Gear swap/MPG change?

[BANGERSTANGER76]

Hey guys.

Does a gear swapp hurt the MPG?

 

[VibrantRedGT]

If you bought a Mustang for MPG's you got the wrong car. Find your nearest Honda dealership.

A gear swap depending on what gear will move RPM's up. Rule of thumb each time you move up its about 275rpm. Example-say with the 3:27's at 80MPH your at 2000rpm. With 3:55's you'll move to 2275rpm, with 3:73's 2550rpm, etc. Then you add in shift points and not beating on it.

 

[95snoozer]

higher rpm on highway =/= mpg loss.

Your fuel usage is based off of the amount of fuel you are using. to make the 12-15 hp it takes to actually drive your car at 70 mph.

Gearing is a very small part of that equation. 90% of mustang owners dont grasp this. Its basicly the way a prius works. Tiny motor that is efficient at highway speeds use for holding the car at a steady speed and get maximum mpg.

having higher numerical gears can actually improve in town mileage if you can keep your foot out of it and use hypermileage shift techniques.

Friends and I have gotten stock mpg and better with 3.73s and 4.30s. Plenty of mach 1s out there doing 26 mpg with 4.30s


Tire PSI and The weight of your car is going to be a big factor. If you really need mileage, get big and little prostars. with 40+ psi in the front tires. drop as much weight as possible, then remove your mirrows and windshield wipers and masking tape your seams in your front bumper....

Better do the short antenna mod too. Thats at least .01 drag coefficient.

http://ecomodder.com/forum/tool-aero-rolling-resistance.php

 

[BANGERSTANGER76]

If you bought a Mustang for MPG's you got the wrong car. Find your nearest Honda dealership.

A gear swap depending on what gear will move RPM's up. Rule of thumb each time you move up its about 275rpm. Example-say with the 3:27's at 80MPH your at 2000rpm. With 3:55's you'll move to 2275rpm, with 3:73's 2550rpm, etc. Then you add in shift points and not beating on it.

No I got the exact car I wanted.
Everyone on this site does not want a 600 hp gas guzzling beast!!!!
I have 2 other old schools that are monsters. Plus a truck. So I know plenty about gas guzzlers. I'm making upgrades on my Stang for extra horse power but I do not want to alter the MPG too much in the process. I heard gears will severely alter gas milage. I drive this car alot so no gas guzzling. If I want to see 500 hp Ill come on here and read about you boys super Stangs. Thanks for the input. Much appreciated.

 

[95snoozer]

I heard gears will severely alter gas milage. I drive this car alot so no gas guzzling. If I want to see 500 hp Ill come on here and read about you boys super Stangs. Thanks for the input. Much appreciated.

100% false

driving habbits, tire pressure, tuneup status greatly effect mpg.


I did get 15 mpg the week after i installed my Heads Cam Then I got 24 once I relaxed.

 

[revhead347]

If you go to a 3.73:1 or something like that, it usually hurts you a little on the highway, and helps around town. It's usually a wash for most people, since most people do a mix of driving. If you do a ton of highway driving, then you'll lose a little. It's definately not a huge difference, so long as you don't get something like a 4.56:1 gear ratio. You're talking 1....maybe 2 mpg.

Kurt

 

[BANGERSTANGER76]

100% false

driving habbits, tire pressure, tuneup status greatly effect mpg.


I did get 15 mpg the week after i installed my Heads Cam Then I got 24 once I relaxed.

I cant blame you. I get the ANVIL foot from time to time myself. LOL
Right now the car is running very nice.
New everything. now Im just trying to find extra areas to attack. I dont even know what my stock gears are????? I may go with some 3.55 or something like that. Not too much not too little. I do alot of highway driving so i most def dont want to affect that MPG too much and Im going with 20 inch rims as well.

Thanks again for the replies. You boys are insane with the Stangs.

 

[Three50won]

@ BANGERSTANGER76...all engines have an rpm where they are at their most efficient. So if you installed a numerically higher gear set and did all highway driving and that gear set put you in the range where the engine is most efficient, then it's possible you could see an improvement in gas mileage. If you're doing a lot of city and stop/go light to light driving then you will get lower gas mileage. I have 4.10s in my 03 and I'm having 3.73s installed in my 95 next week. The gas mileage is bearable to me. Besides, you could always retard the timing or detune the ECU to run 87 octane and offset the difference. Or do some other mods that are known to increase gas mileage (UDP's, CAI, exhaust...) and that'll also help. When all is said and done you might actually gain MPG's!!

 

[5spd GT]

Hey guys.

Does a gear swapp hurt the MPG?

Don't worry about the poor attitudes. I own a Honda and a H/C/I stang, but I still care about MPG if I can get it.

When I had my stock '93 notch, my OD went out. The stock AOD with 3.27's in Drive (not OD) sits at 2700-2800 RPM at 55 MPH.

This is annoying on a stock engine. My gas mileage took a 40-45 MPG hit per tank and the engine ran warmer.

More RPM = More fuel = More friction = More heat

However, in my experience, putting steeper gears on a stock induction engine (ex. 4:10's vs. stock 2:73's) this can hurt the MPG on the highway. On the flip side, a better breathing engine will benefit in MPG with a gear change of the same accord. Now this can be negated with sustained high RPM cruising, like I experienced above.

It is just like I gained 3 MPG when I did a h/c/i swap. My car was much more efficient getting around and did not have to work so hard.