3:08 to 3:73?

Mark99gt · 06-30-2000, 12:45 PM

does anyone know the mpg loss from changing from the stock gt 3:08's? to the 3:73s? Im hoping it isnt more then a loss of 2 mpg since I travel a lot of highway miles.

Also with the speedo being offset, what is the best and cheapest way to correct this? How much? Thanks for your help in advance.

95GTS · 06-30-2000, 03:55 PM

Depending if you have an auto or not. With 5-speed you can still milk the mpg. If you are easy with the car and don't play alot with it your mpg's shouldn't change. I averaged 22mpg/tank with the 2.73s and now with 3.73s I still get 22mpg/tank. I get also get alittle better mpg in town but not quite as good on the highway but still can get mid 20's mpg at 70 mph. though my car is a bit lighter too which also helps. A 23 tooth speedometer gear ($15) corrected my speedo up to about 60-65 mph then it's a little off (by about 5 mph). You'll like the 3.73s. I had 3.55s in before the 3.73s and like the 3.73s a bit better. I do alot of driving too, highway and in town. Don't worry about the gas mileage. It's really not going to get hurt. Unless you play with the car alot.

------------------
1996 Mustang GTS: 5-speed, K&N, removed air silencer, 3.73s, turndowns after stock H-pipe (no mufflers)

[This message has been edited by 96GTS (edited 06-30-2000).]

Mark99gt · 07-04-2000, 08:33 AM

Thanks for the reply. Yep I have a 5 speed but Ive read on a few places that the 99 and 00's need to get a computer controlled speed compensator.. Ive heard of Abbott Speed Compensator but havent been able to find it to buy it. Im just wondering if a Superchip can do the same thing as this compensator because they dont need me to tap into any wires. Does anyone out there know of any other things to correct the speedo on a 99 gt?

------------------
99 GT convertable, 5 Speed, K&N w/silencer removed.

Black99GT · 07-07-2000, 08:08 AM

Mark,
I thought 3.27's was stock for 99. Mine came stock with 3.27's.Are you sure you have 3.08's? Maybe its a vert thing?

------------------
Black 99 GT
3.73 gears
Mac power chamber
2 chamber Flows
Mac cold air induction
steeda tri-ax
Nitto drag radials
13.62 @ 109 (using a G-tech pro)
http://www.mustangworks.com/cgi-bin/MediaDL.cgi?Home_Video+movies+Black99GT-burnem+mpg

97snakedriver · 07-07-2000, 10:21 AM

Try Sean Hyland Motorsports for the compensator. I went from 3.27s to 4.10s and I still get good milage. I have gotten as high as 26 mpg on the interstate.

------------------
1997 Cobra
Suspension: Steeda G Trac. Tokico Illumina shocks and struts, Sport Springs, upper and lower control arms, cc plates, rear adjustable sway bar, front sway bar, subframe connectors, bushings, Cobra R wheels

Exhaust (soon): FRPP ceramic headers, Bassani X-pipe w/ cats, Dynomax Ultra Flow cat-back

Bolt-ons: 4.10s, Steeda Tri-Ax, Pro-M 80mm, K&N, Steeda Underdrive pulleys, Steeda timing adjuster (soon)

Mark99gt · 07-07-2000, 03:23 PM

yep its 3:27s stock. I originally thought they were 3.08s, my mistake....Only thing holding my back on gears is if and if so where and how to correct the speedo if I change gears. Im wondering if the dealer would change the speedo if I had them install it... btw I should have my steeda tri-ax shifter Monday.

Ch4nce · 07-08-2000, 12:33 AM

You can get the abbott speed compensator from Houston Performance for $120, it works really good....
http://www.houstonperformance.com

------------------
1999 Mustang GT 35th Anniversary Edition
- FMS 3.73 Gears
- Abbott ERA Speed Compensator
- Steeda Tri-Ax Shifter
- MAC Cold Air Induction Kit
- K&N Air Filter
- 2 Chamber Flowmaster Mufflers
- Mustang World Bumper Inserts
14.27 @ 97MPH on stock Goodyear ZR45 radials
http://ch4nce.modularstang.com
ch4nce@yahoo.com

06-30-2000, 12:45 PM	#1
Mark99gt Registered Member Join Date: May 2000 Posts: 9	3:08 to 3:73? does anyone know the mpg loss from changing from the stock gt 3:08's? to the 3:73s? Im hoping it isnt more then a loss of 2 mpg since I travel a lot of highway miles. Also with the speedo being offset, what is the best and cheapest way to correct this? How much? Thanks for your help in advance.

06-30-2000, 03:55 PM	#2
95GTS Git jiggy Join Date: Oct 1999 Location: MO USA Posts: 865	Depending if you have an auto or not. With 5-speed you can still milk the mpg. If you are easy with the car and don't play alot with it your mpg's shouldn't change. I averaged 22mpg/tank with the 2.73s and now with 3.73s I still get 22mpg/tank. I get also get alittle better mpg in town but not quite as good on the highway but still can get mid 20's mpg at 70 mph. though my car is a bit lighter too which also helps. A 23 tooth speedometer gear ($15) corrected my speedo up to about 60-65 mph then it's a little off (by about 5 mph). You'll like the 3.73s. I had 3.55s in before the 3.73s and like the 3.73s a bit better. I do alot of driving too, highway and in town. Don't worry about the gas mileage. It's really not going to get hurt. Unless you play with the car alot. ------------------ 1996 Mustang GTS: 5-speed, K&N, removed air silencer, 3.73s, turndowns after stock H-pipe (no mufflers) [This message has been edited by 96GTS (edited 06-30-2000).]

07-04-2000, 08:33 AM	#3
Mark99gt Registered Member Join Date: May 2000 Posts: 9	Thanks for the reply. Yep I have a 5 speed but Ive read on a few places that the 99 and 00's need to get a computer controlled speed compensator.. Ive heard of Abbott Speed Compensator but havent been able to find it to buy it. Im just wondering if a Superchip can do the same thing as this compensator because they dont need me to tap into any wires. Does anyone out there know of any other things to correct the speedo on a 99 gt? ------------------ 99 GT convertable, 5 Speed, K&N w/silencer removed.

07-07-2000, 08:08 AM	#4
Black99GT Registered Member Join Date: Jan 2000 Location: New Oreans Posts: 133	Mark, I thought 3.27's was stock for 99. Mine came stock with 3.27's.Are you sure you have 3.08's? Maybe its a vert thing? ------------------ Black 99 GT 3.73 gears Mac power chamber 2 chamber Flows Mac cold air induction steeda tri-ax Nitto drag radials 13.62 @ 109 (using a G-tech pro) http://www.mustangworks.com/cgi-bin/MediaDL.cgi?Home_Video+movies+Black99GT-burnem+mpg

07-07-2000, 10:21 AM	#5
97snakedriver Registered Member Join Date: May 1999 Location: Blacksburg, VA Posts: 1,526	Try Sean Hyland Motorsports for the compensator. I went from 3.27s to 4.10s and I still get good milage. I have gotten as high as 26 mpg on the interstate. ------------------ 1997 Cobra Suspension: Steeda G Trac. Tokico Illumina shocks and struts, Sport Springs, upper and lower control arms, cc plates, rear adjustable sway bar, front sway bar, subframe connectors, bushings, Cobra R wheels Exhaust (soon): FRPP ceramic headers, Bassani X-pipe w/ cats, Dynomax Ultra Flow cat-back Bolt-ons: 4.10s, Steeda Tri-Ax, Pro-M 80mm, K&N, Steeda Underdrive pulleys, Steeda timing adjuster (soon)

07-07-2000, 03:23 PM	#6
Mark99gt Registered Member Join Date: May 2000 Posts: 9	yep its 3:27s stock. I originally thought they were 3.08s, my mistake....Only thing holding my back on gears is if and if so where and how to correct the speedo if I change gears. Im wondering if the dealer would change the speedo if I had them install it... btw I should have my steeda tri-ax shifter Monday.

07-08-2000, 12:33 AM	#7
Ch4nce Registered Member Join Date: Apr 2000 Location: Richmond, VA Posts: 21	You can get the abbott speed compensator from Houston Performance for $120, it works really good.... http://www.houstonperformance.com ------------------ 1999 Mustang GT 35th Anniversary Edition - FMS 3.73 Gears - Abbott ERA Speed Compensator - Steeda Tri-Ax Shifter - MAC Cold Air Induction Kit - K&N Air Filter - 2 Chamber Flowmaster Mufflers - Mustang World Bumper Inserts 14.27 @ 97MPH on stock Goodyear ZR45 radials http://ch4nce.modularstang.com ch4nce@yahoo.com