Let's talk about gas mileage
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From: Lancaster, Ohio
Car: 1992 Camaro RS V6
Engine: 3.1 V6 MFI
Transmission: 700R4
Axle/Gears: 3.23 stock
Re: Let's talk about gas mileage
Ugh, why would you want to swap in a 4-banger? 
Mileage maybe, but this isn't your daily driver is it? You can get more power and spend less with your current engine. V6 = fun with decent mileage; 4cyl = whiney lawnmower exhaust note and no fun. Just my oppinion.
Some 3rd gens came with a 4 cyl from the factory- the iron duke. I'd rather dunk my head in dog poo than put in a 4 cyl.

Mileage maybe, but this isn't your daily driver is it? You can get more power and spend less with your current engine. V6 = fun with decent mileage; 4cyl = whiney lawnmower exhaust note and no fun. Just my oppinion.
Some 3rd gens came with a 4 cyl from the factory- the iron duke. I'd rather dunk my head in dog poo than put in a 4 cyl.
lol, nice
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From: Western PA
Car: 91 Camaro
Engine: 3.1/3100 in progress...Turbo Soon
Transmission: 700r4
Re: Let's talk about gas mileage
I dont know...Seems like a lot of time and money for not that much fun.
If I were so worried about gas mileage that I would swap in a new engine I would get a new car or drop in an LS1. At least than it would still be a fun car and get good MPG.
If I were so worried about gas mileage that I would swap in a new engine I would get a new car or drop in an LS1. At least than it would still be a fun car and get good MPG.
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
This is the rear drive conversion for the Quad 4. If I had to run a 4 cylinder, this is the one.
http://www.mantapart.com/
Go to "engine parts" and then scroll down to the bottom of the page to where it says rear wheel drive conversion
http://www.mantapart.com/
Go to "engine parts" and then scroll down to the bottom of the page to where it says rear wheel drive conversion
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From: Minnesota
Car: 1998 Mustang
Engine: 3.8L V6
Transmission: Automatic with overdrive
Axle/Gears: 2.73:1 axle ratio
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From: Brandon Mississippi
Car: 1989 Camaro
Engine: 383
Transmission: 700R4
Axle/Gears: 3.73
Re: Let's talk about gas mileage
you guys can keep your 4 and 6 cylinder engine, The last time I checked my milage I was getting 25 to 28 depending on how I drive it. BTW, I have all the power a person would ever need for a street car and its a blast to drive.
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From: right behind you
Car: '85 maro
Engine: In the works...
Transmission: TH700 R4
Axle/Gears: 3.73 posi
Re: Let's talk about gas mileage
We're all happy for you, now go back to the v8 boards.
83camaroMN- that's about all you should expect out of the early carb'd 2.8's. They're hogs.
83camaroMN- that's about all you should expect out of the early carb'd 2.8's. They're hogs.
Joined: Sep 2004
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
DSmith says:
"Update, the engine is out of the car due to oil pump failure. I have a Holley Stealth Ram intake with 30# injectors to take the place of the TPI system. Not sure if I will stay with the 270/276 roller cam or not, I think that cam will be nice in my boat and a bigger one needs to be in my car. Time will tell."
So much for gas mileage...
Anyway, the old carb 2.8 setup isn't too bad on gas if you run the fuel injection long block (or at least the cam and heads) underneath it. When I dropped my 90 3.1 into a friend's carb S-10 he got nearly the mileage I did when it was in the bird. He was definitely happy. Those carb heads and cam are just plain awful. Ditto when we put an 88 bird 2.8 long block into an early 80's Citation. awesome power and much better mileage!
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Oh, and you need to ditch the 200 and put a 700R4 in.. that will also help A LOT.
"Update, the engine is out of the car due to oil pump failure. I have a Holley Stealth Ram intake with 30# injectors to take the place of the TPI system. Not sure if I will stay with the 270/276 roller cam or not, I think that cam will be nice in my boat and a bigger one needs to be in my car. Time will tell."
So much for gas mileage...
Anyway, the old carb 2.8 setup isn't too bad on gas if you run the fuel injection long block (or at least the cam and heads) underneath it. When I dropped my 90 3.1 into a friend's carb S-10 he got nearly the mileage I did when it was in the bird. He was definitely happy. Those carb heads and cam are just plain awful. Ditto when we put an 88 bird 2.8 long block into an early 80's Citation. awesome power and much better mileage!
----------
Oh, and you need to ditch the 200 and put a 700R4 in.. that will also help A LOT.
Last edited by KrisW; Feb 15, 2008 at 01:28 AM. Reason: Automerged Doublepost
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From: right behind you
Car: '85 maro
Engine: In the works...
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Re: Let's talk about gas mileage
Heh, I was looking at that too. Right now he's getting 0 miles per gallon.
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From: Brandon Mississippi
Car: 1989 Camaro
Engine: 383
Transmission: 700R4
Axle/Gears: 3.73
Re: Let's talk about gas mileage
But I'm not burning any gas. besides, now I have the same power at those 4 bangers. NONE!!!!!!!!!!!!!!!!!!
Joined: Sep 2004
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
WTF?!........
Joined: Jan 2005
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From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Let's talk about gas mileage
3.4 from a later model camaro was an EASY drop-in for my S10 with very few modifications.
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From: Minnesota
Car: 1998 Mustang
Engine: 3.8L V6
Transmission: Automatic with overdrive
Axle/Gears: 2.73:1 axle ratio
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From: right behind you
Car: '85 maro
Engine: In the works...
Transmission: TH700 R4
Axle/Gears: 3.73 posi
Re: Let's talk about gas mileage
You should get a little better than that, 12-15mpg range. If you put your foot in it alot you won't do much better than what you're getting. Try switching gear ratios to something numerically higher and you'll have better acceleration, and hopefully better mileage by keeping your foot off the gas. Mileage works on the psycological level as much as the mechanical level.
Last edited by bl85c; Feb 16, 2008 at 06:57 PM.
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From: Minnesota
Car: 1998 Mustang
Engine: 3.8L V6
Transmission: Automatic with overdrive
Axle/Gears: 2.73:1 axle ratio
Re: Let's talk about gas mileage
You should get a little better than that, 12-15mpg range. If you put your foot in it alot you won't do much better than what you're getting. Try switching gear ratios to something numerically higher and you'll have better acceleration, and hopefully better mileage by keeping your foot off the gas. Mileage works on the psycological level as much as the mechanical level.
my car you have to put it half way down just to get up to speed. Joined: Sep 2004
Posts: 2,777
Likes: 7
From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
I really think a 700R4 would help a lot with that. You'll have a 3.08 first gear to help get you going. You combine that with some 3.42's out back and you'll be getting along much better!
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From: right behind you
Car: '85 maro
Engine: In the works...
Transmission: TH700 R4
Axle/Gears: 3.73 posi
Re: Let's talk about gas mileage
Agreed, a th700 is the better way to go. Make sure to get an '84 with hydraulic tcc lockup, I don't think your ecm has any tcc control.
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From: Minnesota
Car: 1998 Mustang
Engine: 3.8L V6
Transmission: Automatic with overdrive
Axle/Gears: 2.73:1 axle ratio
Re: Let's talk about gas mileage
What do the 305 or 350's get for mileage I was thinking when my car dies I would gut it out and get a carbed 305 or 350 with a 700r4 from a 87 f body and 3.42's.
Joined: Sep 2004
Posts: 2,777
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
----------
Have you tried looking around at your local yards?
Last edited by KrisW; Feb 16, 2008 at 08:27 PM. Reason: Automerged Doublepost
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From: right behind you
Car: '85 maro
Engine: In the works...
Transmission: TH700 R4
Axle/Gears: 3.73 posi
Re: Let's talk about gas mileage
Not entirely sure, but I think the pre- '85 th700's had hydraulic tcc lockup.
There's quite a bit involved with a v8 swap, but already having a carb makes swapping in a carb'd v8 a little easier. You should look into a 3.4 block/fuel injection swap.
There's quite a bit involved with a v8 swap, but already having a carb makes swapping in a carb'd v8 a little easier. You should look into a 3.4 block/fuel injection swap.
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From: Kouts,IN
Car: 88 Firebird, 86 T/A
Engine: 3.1/305 short block
Transmission: 700r4 w/ transgo, vette servo/700r4
Re: Let's talk about gas mileage
Joined: May 2006
Posts: 577
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From: Minnesota
Car: 84' Trans Am
Engine: 5.0 H.O. L69
Transmission: 700R4
Axle/Gears: 3.73 Disc Brakes
Re: Let's talk about gas mileage
All of my other GM cars with the TH200 3 speed and 2004R 4 speed had electric tcc control; what had hydraulic control? 700R4?
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Too bad you're in Minnesotastan, I was touring my junkyards here and found 5, yes five, 3.4 multiport 4th gen engines in those yards. It would be soooo easy to retrofit your car with one of those...
Have you tried looking around at your local yards?
----------
Too bad you're in Minnesotastan, I was touring my junkyards here and found 5, yes five, 3.4 multiport 4th gen engines in those yards. It would be soooo easy to retrofit your car with one of those...
Have you tried looking around at your local yards?
Joined: Sep 2004
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Let's talk about gas mileage
I think all of the 87-95 rear drive 2.8/3.1/3.4 engines are about the same level of reliability. My experience has shown that these all tend to get well over 200k miles before needing a teardown.
So, in reality, if reliability and mileage are your only worries, then a low mile 87-up rear drive 60* engine is all you'll ever need!
So, in reality, if reliability and mileage are your only worries, then a low mile 87-up rear drive 60* engine is all you'll ever need!
Re: Let's talk about gas mileage
So what your guys are saying is; messing with my timing is not a good way to acheive mileage? Roger that, I wasn't sure. One of my friends with a ***** messed with his timing and got 40 mpg but it took his car from 120 to 90 HP. But those are probably alot more computer controlled than our cars. The vacuum leak is interesting. I do get a CEL sometimes, but it never stays on. The only line I havn't replaced is the one the goes from the back of the intake and then snakes around by the battery and disappears into the fender. I havn't had the time to pull the tire and the platic fender well in order to find out where it goes. But if there's a leak it's got to be that one. I already replaced the coolant temp sensor located under the TB.
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From: Waterford, MI
Car: 1998 Camaro Z28
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Transmission: 4L60E
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Re: Let's talk about gas mileage
Maybe I'm alone on this, but please dont necropost. What is the point in replying to a post that hasn't been commented on since February of LAST YEAR!!!!
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From: right behind you
Car: '85 maro
Engine: In the works...
Transmission: TH700 R4
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Re: Let's talk about gas mileage
I think this is the downside of telling people to use the search button all the time. They do, then ask again on an old thread.
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From: Scottsdale, AZ
Car: 89 GTA/93 S13/91 Si
Engine: 5.7 350 TPI
Transmission: 700R4
Axle/Gears: 3.23
Re: Let's talk about gas mileage
dang...u guys get mad when u dont get 20mpg??? O_o im excited when i get 15mpg...lmao
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From: York, Pa
Car: 84 olympic edition camaro
Engine: 2.8
Transmission: 700r4
Re: Let's talk about gas mileage
I'm getting 13-15 around town and 20-26 highway. My best was 28 on a all highway run. I'm running a carbed 2.8 with a full tune-up. When I rebuilt the carb I took my time tuning it so its on the edge of being too lean but it still runs good. Compared to everyone elses carbed mpg's I'm happy
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From: PA
Car: 1996 Camaro, 1985 Camaro
Engine: 3.8, 3.4
Transmission: WC T5, 700r4
Axle/Gears: 3.23(?), 3.42
Re: Let's talk about gas mileage
Didn't feel like reading every post so, I might repeat something but just my thoughts:
1. Better intake usually helps, if you have a dual snorkel don't buy a CAI, as dual snorkel is CAI by default, just gut the air boxes or ram air it.
2. Headers will help, as will a decent exhaust system, true duals is absolutely overkill for a stock-mild v6, honestly, true dual would probably LOWER your mileage because of the added weight.
3. I noticed BLC85 above me implying someone's thinking about a 4 banger, all I can say is NO, this is a ~3200 lb car, yes a 4 cyl uses less gas, but not if you have to gun it all the time to make your car get out of its own way, this would probably negate any decreases in fuel consumption due to smaller displacement/less cylinders, also even if a 4 cyl has as much power, look at the tq, I can pretty much guarantee it will be lower, a v just has more leverage.
4. I have yet to do my homework on timing, but I believe that advancing it helps highway mileage a little bit.
5. Generally speaking things that make an engine more powerful make it more efficient as well, provided you don't drive like I do.
6. The best way to increase mileage is probably tuning the crap out of your ECM, in which case you would also want to do an ECM swap:
https://www.thirdgen.org/forums/diy-...take-look.html
7.Also you might try buying an airfoil, though I have no idea if they work as well as implied in their descriptions.
8. Full tune up like everyone else has said, although they might not have mentioned seafoam, read up on it, you don't even want to know what my intake manifold looks like after 116k miles...the gunk is thicker than the metal its sitting in....
1. Better intake usually helps, if you have a dual snorkel don't buy a CAI, as dual snorkel is CAI by default, just gut the air boxes or ram air it.
2. Headers will help, as will a decent exhaust system, true duals is absolutely overkill for a stock-mild v6, honestly, true dual would probably LOWER your mileage because of the added weight.
3. I noticed BLC85 above me implying someone's thinking about a 4 banger, all I can say is NO, this is a ~3200 lb car, yes a 4 cyl uses less gas, but not if you have to gun it all the time to make your car get out of its own way, this would probably negate any decreases in fuel consumption due to smaller displacement/less cylinders, also even if a 4 cyl has as much power, look at the tq, I can pretty much guarantee it will be lower, a v just has more leverage.
4. I have yet to do my homework on timing, but I believe that advancing it helps highway mileage a little bit.
5. Generally speaking things that make an engine more powerful make it more efficient as well, provided you don't drive like I do.
6. The best way to increase mileage is probably tuning the crap out of your ECM, in which case you would also want to do an ECM swap:
https://www.thirdgen.org/forums/diy-...take-look.html
7.Also you might try buying an airfoil, though I have no idea if they work as well as implied in their descriptions.
8. Full tune up like everyone else has said, although they might not have mentioned seafoam, read up on it, you don't even want to know what my intake manifold looks like after 116k miles...the gunk is thicker than the metal its sitting in....
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From: in my car
Car: 1987 Gta Trans Am
Engine: 383 Stroker
Transmission: t-56
Axle/Gears: 3.47 02 SS rear end
Re: Let's talk about gas mileage
"premium" gas is just regualar old gas... that burns slower. Dosent help a damn thing if your engine dosent need it. You dont have a turbo and you dont have high compression. your actually paying more AND hurting performance by buying premium.
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From: Davenport, Iowa
Car: Still a 3rd Gen
Engine: 450HP 355
Transmission: TH350
Axle/Gears: 9" with 4.11's
Re: Let's talk about gas mileage
with 42 degrees of advance, lean cruse mode enabled and averaging a 16.0 afr (on the wideband) i was getting right around 35 mpg on the highway in my 3500 swapped cavalier. That was a steady RPM in 5th, minimal passing.
The problem was that $A1 doesn't have "highway mode spark advance" so when i got back into town and was running through the gears i'd hit the high values in the SA table and the car would buck. i set it back down to 35 degrees and left it alone till i could find a better code to run. I'm probably going to use $DF which is for the 3.4 DOHC. It's got some nice extras in it.
The problem was that $A1 doesn't have "highway mode spark advance" so when i got back into town and was running through the gears i'd hit the high values in the SA table and the car would buck. i set it back down to 35 degrees and left it alone till i could find a better code to run. I'm probably going to use $DF which is for the 3.4 DOHC. It's got some nice extras in it.
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From: PA
Car: 1996 Camaro, 1985 Camaro
Engine: 3.8, 3.4
Transmission: WC T5, 700r4
Axle/Gears: 3.23(?), 3.42
Re: Let's talk about gas mileage
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