Air filter mileage

[rockfangd]

hi everyone. I have been checking and recording my mileage for the past month and i do not like the results. I have been averaging 237 miles to a tank of gas (16.94 including filler tube) which equals 14.8 mpg. which is mix between highway and city driving. I was wondering if the cone air filter could be making a difference. The car runs perfect. not even a sputter. Even at 90 on the highway it drives perfectly straight. I have always used mid grade in the car since i bought it 5 years ago. The exhaust burns clean. I have done fuel injection service, seafoam, completely cleaned the TB, new TPS, IAC, plugs, wires, coil packs. You name it it is new lol. Thanks for all of the insight. I do love the sound the air intake makes. And i do feel more power on takeoff with it.

[Addicted To Boost]

Seriously? :eek: I get 22 MPG with 100% city driving in my TGP. I think you have another problem somewhere man.

[rockfangd]

see thats what i was thinking. The TCC locks in fine when i am on the highway and at steady speed doing 40-45 i am at 1350-1480 rpm, at 55-60 i am at about 2100-2300. Usually i drive reasonable, unless of course i am very stressed or angry but i try to limit that. I cant seem to figure it out. I even replaced the Egr last year. I know i have no vacumn leaks

[19Cutlass94]

I get more mileage in my new motor!



Try this, go WOT to clean it out, or check the port from the EGR to the back of the TB, that OFTEN gets clogged/part clogged with carbon.

[rockfangd]

lol ask bigjoeford how i open up my car lol. he knows top hand how i do it. I open it up pretty good sometimes when i get on the highway. Any way you could possibly post a pic of that port. I have heard of that but i have never cleaned it before. I just want to make sure i clean the right part :mrgreen:

[bigjoeford]

lol ask bigjoeford how i open up my car lol. he knows top hand how i do it. I open it up pretty good sometimes when i get on the highway. Any way you could possibly post a pic of that port. I have heard of that but i have never cleaned it before. I just want to make sure i clean the right part :mrgreen:


Oh he know how to open these cars up to the max. I almost shit myslef when i left him drive mine on a seafoam run  :willynilly:

[89SupremeCutty]

im not sure how big the tank is on my car but im getting very close to 400 miles per tank. and the best part is that im not sure when the last time a tune up and fuel filter was done to the car. i changed the air filter when i bought it back in august but that was about it.

[1990lumina]

You replace the O2 sensor as well?

[rockfangd]

yes. I put one in in october of last year, and i changed the fuel filter twice in the last year

[Robby1870]

you turn 2100-2300rpms at 55-60mph in overdrive with the T/C locked up?

[AWeb80]

seafoam it.....

[MikeP2389]

george did u put a bosch o2 in? if so that might be the problem there.

[rockfangd]

you turn 2100-2300rpms at 55-60mph in overdrive with the T/C locked up?

i am not wuite sure if the tcc locks up right away but that is usually close.

seafoam it.....


I did seafoam it :mrgreen:

george did u put a bosch o2 in? if so that might be the problem there.
yes i made a big mistake of putting in a bosch, and it was a very large PITA to do :evil:

[Robby1870]

With the T/C locked up in overdrive you should be around 2100rpms at 70mph, unless you have a different final drive ratio than stock.

[AWeb80]

Bosch O2's Suck. I Had One In Bad On The Gp In 2K Miles. Stay Away From Bosch Anything On Our Cars.

[notsoslimshady76]

Yeah I have a bosch right now, and I think my mileage has gone down from it lol

[xtremerevolution]

Wow....that's pretty bad.

I get 23 mpg on my 3.8 Regal (L27) city/highway mixed, and the 4.6L Northstar Bonneville gets 19.5 MPG mixed, so there's definitely something wrong.

However, I wouldn't be pulling 90 on the highway. I'm sure that has quite an effect on your gas mileage, lol.

[rockfangd]

that i cant help. when i drive it it drives me lol. it is so smooth i cant even tell how fast i am going. thank god for the hud otherwise i would get a ticket lol. i think of it as the faster i go the less time the car is running lol :mrgreen:

[xtremerevolution]

that i cant help. when i drive it it drives me lol. it is so smooth i cant even tell how fast i am going. thank god for the hud otherwise i would get a ticket lol. i think of it as the faster i go the less time the car is running lol :mrgreen:


Yeah that makes sense in some ways. Try thinking of it as the faster you go the more gas you use per mile of "going."

[rockfangd]

yeah i know sadly that is true. i dont think that could make that much of a difference though

[19Cutlass94]

Change that o2 sensor. The AC does cost more, but its well worth it.

[xtremerevolution]

yeah i know sadly that is true. i dont think that could make that much of a difference though


You'd be surprised. I knew a guy with a 3.1 Cutlass convertible who was pulling 12 MPG. Granted, he had 20's on, but he also liked to pull 90 on the highway...

[rockfangd]

someone said something about cleaning the egr tube. Can someone possibly post a picture of what i have to remove to clean it. Thanks

[AWeb80]

it is a passage molded into the inside of the plenum.....behind the TB.

it goes from where the EGR sits and exits right behind the TB in the plenum neck.

take the EGR off and TB off, then run a coat hanger back and forth in the passage and break that stuff loose. Then try a pipe cleaner to brush it out

[19Cutlass94]

Carb or intake cleaner to spray in there as well to help clean.

[Brian P]

how in bloody hell did you run the tank down to bone dry 16.94 gals? Lets make sure you're getting the right numbers before troubleshooting. And yes I've warned people about using Bosch anything on GM's, especially spark plugs and O2's, the most crucial parts to engine operation. Use AC Delco or Standard Motor Products. NGK might be alright too.

[xtremerevolution]

how in bloody hell did you run the tank down to bone dry 16.94 gals? Lets make sure you're getting the right numbers before troubleshooting. And yes I've warned people about using Bosch anything on GM's, especially spark plugs and O2's, the most crucial parts to engine operation. Use AC Delco or Standard Motor Products. NGK might be alright too.


I used NGK Iridiums for a while and I can definitely say I liked them. Never had any problems.

[Brian P]

I meant to say I was referring to O2 sensors in my post. I'm running NGK v-powers in both my cars and they're doing good!

[per0781]

I'm running NGK v-powers in both my cars and they're doing good!


same here brah. can't go wrong for 1.75 a spark plug.

[19Cutlass94]

Im running the AC Delco Iridium in my 3400. The plugs only have about 8,000miles on them so there was no point in changing them.

[rockfangd]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:

[Brian P]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!

[19Cutlass94]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!


If your filling the filler tube, you can fit over 17gallons.

[Brian P]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!


If your filling the filler tube, you can fit over 17gallons.


:eek: GTFO..... really?

[19Cutlass94]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!


If your filling the filler tube, you can fit over 17gallons.


:eek: GTFO..... really?


yes sir. The gas tank shound be 16.5 gallons, and if you run it wayyy down ( like Ive been down to the point of less than 1gal ) you can fit 17gallons in there. Itll take you a while cause the pump will keep kicking back, but you can fit it if you try.

[GP1138]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!


If your filling the filler tube, you can fit over 17gallons.


:eek: GTFO..... really?


yes sir. The gas tank shound be 16.5 gallons, and if you run it wayyy down ( like Ive been down to the point of less than 1gal ) you can fit 17gallons in there. Itll take you a while cause the pump will keep kicking back, but you can fit it if you try.


You don't want to do that though, because you'll flood your charcoal canister.

[19Cutlass94]

well around here and with these high gas prices ,sometimes it gets close when it is tight. i am really bad though. i have gone 2 days on 0 bars, :rolleyes:


You actually got 16.9 gallons to fit in one fill-up? I could be below E for 30 miles and when I fill up, it might take 15.5 gals the most. You're cutting it close there!!


If your filling the filler tube, you can fit over 17gallons.


:eek: GTFO..... really?


yes sir. The gas tank shound be 16.5 gallons, and if you run it wayyy down ( like Ive been down to the point of less than 1gal ) you can fit 17gallons in there. Itll take you a while cause the pump will keep kicking back, but you can fit it if you try.


You don't want to do that though, because you'll flood your charcoal canister.


not saying you want to, but its possible...




BTW, charcoal canister?!?!?!?! BBQ?

[GP1138]

BTW, charcoal canister?!?!?!?! BBQ?


:lol: That's what my auto shop teacher called the EVAP canister.

[Brian P]

taste the heat, not the meat!

[89SupremeCutty]

that's what i've always called it.