Is V6 in a F-body better on gas?
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Junior Member
Joined: Sep 2003
Posts: 28
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From: Montreal
Car: 1994 Firebird
Engine: V6 3.4L
Transmission: Auto
Is V6 in a F-body better on gas?
Alright , now i have a modified V8 Transam, I need something better on gas because it's my daily driven car. So i figured, hey why not get a V6 f-body, since well i also need a winter car, and i'm to much of an f-body freak to get anything else. So anyways, i was told there isn't much different between and 6 and 8cyl, since the 6 would have to force more to pull the weight of the car, (since they are decently heavy cars), now u guys seem to have V6s, do you noticed a difference in gas/milage from v6 & v8 in f-bodies?
Thanks.
Thanks.
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Joined: Feb 2003
Posts: 109
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From: Avon Lake, OH
Car: 84 Camaro Z28
Engine: 305 L69
Transmission: 700r4
if you get a light sc with Fuel injection in good tune, with a 5 speed and you can shift well I would say prolly someware 25-30 mpg maybe more. But that goes right down if you can't keep your foot off the floor
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From: Tucson, AZ, USA
Car: '99 Trans Am, '86 Camaro
Engine: LS1, Scrap
Transmission: T56, T5
Axle/Gears: 3.42 Stock ZT, 3.42 Open
For gas milage, you'd probably do better with a smaller/lighter car... F-body gas milage differences are negligable in my experience.
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Joined: May 2003
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From: Shelby Twp. MI
Car: 91 Z28
Engine: Rebuilt and modified 350
Transmission: rebuilt T-5
I have a 3.1L, and I usually get about 200 miles/tank. My 4 banger Acclaim used to get twice that. If you can, look into an "Iron Duke" Camaro
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From: St. Louis, MO
Car: 85' Firebird (Project), 92' RS
Engine: 2.8L, LS1
Transmission: 700R4, 4L60E
Axle/Gears: 3.42 Open , 10 Bolt (ukn)
iron duke probably wouldn't save that much on gas, neihter will a v6 the hold back is the f-bodies weight and you need poewr to pull the car. Because of this, a v6 will get just about as much gas milage as an 8, unless you can truely drive w/ an egg under you foot. As that you will need to keep your foot farhter down on the gas in order to get the same acceleration.
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From: Tucson, AZ, USA
Car: '99 Trans Am, '86 Camaro
Engine: LS1, Scrap
Transmission: T56, T5
Axle/Gears: 3.42 Stock ZT, 3.42 Open
Rare does not mean desireable. If I saw one.... .. actually, I wouldn't even think of buying it, regardless of price, unless I needed parts off it.
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Joined: Feb 2004
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From: Tucson AZ
Car: 89 Firebird
Engine: 2.8 V6
Transmission: 700R4
My Bird gets pretty good mileage for the weight of the car. but the smaller the motor and less Hp and Tq the more the motor has to work.
I had the Tech 4 Iron Duke in several of my Fiero's (lighter cars 2580) the best one was my 87 SC with a 5 speed with around 75,000 and in great shape on the open interstate between Oklahoma and Louisiana when I would dare drive a car that small that far would get around 38-40Mpg at a steady 80-85 with the ac going.
I am sure it would have been better but at that speed the rpms are running like 3-3500 in the iron Duke. The Duke isnt that bad of a motor if its taken care of right and you keep it in good shape (in a F-Body) my thoughts are you have to be kidding right, The Fiero was ok with the 2.5 but in a larger car no way!
I woulad think that the basic V6 would get about the same as a good shape 350 Fi would get as well because of the hp loss in the V6 (Am I wrong?)
Donnie H.
I had the Tech 4 Iron Duke in several of my Fiero's (lighter cars 2580) the best one was my 87 SC with a 5 speed with around 75,000 and in great shape on the open interstate between Oklahoma and Louisiana when I would dare drive a car that small that far would get around 38-40Mpg at a steady 80-85 with the ac going.
I am sure it would have been better but at that speed the rpms are running like 3-3500 in the iron Duke. The Duke isnt that bad of a motor if its taken care of right and you keep it in good shape (in a F-Body) my thoughts are you have to be kidding right, The Fiero was ok with the 2.5 but in a larger car no way!
I woulad think that the basic V6 would get about the same as a good shape 350 Fi would get as well because of the hp loss in the V6 (Am I wrong?)
Donnie H.
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Joined: Oct 2001
Posts: 718
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From: Hliðskjálf / Pensacola, FL
Car: Camaro
Engine: 3800
Transmission: T5
GTA in sig got 26/7 MPG cruising at 70 back when it had the automatic.
Best my Camaro got was 25 (when it was a 3.4L 5 speed with like 800 miles on the new motor), but it had a couple problems with it. I've read on here that the 3.4L's are supposed to be better on gas, but I haven't seen numbers other than "xxx on a tank" which in my opinion doesn't say much... b/c from my experience the gas gauges aren't excessivly accurate.... at least I wouldn't trust mine past the 1/4 tank mark *shrug*

-Bud
Best my Camaro got was 25 (when it was a 3.4L 5 speed with like 800 miles on the new motor), but it had a couple problems with it. I've read on here that the 3.4L's are supposed to be better on gas, but I haven't seen numbers other than "xxx on a tank" which in my opinion doesn't say much... b/c from my experience the gas gauges aren't excessivly accurate.... at least I wouldn't trust mine past the 1/4 tank mark *shrug*

-Bud
I routinely get about 20 PLUS MPG in town.
I get over 25 MPG EASILY on interstate.
Best was 28 MPG at constant 80-85MPH w/AC & full load of family.
YET for what I said, I put a ton of work into the ride to get these results.
Go buy a "newer" car for your money spent.
Don't waste time under the hood, just buy a dead boring reliable "appliance". I rented a Chevy something, recently. Little buzz box, but great on gas & power! Probably about $6-8,000 used from a rental car reseller dealership. Don't knock that option. Those cars are maintained well. Just ask for a "loan" period before ya say done deal with money.
Keep your Trans Am, worth way more real soon!
I get over 25 MPG EASILY on interstate.
Best was 28 MPG at constant 80-85MPH w/AC & full load of family.
YET for what I said, I put a ton of work into the ride to get these results.
Go buy a "newer" car for your money spent.
Don't waste time under the hood, just buy a dead boring reliable "appliance". I rented a Chevy something, recently. Little buzz box, but great on gas & power! Probably about $6-8,000 used from a rental car reseller dealership. Don't knock that option. Those cars are maintained well. Just ask for a "loan" period before ya say done deal with money.
Keep your Trans Am, worth way more real soon!
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Joined: Apr 2003
Posts: 254
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From: Ocala, FL
Car: 95 Mustang GT Vert
Engine: 5.0
Transmission: T5
Doward here... still working on the turbo project. 
Anywho, 320 miles before I fill up, clicking 26.3 mpg, with my foot in the floor. I can get 30 if I'm REALLY easy on it.
What's all this about the Fbody being so heavy?
My '88 SC (2.8/T5) weighs in @ 2950 on a CAT scale - WITH a 1/2 tank of gas!
Of course, I have power NOTHING. The only options I have, are A/C and Radio.

Anywho, 320 miles before I fill up, clicking 26.3 mpg, with my foot in the floor. I can get 30 if I'm REALLY easy on it.
What's all this about the Fbody being so heavy?
My '88 SC (2.8/T5) weighs in @ 2950 on a CAT scale - WITH a 1/2 tank of gas!
Of course, I have power NOTHING. The only options I have, are A/C and Radio.
Supreme Member
Joined: Oct 2001
Posts: 8,113
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From: NWOhioToledoArea
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
Weight is the problem as people expect it to move like a V8 and over use the pedal.
I bet if you would put a 2800-3000 rpm limiter on a stick, you may get near 40.
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I don't consider weight being a factor as it how people drive use the pedal trying to get v8 speed out of a 6.
I bet if you would put a 2800-3000 rpm limiter on a stick, you may get near 40.
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I don't consider weight being a factor as it how people drive use the pedal trying to get v8 speed out of a 6.
Supreme Member
Joined: Mar 2000
Posts: 2,028
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From: St. Louis, MO
Car: 85' Firebird (Project), 92' RS
Engine: 2.8L, LS1
Transmission: 700R4, 4L60E
Axle/Gears: 3.42 Open , 10 Bolt (ukn)
that's the typical problem dow, people try to get more performance out of a car w/ less performance and the end result, poorer gas millage, drive the car like it was supposed to be driven (the economy version of the muscle car) and chances are, we'd be seeing pretty decent gas milage, gonna go easy on the pedal today, (have 200 miles to run, and i'll see how well she holds up)
Senior Member
Joined: Mar 2004
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From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
i live in new york city, gas milage sucks since as soon as i barelly hit 40 mph i have to stop, stupid lights and stop signs. my car gets about 120 on a full tank in the city... on the highway i can at least get a good 200, then again i need to tune my car up, imo its waisting to much gas, think its cause of leaky injectors *smell of gas coming from hood can kil me with t-tops off*
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Joined: Aug 2002
Posts: 3,827
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From: Gainesville, FL
Car: 1988 Chevy Camaro Hardtop
Engine: Turbocharged/Intercooled 3.1
Transmission: World Class T5 5 Speed
Originally posted by Gumby
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I take that title!!I ROUTINELY shift into 5th gear @ 30mph. I can cruise along with traffic nicely, if I'm heading down the back roads.
Even driving normally, I don't shift hardly over 2250 or so.
Now, if I'm in a hurry, it's about 4300 or so, between shifts.
Racing is 5300!
NYC!
Visions of my Dad stuck on 5th Ave in a 55 Chevy & stuck 3 on tree tranny shifter.
I used to race taxicabs in Central Park at Midnight for fun!
And you are brave enough to drive an old F Body in NYC.......
I Tip my Hat to You!
How much are pedestrians worth these days?
Still extra points for Moms & Baby Strollers?
Bicyclists worth more points moving or stationary?
Used to be a video game in a Times Square arcade like that. Was the BEST!
Wave hi to "Atlas" for me.
Visions of my Dad stuck on 5th Ave in a 55 Chevy & stuck 3 on tree tranny shifter.
I used to race taxicabs in Central Park at Midnight for fun!
And you are brave enough to drive an old F Body in NYC.......
I Tip my Hat to You!
How much are pedestrians worth these days?
Still extra points for Moms & Baby Strollers?
Bicyclists worth more points moving or stationary?
Used to be a video game in a Times Square arcade like that. Was the BEST!
Wave hi to "Atlas" for me.
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Joined: Dec 2000
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From: UCIrvine or SFV, CA
Car: 1999 Pontiac Trans Am
Engine: LS1 - 346 ci
Transmission: 4L60E
Today I filled up, and I think it's been an amazing improvement since I've had the tires aligned! Now many of you might think that's absurd, but if you notice on TomP's tuneup, it says get an alignment. I picked up at least 5 MPG since I got it aligned. Today I calculated about 23.375 MPG, really good for my V6 which used to get about 16.
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From: UCIrvine or SFV, CA
Car: 1999 Pontiac Trans Am
Engine: LS1 - 346 ci
Transmission: 4L60E
Originally posted by KED85
IS that improvment based upon more or less UCI coeds in the car?
IS that improvment based upon more or less UCI coeds in the car?
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Joined: Nov 2001
Posts: 827
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From: Tenino, Washington
Car: 89 f-bird and some others
Engine: 3.4
Transmission: 700R4
Axle/Gears: 3.42
i get about 320 per tank, 340 if i really pushed it. If you're going to do alot of freeway driving I think the v6 might get a little better mileage than the v8. Someday after i have a job i might get a V8 for fun and then i'll get to see for myself what the difference is.
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Joined: Mar 2004
Posts: 800
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From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
yeh some old man had told me i had ***** to drive my fbody around in the city, he owned a 71 trans am, 6.6, he said he had to sell it being that he was going to end up killing himself driving that thing around the city , to much power.. :hail:
Supreme Member
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From: Gainesville, FL
Car: 1988 Chevy Camaro Hardtop
Engine: Turbocharged/Intercooled 3.1
Transmission: World Class T5 5 Speed
The biggest reason the V8's get good gas mileage, is sheer torque + 2.73 gearing!
Why do you think a 3.1 / T5 is faster than a 305 TBI auto?
Why do you think a 3.1 / T5 is faster than a 305 TBI auto?
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Joined: Oct 2001
Posts: 8,113
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From: NWOhioToledoArea
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
Originally posted by Doward
The biggest reason the V8's get good gas mileage, is sheer torque + 2.73 gearing!
Why do you think a 3.1 / T5 is faster than a 305 TBI auto?
The biggest reason the V8's get good gas mileage, is sheer torque + 2.73 gearing!
Why do you think a 3.1 / T5 is faster than a 305 TBI auto?
some old man had told me i had ***** to drive my fbody around in the city, he owned a 71 trans am, 6.6,
I once drove my 1966 Corvette stick shift in NYC. Best point & take drive lane spot car I had!
My Dad had also driven a 1963 Grand Prix, 421, automatic, there too. The Door Guys LOVED parking that car!
My favorite was my 1975 Vega 4-speed stick shift 2 BBl engine. I only threw the alignment out once on that car and it was by the docks. That car was the best against the Taxis in Central Park at midnight.
You'll never see "The French Connection" chase scene filmed in NYC again!
How's the pizza, lately?
I once drove my 1966 Corvette stick shift in NYC. Best point & take drive lane spot car I had!
My Dad had also driven a 1963 Grand Prix, 421, automatic, there too. The Door Guys LOVED parking that car!
My favorite was my 1975 Vega 4-speed stick shift 2 BBl engine. I only threw the alignment out once on that car and it was by the docks. That car was the best against the Taxis in Central Park at midnight.
You'll never see "The French Connection" chase scene filmed in NYC again!
How's the pizza, lately?
Senior Member
Joined: Mar 2004
Posts: 800
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From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
haha thats great ked, seems like you been around my way, driving in the city is fun , not so fun when u are tired and have to swerve to dodge holes.. pizza is still good, depending where you go , seems like you owned some pretty descent muscle cars.. btw where did you find that old man? you really think it was the same guy, did he tell you about opening her up on a highway that has no trucks ?
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From: surrey b.c. canada
Car: 89 Iroc
Engine: lb9
Transmission: wc t-5
Axle/Gears: 10 bolt 3.08 posi
Originally posted by Gumby
Weight is the problem as people expect it to move like a V8 and over use the pedal.
I bet if you would put a 2800-3000 rpm limiter on a stick, you may get near 40.
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I don't consider weight being a factor as it how people drive use the pedal trying to get v8 speed out of a 6.
Weight is the problem as people expect it to move like a V8 and over use the pedal.
I bet if you would put a 2800-3000 rpm limiter on a stick, you may get near 40.
I am the king of short shifting and getting into 5th asap and not even reaching 3000 each time you will clicking alone at 50-60 in a sec.
I don't consider weight being a factor as it how people drive use the pedal trying to get v8 speed out of a 6.
Senior Member
Joined: Mar 2004
Posts: 800
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From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
thats cool i notice plenty of third gens around here, correction i mean camaros, not to many firebirds, and if you do see them its just a daily beater for some old mexican . have yet to see another 90 firebird, closest ive seen was a 90 trans am, my color , very sweet
:hail:
:hail: Supreme Member
Joined: Oct 2001
Posts: 8,113
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From: NWOhioToledoArea
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
It has been already mentioned kind of but if you consider the V6 3rd gen has 3:42s stock, that is more of a speed gear. Put some normal 2:73 highway gears in a T5 6 and the mileage should rocket.
We got some good gearing but not really mileage gearing , even though it doesn't do that bad.
We got some good gearing but not really mileage gearing , even though it doesn't do that bad.
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From: St. Louis, MO
Car: 85' Firebird (Project), 92' RS
Engine: 2.8L, LS1
Transmission: 700R4, 4L60E
Axle/Gears: 3.42 Open , 10 Bolt (ukn)
well, i was going to get the stupid MPG estimate but, the damn car was acting up. Get this, code 13 , 50 miles from school, and yeh, acted stupid the whole rest of the way home. Haven't tried to get anther reading , maybe we'll give it a try later.
Senior Member
Joined: Mar 2004
Posts: 800
Likes: 0
From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
like i said my v6 is horrible, getting 120 per tank, i get a horrible smell of gas sometimes, do you guys think it could be my injectors? when i get that horrible smell of gas it seems to act up starting it up, stalls then takes a while to start up again, seems to be flooded with gasoline ,(Sorry for getting off topic )
Senior Member
Joined: Oct 2001
Posts: 718
Likes: 1
From: Hliðskjálf / Pensacola, FL
Car: Camaro
Engine: 3800
Transmission: T5
Originally posted by Gumby
It has been already mentioned kind of but if you consider the V6 3rd gen has 3:42s stock, that is more of a speed gear. Put some normal 2:73 highway gears in a T5 6 and the mileage should rocket.
We got some good gearing but not really mileage gearing , even though it doesn't do that bad.
It has been already mentioned kind of but if you consider the V6 3rd gen has 3:42s stock, that is more of a speed gear. Put some normal 2:73 highway gears in a T5 6 and the mileage should rocket.
We got some good gearing but not really mileage gearing , even though it doesn't do that bad.
....I wonder if these cars would be able to keep going on the interstate with 2.73s without mashing the pedal down further. That'd be interesting to try for sure.

-Bud
The answer to ANY gas milage question begins (atleast with our 3rd Gen models) to be TORQUE and the final gearing.
New modern cars get by on more fancy electronics & lighter body mass to move.
Remember the Firebird is the most aerodynamic car "made", and those .032 numbers do still hold well, today.
4 cylinders were sold to please EPA milage demands, not public desire.
4 cylinder Fieros are great fun ride, tho. IF ya got reliable drivetrain.
New modern cars get by on more fancy electronics & lighter body mass to move.
Remember the Firebird is the most aerodynamic car "made", and those .032 numbers do still hold well, today.
4 cylinders were sold to please EPA milage demands, not public desire.
4 cylinder Fieros are great fun ride, tho. IF ya got reliable drivetrain.
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Joined: Mar 2000
Posts: 2,028
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From: St. Louis, MO
Car: 85' Firebird (Project), 92' RS
Engine: 2.8L, LS1
Transmission: 700R4, 4L60E
Axle/Gears: 3.42 Open , 10 Bolt (ukn)
agreeing with karl here, the gearing it takes to move a car like this when you're underpowered in the torque department will create a need for more gas to do the same amount of work. In order to compensate for this "higher rev" the cars got better gearing, better for performance worse for cruise, 2.73 is awesome if you want highway gas milage, but in a six forget about acceleration. Also, although the f-body's aerodynamics are very important (especially the firebird) off the line and city driving won't let them play a part, however on the highway, they do exceptionally well.
I'd really like to see what my girls car can do w/ a 4th gear, or better yet a 5speed. She has one of those chevy prizms (the ones geo made) and it's only got a 3spd automatic in it, car will still pull 30mpg on the highway unless you start going over 80 when it becomes a gas hog.
I'd really like to see what my girls car can do w/ a 4th gear, or better yet a 5speed. She has one of those chevy prizms (the ones geo made) and it's only got a 3spd automatic in it, car will still pull 30mpg on the highway unless you start going over 80 when it becomes a gas hog.
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From: Indianapolis, IN
Car: 02 WS6, 83 WS6, and 78 Project
Engine: LS1, LG4, and 400
Transmission: 4L60E, T5, and TH400
Axle/Gears: 3.73, 3.73, and 2.73
My 2.8 V-6 auto get between 24-28 usually, and I also drive it like I stole it constantly.. that has new tires, well kept, and new shocks.. the 'bid I just got.. well, thats another story. Its a 305 auto, shot tires, needs an alignment BADLY, shocks are shot and I hmmered it constantly and STILL got MORE milage than the Camaro.. was averaging 29-32 with it! Cant wait to rip it down more and repair those things and see how it REALLY does!
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From: Ontario
Car: IROC Z
Engine: 5.7
Transmission: 700R4
put on 15" rims as opposed to 14"s and id bet your milage would go up. your odo and speed o would be off but the $ into your tank would show youre getting better gas milage
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Posts: 124
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From: Indianapolis, IN
Car: 02 WS6, 83 WS6, and 78 Project
Engine: LS1, LG4, and 400
Transmission: 4L60E, T5, and TH400
Axle/Gears: 3.73, 3.73, and 2.73
Lol... actually I already put 15" '83 T/A Turbo fin rims on my Camaro.. the 'Bird has 16".. but still.. lol.. but thanks for the tip.
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From: Ontario
Car: IROC Z
Engine: 5.7
Transmission: 700R4
i get really bad milage with both my cars.
put 10$ in the lincoln yesterday got 51 kilometers in the city...
and my camaro has no over drive until i reach highway speeds, so it sucks in the city.
put 10$ in the lincoln yesterday got 51 kilometers in the city...
and my camaro has no over drive until i reach highway speeds, so it sucks in the city.
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Joined: Mar 2004
Posts: 800
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From: Ozone Park, NYC
Car: 1990 firebird
Engine: 3.1 v6
Transmission: 700R4
yeh thats why my car sucks in the city, over drive doesnt kick in unless im flying down busy streets , when od kicks in i can do 30 miles and not even notice a drop in the fuel guage
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From: Fl.
Car: 83 Trans Am / 96 Jeep XJ
Engine: 355 / 4.0 I6
Transmission: TH350 / Auto
Axle/Gears: 3.23 10-bolt / 4wd
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