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2.73 to 3.42 mpg difference

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Old Jun 6, 2010 | 06:33 AM
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Default 2.73 to 3.42 mpg difference

Hey guys I really wanted to do a stall but wat told t would suck with the stock gears so here I am lol. My only big concern is fuel economy which is why I'm lookin at 3.42s over the 3.73s after skme calculations it's lookjn like I'd b spinning 2500 rpms at 80 instead if the 2000 I do now. Is that enough to completely tank my mpg? Only reason I'm worry is cuz 3.73s put the car at 3000rpms at 80 which I saw drops mpg down to any 21 on the highway.
Thanks Dan
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Old Jun 6, 2010 | 08:07 PM
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Originally Posted by redbird555
Hey guys I really wanted to do a stall but wat told t would suck with the stock gears so here I am lol. My only big concern is fuel economy which is why I'm lookin at 3.42s over the 3.73s after skme calculations it's lookjn like I'd b spinning 2500 rpms at 80 instead if the 2000 I do now. Is that enough to completely tank my mpg? Only reason I'm worry is cuz 3.73s put the car at 3000rpms at 80 which I saw drops mpg down to any 21 on the highway.
Thanks Dan
I use to have a 00 z28 and went to 342's I really didn't notice much of a different in mpg at all. I wish I would have done a converter insead of gears though. I saw a guy with a 3400 stall, full exhaust,cam, and a nitrous kit go 10's with 273 gears. But that was after I did my gears wish I would have done the stall instead of gears for sure.
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Old Jun 6, 2010 | 08:11 PM
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You won't notice a difference. I'm about to go from 3.23's to 3.73's and a 3200 stall. Just the gears alone won't cut your mpg in half or anything, but a stall will reduce your mpg a lot more.
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Old Jun 6, 2010 | 09:33 PM
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I went from 2.73 to 3.73. I haven't noticed a difference in MPG. It still sucks!!! I get about 18 average. Mostly city driving. And a leaking gas tank. So, no worries. Oh, and my tach is off by 200 RPMs. It says 2800 at 80 which is actually only 2600. That's with the 3.73.
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Old Jun 6, 2010 | 10:20 PM
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stall converters have a lock up clutch,which acts like a 5 gear.if you do alot a city driving you will lose some mpg.if you want to beat stangs and rice racer,get a 3500 stall and a trans cooler.
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Old Jun 7, 2010 | 12:21 AM
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I just got a 3600 stall and 3.42s installed. On my first fill up I figured that I averaged about 15.7mpg of mixed driving.
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Old Jun 7, 2010 | 05:59 AM
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This is the same thing everyone has been telling me and I dont do a lot of city driving thats why the stall kind of appealed to me I had other threads about it and people were telling me to do gears first and vice versa I was looking at around a 3200 stall because of the 2.73's and the car is a dd so I think that what I'll be looking at here soon.
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Old Jun 7, 2010 | 06:53 PM
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I've also heard that you'd want to upgrade your gears anyway if your going with a stall just because of the stress it adds to your transmission and because driving around with a stall just feels weird with 2.73s compared to higher gears. A few mpgs down isn't going to kill you, I wouldn't worry about it anyway. Thats why you have a V8!
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Old Jun 7, 2010 | 07:09 PM
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Originally Posted by Youshallgofo
I've also heard that you'd want to upgrade your gears anyway if your going with a stall just because of the stress it adds to your transmission and because driving around with a stall just feels weird with 2.73s compared to higher gears. A few mpgs down isn't going to kill you, I wouldn't worry about it anyway. Thats why you have a V8!
agreed. mpg+sports car= no no
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Old Jun 8, 2010 | 06:31 AM
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so true lol but v8+shittympg=less money for college beer fund lol a few mpgs wont matter I'll prolly end up doing the stall first since everyone says it should be the first mod to an a4 lol.
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Old Jun 8, 2010 | 10:21 AM
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Like the others have stated, few have purchased a LS powered F-body for their fuel efficiency.

That being said, the swap from a 2.73 to a 3.42 or 3.73 (which I would recommend) would only have a nominal effect on mileage. Perhaps you get 20 less miles on a tank of gas. If you average 20 mpg (highway), that's one extra gallon of gas at $2.85 you'd have to purchase to go the same distance as before.

I do understand the beer fund as noted above -- that $2.85 equates to a 6-pack of Beast light or Southpaw!
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Old Jun 8, 2010 | 01:04 PM
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dont drive 80 mph and you wont have to worry about the mpg difference.
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Old Jun 8, 2010 | 04:45 PM
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thinking of doing the same thing but my camaro is way better on gas than the 96 mustang i use to have before the z.
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Old Jun 9, 2010 | 05:36 AM
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Originally Posted by 01ssreda4
dont drive 80 mph and you wont have to worry about the mpg difference.
Lol i try not to usually but when Im driving home from college its about a 3 hr drive through the country and if your not doin 80 prepare to get ran over, even the slow lane moves 75+ most people are doin 85-90
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Old Jun 11, 2010 | 11:39 AM
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well guys it looks like the stall may have to come after the gears.... Lol I was at the junk yard today getting a few things with my grandpa when I stumbled up a 98 v6 camaro with the 3.42 and posi option. The car had unknown mileage but the interior had no rips the underbody was clean as hell, the keyless remote looked almost new even the shocks were grease free so I figured it couldnt have had a hell of a lot. Anyway I pulled out the auburn posi and gears and they all look great no cunks missing and the magnet just had regular metal fuzz on it. Anyway I ended up walking out with the ring and pinion along with the auburn carrier for $45 bucks lol so I figured I really cant go wrong even though I'm more of a torsen guys as far as the posi goes.
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