Transmission Gear Ratios and Final Drives

[Sgt.Gator]

I found this on NASIOC. I like it because it includes the final drive ratio along with the years/cars they came in. If you know of any errors let me know and I'll edit it:

 

Factory Gear Ratios for Reference

 

All-Wheel-Drive 5-speed Transmissions

USDM

3.454 / 1.947 / 1.366 / 0.972 / 0.738 / 3.900FD - '02-'05 USDM WRX; 3.545FD rear diff

3.454 / 1.947 / 1.366 / 0.972 / 0.738 / 3.700FD - '06-'07 USDM WRX

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 3.900FD - '08-current USDM WRX

3.454 / 1.947 / 1.366 / 0.972 / 0.738 / 4.444FD - '04-'08 Forester 2.5XT

3.454 / 2.062 / 1.448 / 1.088 / 0.780 / 4.111FD - '04-'13 Forester non-turbo

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 4.111FD - '05-'06 USDM Legacy 2.5GT

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 3.900FD - '07-'09 USDM Legacy 2.5GT

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 4.444FD - '05-'09 USDM Outback 2.5XT

3.545 / 2.111 / 1.448 / 1.088 / 0.780 / 4.111FD - '98-'01 USDM Impreza 2.5RS

3.545 / 2.111 / 1.448 / 1.088 / 0.780 / 3.900FD - '96-'01 USDM Impreza L/OBS

3.545 / 2.111 / 1.448 / 1.088 / 0.780 / 4.111FD - '96-'99 USDM Legacy 2.5GT

3.545 / 2.111 / 1.448 / 1.088 / 0.871 / 4.111FD - '96-'99 USDM Legacy Outback

3.454 / 2.062 / 1.448 / 1.088 / 0.871 / 4.111FD - '00-'07 USDM Outback

3.454 / 2.062 / 1.448 / 1.088 / 0.825 / 4.111FD - '08-current USDM Outback

3.454 / 2.062 / 1.448 / 1.088 / 0.780 / 4.111FD - '02-'04 USDM Impreza 2.5RS/'05 Impreza 2.5RS Sport

3.545 / 1.947 / 1.366 / 0.972 / 0.780 / 4.111FD - '93-'94 USDM Impreza 1.8L

3.545 / 2.111 / 1.448 / 1.088 / 0.825 / 3.900FD - '95 USDM Impreza 1.8L

 

JDM

3.454 / 2.062 / 1.448 / 1.088 / 0.825 / 4.111FD – '93-'96 JDM Impreza WRX/STi

3.454 / 2.333 / 1.750 / 1.354 / 0.972 / 3.900FD – '93 JDM Impreza WRX RA

3.454 / 2.333 / 1.750 / 1.354 / 0.972 / 4.111FD – '94-'95 JDM Impreza WRX RA/STi RA

3.454 / 2.062 / 1.448 / 1.088 / 0.825 / 4.111FD – '93-'00 JDM Impreza WRX Wagon

3.083 / 2.062 / 1.545 / 1.151 / 0.825 / 4.444FD – '97-'00 JDM Impreza WRX RA/Type R/STi RA/22B STi

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 4.444FD – '97-'00 JDM Impreza WRX/STi

3.166 / 1.882 / 1.296 / 0.972 / 0.738 / 4.444FD – '01-'07 JDM Impreza WRX

 

All-Wheel-Drive 6-speed Transmissions

3.636 / 2.375 / 1.761 / 1.346 / 1.062 / 0.842 / 3.900FD

- JDM Impreza WRX Spec C/STi/STi Spec C RA/V-Limted/S202/S203/S204/Spec C RA-R

- AUS Impreza WRX STi

 

3.636 / 2.235 / 1.521 / 1.137 / 0.971 / 0.756 / 3.900FD

- USDM 2007-current Impreza WRX STi

 

3.636 / 2.375 / 1.761 / 1.346 / 0.971 / 0.756 / 3.900FD

- USDM 2004-2006 Impreza WRX STi

- UK/Europe/NZ Impreza WRX STi

- JDM Legacy 3.0R Spec B

 

3.636 / 2.235 / 1.521 / 1.137 / 0.891 / 0.707 / 3.900FD

- USDM 2007-2009 Legacy 2.5GT Spec B

- JDM 2004-2007 Forester STi

 

NOTE: USDM '04/'05 R180 2way clutch type LSD with 3.900FD. USDM '06-current R180 torsen LSD with 3.545FD.

 

The NEW 6 speed MT (NOT the same 6spd tranny as the LGT SpecB/STI)

3.454/1.947/1.296/.972/.825/.695/ 4.444FD -2010 Outback

 

 

Calculators for Speed and RPM, includes tire size and comparison graphing

 

http://www.teammfactory.com/calculator

 

Update 2-2019-I found this useful calculator at SubaruGears. Be sure to click on Calculate, then farther down Auto Shift. It's cool to watch the gauges, it feels more "real" than looking at a graph.

http://www.subarugears.com/Ratios/Ratios.html

 

 

I found this incredibly useful chart at Rallispec. Thanks Rallispec!

"This file provides a means for referencing the original model(s) and gearbox/differential specifications based on the transmission code. It lists gear ratios, transfer gear ratio, final drive ratio, differential types, and some other data. The codes are divided into 4 sections: 6-speed transmissions with 85mm shaft centerline spacing (such as STI), 6-speed transmissions with 75mm centerline spacing (such as newer Legacy manual transmissions), 5-speed transmissions from turbo models (such as WRX), and 5-speed transmissions from normally aspirated models. Only all wheel drive transmissions from Impreza, Legacy, Baja, Forester, and Saab 9-2X models are listed at this time."

http://www.rallispec.com/downloads/Transmission%20ID%20Chart_Public.pdf

 

When you are comparing the tranny to the above Rallispec pdf, use this tag on the tranny:

 

Example 5 speed USDM LGT:

 

 

Example 6 speed JDM Forester STi:

 

Edited February 11, 2019 by Sgt.Gator
Updated with 01-07 JDM WRX

[whitetiger]

Its about time.

[Zack Spec B]

Since i dont know how to subscribe. Gotta read this later tonight

[GEE-OTTO]

Here is the rallispec chart also helpful for cross referencing gearboxes:

 

http://www.rallispec.com/downloads/Transmission%20ID%20Chart_Public.pdf

[whitetiger]

^awesome chart.

[Cincy05LGT]

Anybody find info on the JDM legacy gear ratios?

 

Sent from my Pixel 2 using Tapatalk

[Mr.RMFC]

So in terms of bolting to the engine.

Will a transmission from a 2011 wrx bolt up to my 2005 legacy gt? Will the mounts all match? I have the rear dif to go with it so the ratios will all be the same.

Is the speedometer based off of wheel speed or is it a sensor somewhere else?

Will I see a change in mpg on the highway with the wrx trans?

Swapping due to needing a new trans

[whitetiger]

it will bolt up. make sure you use the 2011 wrx clutch and associated hardware. speedo is from the wheel speed sensors. MPG difference will be negligible.

 

go for it.

[Kaden]

Anyone know what year sti 6 speed trans will fit on my 1998 legacy gt Sedan 2.5L DOHC it’s turbo’d

[cooki3monst3r77]

Does anyone know how to determine the front or rear gearbox gear ratio?

[awfulwaffle]

Find the model number sticker on the side of the trans, then find it in this chart (also in Sgt. Gator's original post above). That, or just find what came with your year/model if the trans is original and find it in the chart.

 

https://www.rallispec.com/downloads/Transmission%20ID%20Chart_Public.pdf

 

Or, open er' up and count teeth.