Worth changing gears to imporve Fuel Economy?

[garys_1k]

Hmm, I don't know if an aftermarket shift point recalibration tool is available. I'd guess there is, given the popularity of Mustangs and the interest in performance modifications.

Again, though, if you did swap the axle you'd be guaranteed a nice highway FE boost, and even without a recalibration you'd at worst stay about even in around town driving. I'd go for it if you did at least 1/3 of your driving on the highway.

[lovemysan]

I would think that 2.73s would be fine. The 3.8 makes plenty of torque.

[Tony Raine]

how can I improve acceleration without using 2GPH at 1365RPM when staring off at a dead stop without hitting the accelrator hard at all.

getting taller gears will make this worse. lower gears multiply torque (at a lower rpm) to make it easier to get moving.

Would changing my Mustang's stock 3.27 rear gears to 2.73 increase my fuel economy and by how much possible?

i would count on about a grand+ to have someone swap the gears. (cost of gears, installation parts, oil, labor, speedometer correction, etc....). think you'll get enough out of this mod to pay for/profit from it? it will probably only drop your cruising rpm's by around 450. you can lower your rpm's a little by buying a little bigger tires for the rear once your stock ones wear out. (i got 2" bigger tires and dropped my cruising rpm by around 250.) but then you still have to correct the speedometer/odometer ( i just calculate after-the-fact).




lets say you get a 2mpg highway boost with the gear swap. assuming 15,000 (highway-only) miles a year and 3.90 for gas, you'll save $161 a year. so it will take around 7 years just to pay off the mod.

worth it? i'd say no. but thats just my opinion, which with $0.50 will buy a cold cup of coffee. if you still want to go through with it, you may be able to find an entire axle from another 'stang and swap it in. (unbolting an axle and bolting in another identical one is 1000X easier than attempting a gear swap youself). you may even find someone that will trade axle-for-axle because they want the lower gears.

[whokilledthejams]

If you can get a decent 2.73 rear axle for cheap (which I can't see being too hard), swapping out an entire axle is something you could do in a day in your driveway. Bribe a trustworthy friend with beer and pizza, and you're in business. Of course, I say trustworthy, because you don't need an axle dropped on your skull.

As for shift points, is it an electronically controlled transmission? If it isn't, it's probably not too hard to adjust, as it would all be mechanical adjustments. Again, something you could do in the driveway.

[Schwaebz]

for your case, i say you start here

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this is where you should mingle lol

[Schwaebz]

wikipedia

[dcb]

re: costs, if you are a do-it-yourselfer AND you know what prussian blue is (not the little singers from hell), then you can probably pluck some better gears out of a boneyard rearend for like $20.

[Schwaebz]

lol, if its a GT that the op has, i will slap you for trying to through a 7.5 on there, i frankly woulkd try other options for your car. try lighting it up, throw a dual exhaust on it, a CAI, under drive pullies, lower it, get some nice wheels on it


and bam, you'll have a decent car


plus, you will somehow have to re calibrate the car, since it will be a different gear ratio, which costs a lot of money

i say, go to the website i gave you, and give in to the dark side of the force

[dcb]

Dual exhaust for MPG?!? I'm goin to say "try the friggin search button" at this point in the discussion

But If I didn't want to pay for a new car and title and crud, I would swap the rearend gears and put in a stickshift all with the lowest ratio I can find, but no way I would pay someone to do it. Fortunately a lot of performance bent folks will just about give that stuff away.

[Blue07CivicEX]

So... why aren't you out racing people, burning your tires, playing 80's hair bands and getting laughed at by all the people on this site instead of trolling "hippy" forums to make fun of people trying to save a buck? The world is full of people that like to spend their money elsewhere then in the gas tank, people have kids, mortgages, other hobbies they would prefer to spend their money on.

In closing, don't be a dick, if you're here to troll find a better hobby, I'd rather be considered a hippy then be considered whatever you think you are.