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Discussion Starter #1
Okay guys, I'm in desperate need of advice! I am toying with the idea of putting 3.73 gears in my car (crazy I know, lol). I have several hang ups so to speak. For starters I am 17 which doesn't leave me with much extra money for tires and gas, secondly how much will it kill my mileage? I GET IT, its a hot rod and it shouldn't matter but this is my daily driver and I frequently go on long road trips so I don't want to be getting less than 15 mpg hwy. The car is a 1991 LX 5.0 5 speed. Gt40p heads, gt40 intake, xe270hr-14 (.512./.512 218/224 @.050 114 lsa i THINK) she has the stock 2.73s (don't laugh) and I'm just curious if ill reap the benefits of a shorter gear without losing all of my mileage. I know ill take a hit but i don't know how bad it will be. thanks! :grin2:
 

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Discussion Starter #3
Start by verifying current gear. That will help guess how gear change will effect you.

A simple video off youtube on how to check in case you didn't know already.

https://www.youtube.com/watch?v=QisQfYmN0ng

I marked the driveshaft and turned the tires once and the driveshaft spun 2.73 times. I guess the biggest hangup is economy for me. I can't be getting 10 mpg :frown2:
 

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3.73s are not that crazy if you ask me. I had 3.73s in my old 88 GT and I drove it as DD for a while. 15 MPG probably is pushing it. I agree with the guy above - 3.27 would be a great compromise. You can still spin plenty of tires with 3.27s. 3.73s was a bit much for a DD in my opinion.
 

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Had 3.73s in my old 93 and 3.55s in my current 92. Like the 3.55s much better. First gear is too short for a daily with 3.73s IMHO. I honestly didn't notice a mileage drop with the gear swap. I am pretty convinced that mileage is a factor of weight (for around town driving) and aerodynamics (for highway use) and the specifics of engine size/rpm don't make all that big of a difference. But that's just me and others will probably disagree.
 
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