't usually keep track of my mpg, and dont much trust the DIC, but I did run it pretty damn close to empty (filled up 15.1 gallons) and reset the trip computer. Did my usual commute which is mostly stop and go, but still has some decent cruising. Last year I was getting 230 miles to a tank on this very commute, which isnt all that great, and now I checked the trip computer to see 183 miles. Low Fuel was on for about 5 miles as well. W.T.F.

Obviously I have issues. I'm taking a list of things I should replace/clean etc.

-O2 Sensor, though its not that old, it can't hurt.
-Plugs, havent changed them in 30k, cant even remember the last ones I put in, I believe NGK's
-Replace K&N filter, looks like shit
-Clean MAF w/MAF cleaner

Anything else I'm missing?

FWIW my "mods" are
-stock pulley (press on 3.5 around here somewhere)
-paceshitters w/cat (leaky)
-intake
-EGR disabled (IIRC)

Click to read more...

 

[Mook]

winter gas can contribute

 

[Yaj Yak]

my car is getting dogshit gas mileage as of about 2-3 weeks ago as well... from 21-22... to 15 now.

i think my 103's and 160 thermostat and freezing temps arent helping

 

[SaturdaysGS]

winter gas can contribute

true, but it seems to have been like this over the summer as well. (I'm really BIG on procrastinating)

I have a 180* thermo aswell, but the car heats up plenty quick.

 

[Riski]

22mpg here....

 

[ShadyNinja]

maybe a good fuel system cleaner will help?
http://www.thechicagogarage.org/forum/showthread.php?t=38335

I have a case here , Orland park is not too far from Joliet...

and if you decide to ditch that oily k&n and want to try a dry filter that flows as well, but filters much better ,let me know.

 

[Eagle]

I noticed mine going down a bit lately too. Getting 18-20mpg around town, but still getting 28mpg+ on longer highway trips!

 

[Runtz52]

i havent really noticed a decline, got 25 mpg in my lumi on my michigan trip, and most of the time i was doin 70 plus

 

[Bob Kazamakis]

Mine went up from 22mpg to 24mpg

 

[SaturdaysGS]

My highway mileage aint to great either.. I'll have to go on a trip to see where I'm at with that. This car is so rediculous.

Shady, I'll have to swing by and get a dry filter and pick up some of that fuel system cleaner. I've been putting off getting one, but I really need work on getting this car healthy again.

 

[Turbocharged400sbc]

deffinatly clean yer maf sensors with rubbing alcohol and a few q tips with 90% of the cotton ripped off

if your filters that bad wait till ya see what comes off the maf filaments

 

[Yaj Yak]

thats a goooodidear

 

[ShadyNinja]

My highway mileage aint to great either.. I'll have to go on a trip to see where I'm at with that. This car is so rediculous.

Shady, I'll have to swing by and get a dry filter and pick up some of that fuel system cleaner. I've been putting off getting one, but I really need work on getting this car healthy again.

lemmie know,
measure the one you have now...
https://www.amsoil.com/products/ea_filters/EaAU_Features.pdf

 

[Mike K]

That's definitely off. Even with the turbo and aggressive driving I get 270 miles out of a tank and if there's highway mixed in with the, 300+ easily.

You're off somewhere. Do you get a lot of black smoke when you get on it? It sounds like you're running pig rich if mileage is that bad.

 

[Outlaw]

mine went down from about 230mi to about 210mi out of a tank in my blazer... tank takes about 15 gallons normally, 16 if i really push it.

 

[TonzKnock-G]

That's one thing I don't miss about that car. Horrible winter gas mileage. No better than my G8 with dod disabled. Although I'm going to enable it for the winter.

 

[10sec]

I'll bet the plugs are fouled, maf is dirty, o2 is covered with shit, and the filter is junk. I got better mpg's than that with E85 and letting the car warm up 10 min everyday before i drove it. EEEK that's horrible.

 

[EmersonHart13]

That is quite terrible.... I bet you haven't changed your oil in 6 months either? lol kidding...

 

[SaturdaysGS]

No black smoke, and I do change the oil regularly, thanks JOHN!

Cleaned the MAF a little today, it was dirty. Gonna tear it down a little more and clean it better, just wanted to see what I could get in 5 minutes at work.

P.S. I just realized the car feels faster under part throttle (3/4) than full throttle. 1-2 is better too.