Thanks goes to jimqpublic for putting this together.

Thanks Jim :)

-------------------

From page SPC3 of the service manual:
2.5L non turbo manual trans has 4.11:1 final drive
Non-turbo AT and Turbo manual and AT all have 4.44:1 final drive.

Side Note- The VTD automatic transmissions in the WRX, Legacy GT, 6 cylinder Outbacks, and in the future Baja Turbo have different final drive ratios in the front and rear differentials. This is because of the way the transfer case splits torque which results in the front and rear driveshafts spinning at different rates. The differentials have compensating ratios so that the wheels all turn at the same rate. (Oh how I wish the XT had the VTD system).

2.5 Non Turbo 5 Manual
1st 3.454
2nd 2.062
3rd 1.448
4th 1.088
5th 0.780
Reverse 3.333
Transfer 1.000
Final 4.111

2.5 Non Turbo 4 Auto
1st 3.027
2nd 1.619
3rd 1.000
4th 0.694
Reverse 2.272
Transfer (none)
Final 4.444

2.5 XT Turbo 5 Manual
1st 3.454
2nd 1.947
3rd 1.366
4th 0.972
5th 0.738
Reverse 3.333
Transfer 1.000
Final 4.444

2.5 XT Turbo 4 Auto
1st 2.785
2nd 1.545
3rd 1.000
4th 0.694
Reverse 2.272
Transfer (none)
Final 4.444


The XT manual has the shortest first gear and top gears while the XT automatic has the tallest first and top gears of the four available Forester transmission/final drive combinations. Assuming the automatic with lockup torque converter is pretty efficient, it would theoretically give better mileage due to lower cruising rpm's.

The Automatic in the non-turbo models has an average sea level stall speed of 2450 rpm's vs. 2950 rpm's for the Turbo per page 4AT-2. Somewhere in the manual I read that the torque multiplication effect at stall is slightly over 2:1, but I can't find it now.

If someone knows the effective rolling diameter of the tires, you can figure rpm at specific speeds.

Taking those numbers, the first and top gear reduction ratio (gear X final drive) is:
2.5 Non Turbo MT First: 14.20 Top: 3.21
2.5 Non Turbo AT First: 13.44 Top: 3.08
2.5 XT Turbo MT First: 15.34 Top: 3.28
2.5 XT Turbo AT First: 12.38 Top: 3.08


To figure maximum first gear launch torque at the wheels, I've assumed that the manual trans models are running at a non-clutch-abusive 2000 rpm's, then again with a clutch abusive max engine torque launch of 3600 rpm's at the engine torque peak. Auto trans torque values are at TC stall speed. Torque values interpolated from small plots in subaru.com.au's Forester and Forester XT tech publications 929304.pdf and 929305.pdf. I've assumed zero drivetrain losses, so these numbers are good for comparison only, not planning your next bank robbery getaway.

These calc's were related to getting my camping trailer moving on a hill, not drag racing. Drag racers would probably sidestep the clutch at 7000 rpm's and call it non-abusive.

Non-turbo advertised crankshaft torque:
195 NM at 2000 rpm
200 NM at 2450 rpm
223 NM at 3600 rpm (peak, although older US spec's had the 2.5 liter engine peaking at 4400)

Turbo advertised crankshaft torque:
255 NM at 2000 rpm
295 NM at 2950 rpm
320 NM at 3600 rpm (peak)


So... the envelope please...
2.5 Non Turbo MT non abusive: 2769 NM
2.5 Non Turbo MT Abusive: 3167 NM
2.5 Non Turbo AT: 5376 NM

2.5 XT Turbo MT non-abusive: 3912 NM
2.5 XT Turbo MT Abusive: 4908 NM
2.5 XT Turbo AT: 7300 NM

That's a lot of fig newtons.

Although it appears that the XT Auto delivers a lot more wheel torque from a standstill, Dempsey aka "turbominivan" has reported that the auto version doesn't deliver boost when brake torqueing. That means less engine torque and less go.

RPM VS Speed (MPH) For the Forester XT MY 2004.