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Bad Mileage !!

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Old 03-30-2003, 04:46 PM
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Bad Mileage !!

hey guys, anyone wanna tell me why i get such bad gas mileage from my 305 TBI A4 (stock), I filled up today and i calculated 10.4 MPG.
Please help me, or i wont be able to afford gas
Old 03-30-2003, 04:58 PM
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Car: '88 GTA
Engine: L-98
Transmission: T-56
hell i get a lil over 12mpg but thats because i dont drive on the highway much.....but when i do take a long trip i get about 20mpg on the highway, id suggest a tuneup including an oxygen sensor, and try to keep your foot outta the gas as much
Old 03-30-2003, 05:11 PM
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yea, i hardly ever drive on the freeway, mainly small city driving. thanks for the help
Old 03-30-2003, 05:57 PM
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Car: 91 Camaro RS Convertible
Engine: 305 TBI
Transmission: 5-Speed
Axle/Gears: 3.42
I'd agree with the tuneup, go for a full tuneup because our TBI 305's can get really good gas mileage when in tune, I get close to 20 city and about 27 on the highway.
Old 03-30-2003, 06:52 PM
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Engine: slowtacular L03 305
Transmission: slushem 700r4
I generally get poor gas milage in city until i start driving for more than about 5 minutes, then she warms up and runs better, still needs a tuneup, but i am managing about 25-28mpg on the highway and up to 30 with a tail wind.
Old 03-30-2003, 07:01 PM
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so basically, the moral of the story is get a tuneup?, lol
Old 03-30-2003, 10:14 PM
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Originally posted by RSstocker
so basically, the moral of the story is get a tuneup?, lol
nope, not necessarily.

mine runs just fine, everything is in tune as best i know how, but i get 12 city/ 21 highway with a 3.42 rear.

but it should help you some.
Old 03-30-2003, 11:20 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
Originally posted by v8unleashed
nope, not necessarily.

mine runs just fine, everything is in tune as best i know how, but i get 12 city/ 21 highway with a 3.42 rear.

but it should help you some.
that gear should not affect city mileage at all. i just got 13.7 MPG with my setup. check the first link in the sig, ALL CITY. no highway, all stop and go. shows that carbs arent all that bad...

oh and yes i had her WOT many times on that tank....
Old 03-31-2003, 06:13 AM
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Originally posted by brodyscamaro
that gear should not affect city mileage at all.
first, i didnt say it should......

but......

i still think it would; why wouldn't it? the engine is still spinning faster, not only at highway speeds.

maybe gearing wouldnt affect it, using the logic that maybe the car will now shift into 3rd where it used to stay in 2nd or something like that. is that what you mean? explain.
Old 03-31-2003, 07:59 AM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
Because of your OD city driving isn't affected. RPMs are still low, and it's acutally easier to get the car moving with the 3.42 gear.
Old 03-31-2003, 12:28 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
Originally posted by v8unleashed
mine runs just fine, everything is in tune as best i know how, but i get 12 city/ 21 highway with a 3.42 rear.
i had similiar numbers from my LO3. i still think should be getting better mileage in the city. you run the car hard?
Old 03-31-2003, 12:45 PM
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Car: '88 GTA
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i think my biggest gas milage problem is my right foot especially since i got my exhaust done, it just sounds mean when i get on it
Old 03-31-2003, 02:10 PM
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Originally posted by brodyscamaro
you run the car hard?
about as hard as i can, but i also do alot of idling. here at school the town has two types of people -- old people and tourists, neither of which know where they're going and neither of which even come close to the speed limit. one gets real pissy real fast driving behind someone going 22 in a 45.

when i get home next time to a timing light im gonna try and see if the infamous LO3 timing bump helps out. there's nothing else to try really, just about EVERYTHING is fairly new, and the car runs great.
Old 03-31-2003, 07:26 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
yeah, that would explain it. i know how ya feel about those other drivers. and it seems that they are everywhere (crappy drivers)
Old 03-31-2003, 10:02 PM
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My completely stock 305 tbi gets 17-18 mph city. I dont know what I get highway as most of my driving is city. I drive pretty easily, but nothing extremely granny like, lol.
Old 03-31-2003, 10:32 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
thats seems within normal limits. IIRC my LO3 got between 12 and 16 city...
Old 03-31-2003, 10:35 PM
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my car seems to run perfect and i hardly ever get on the gas, so i dont know what to check out because i had new plugs, 02 sensor and a few other things replaced when they put the new engine in. I even went so far as to totally drive like a granny to see what kinda mileage i got, so the 10.4 kinda pissed me off, but i seem to be getting good gas mileage so far on this tank, i have 50 miles on the tank and my gauge reads less than 1/8 of a tank used, but knowing those stupid gauges it will probably jump to half of a tank tommorow
Old 03-31-2003, 10:55 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
i would not trust the gauge at all. i dont even recall when i last looked at mine and i drive everyday
Old 03-31-2003, 10:58 PM
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Car: '91 t-top RS; '91 hrdtp Z28
Engine: LO3;383tpi
Transmission: 700r4;very nice 700r4
Axle/Gears: 4.10 zt posi, 3.70 auburn
Yeah, the gas gauge is really inaccurate. As far as city milage goes, I actually got better milage after I swapped to 3.73s. Highway suffered a little though. Prior to my tranny swap, I was getting 17mpg city and 22 highway with those gears. Stock gears left me with 15mpg city and 24mpg. Of course after the six speed swap, highway was more like 28mpg. Never did figure out what city was before the engine blew, it was to hard to keep off the gas
As far as your origional question goes, It could be a number of things. I can say that the MSD 6A bumped my milage up 1.5mpg. What thermostat are you running? If your engines not warming up, that would have a big effect. If your plugs were black with carbon, that is also an indicator you're running pretty rich. A clogged cat and/or dirty air filter will also hurt milage.
Old 03-31-2003, 11:06 PM
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actually mine seems to be pretty accurate from what i have calculated, and the time that i didnt trust it when it said it was empty, i ended up running out of gas, and i felt really stupid.
Old 04-01-2003, 04:09 PM
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Car: '91 t-top RS; '91 hrdtp Z28
Engine: LO3;383tpi
Transmission: 700r4;very nice 700r4
Axle/Gears: 4.10 zt posi, 3.70 auburn
Every camaro/firebird I know of with the exception of the 1LE package reads off. It usually seems like you get awesome milage until the gauge hits half a tank, in which case it just seems to be gulped up. It's because of the way the tank is shaped. Just something to keep in mind. Make sure you use the actual number of gallons between fill-ups as opposed to assuming you have 7.5 to 8 gallons left because your gauge reads half a tank.
Old 04-01-2003, 04:47 PM
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i keep good records on gas mileage and trust me, im not dumb and i dont calculate my mileage from the gauge, i do it by how much gas i put into it and i set my trip as soon as i leave the pump,
Old 04-01-2003, 07:43 PM
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You might want to get ah locking gas cap. There's more than one way gas can disappear.

Steve
Old 04-01-2003, 08:18 PM
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maybe, lol HITHERE wouldnt put it past some of the people HITHERE know, but HITHERE dont think thats it, and does anyone know why HITHERE keep seeing HITHERE in place of HITHERE's and HITHERE ?
Old 04-01-2003, 09:03 PM
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Car: 93 Caprice 9C1
Engine: L05
Transmission: 4L60
Axle/Gears: 3.42
Uh, site got hacked? Pretty damn funny though. Actually, it's really really obnoxious.

Hey look, HITHERE'm an administrator, too!

Oh wait, that will just cause more hi there's.....uh....me is an administrator
Old 04-01-2003, 10:07 PM
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hell yea its annoying eye cant even read the posts right, hopefully it gets fixed soon or eye'll go crazy . Like how eye use eye instead of eye ? lol

Last edited by RSstocker; 04-01-2003 at 10:09 PM.
Old 04-04-2003, 10:16 AM
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Car: '90 Camaro RS T-Top
Engine: 5.0 TBI
Transmission: TH700R4
The mileage of my car pisses me off... it's an L03 TBI A4, with a K&N filter, and 3" two into one exhaust, smog equipment removed, otherwise is stock. I do mostly city driving (some uphills and downhills here) and get about 13mpg. on a trip to the beach I estimated 16mpg. I thought it would do at least 18mpg in the city.... gonna have to check those plugs to see if it's running rich..



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Old 04-04-2003, 11:23 AM
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Right now, I'm getting about 13.2 mpg with my LO3

ALL CITY driving, and i have NEVER taken it above 3,000 rpms...

But, it needs a tune-up BAD, so i'll post after that...

Generally i always hear to improve gas mileage, get a tune-up new air filter, and make sure the car is running properly....
Old 04-04-2003, 11:52 AM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
It seems like with LO3s people usually get 13city or people claim some **** like 22mpg all city. no in-between
Old 04-04-2003, 11:53 AM
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Car: 1990 Camaro RS
Engine: Juiced 5.0 TBI - 300rwhp
Transmission: T5
Axle/Gears: 3.42 Eaton Posi, 10 Bolt
Originally posted by brodyscamaro
It seems like with LO3s people usually get 13city or people claim some **** like 22mpg all city. no in-between
i get 18-20 city, and 25ish hiway.
Old 04-04-2003, 12:00 PM
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Sub 10's city. I cant find whats wrong with it. Everything seems ok. I think its me. Every car I have ever owned got less than 12 consistantly.

I'm gonna run it on the highway tommorow and see what happens. (I hope I dont run out.)
Old 04-04-2003, 02:02 PM
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Car: 1999 Yamaha Banshee
Engine: 379cc twin cyl 2-stroke stroker
Transmission: 6 spd manual
Axle/Gears: 14/41 tooth
fill it up and run it on the highway like 20 miles or so, then turn around drive 20 miles back and fill it up again
calculate your highway mileage, or course the farther you drive the more accurate it is but 40 miles is close enough in my book
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