True AWD

BMW xdrive.

snipped-for-privacy@canada.com

Not all Subaru's are. Manual tranny versions are, many automatics are, but some automatics are just like the Murano.

Could you elaborate?

The best layman's terms explanation I've seen:

The key theory is that the manual transmission version is using a

50/50 power split, front to rear, much of the time. The automatic sends most (90/10 has been mentioned elsewhere, but I'm not sure of the exact numbers) of the power to the front wheels when the car is on a good footing.

Barry

Manual subarus have a 50/50 power split f/r. Automatics are 90/10 f/r with the ability to vary it based on conditions and slippage. Doesnt mean its not AWD.

You guys are not up-to-date. The 90/10 business went away quite some time ago. There are three AWD systems now, one for manual, and two for automatic. None are 90/10.

Well... mine was 90/10 when I bought it. SO unless the little Subaru Upgrade Fairies snuck in my garage and replaced my tranny and AWD some warm summer night, I suspect it's still 90/10.

NEW Subarus might have something different. But a lot of them on the road are still operating on the old stuff.

Subaru's web site has a lot of great info that is fairly in-depth about it. I suggest starting there to find out what the new cars have on them.

I think the new ones (WRX, anyway) are around 70/30 to 60/40.... the STi is driver variable between 50/50 to 70/30... don't quote me on those numbers though.

Some of the Subaru automatic tranny AWD systems use an electronically controlled transfer case rather than a mechanical center differential. This was mentioned in the Forester tire replacement thread a few days ago.

Here we go again . My '02 VDC H6 splits 54.55 rear and 45.45 under normal driving conditions with friction between front and rear equal (this comes directly from the Subaru technical manual). John

Subaru SOA and Subaru of Altrailia says my 2000 Forester 4EAT has a default ratio of 60 front and 40 rear. 90/10 went out of style about

More to the point of the OP question, with the 5MT Subaru transmissions, the front and rear drive axels are actually physically connected all the time, through a viscouse coupler. So yes, even with the ignition off, if you turn one wheel the other three turn aswell.

The WRX is still 50/50 with an LVCD. The STi is 65/35 Rear bias. The DCCD selects how open the differential is. It doesn't actually vary the torque split I can assure you (drive it on ice and you will KNOW it is not a 50/50 split). However, with the DCCD set to LOCK, the differential will lock up and does not need to detect wheel-spin before locking. With it set in AUTO, it will lock up the centre diff when it detects wheel-slip. However, it is pretty slow to do it on ice. I leave it in LOCK if the roads are really bad, or put it in LOCK to start, and switch it to AUTO to cruise.

My US MY 2000 (Japanese MY 1999) Impreza 2.5 RS automatic has a 90/10 split with a limited slip rear differential. It makes for some interesting driving in the winter if you don't add some weight to the rear end. Thank god the first snow I drove it on was in an empty parking lot.

Nothing like having most of the power transfered to the rear and then to just one tire. I've carried 50 lbs of sand in the trunk during the winter ever since.

I believe with the Impreza redesign the automatics went to 55/45.

Edward Hayes wrote:

Actually, they are connected with a geared differential with a viscous coupling in parallel to minimize slip.

Yes, but it is the VC that makes the two shafts turn together. With no VC, if the transmission is in neutral, then the differential just spins and the front shaft doesn't turn. If the transmission is in gear, I think the front wheels will turn in the opposite direction!

Actually, you are partially correct. A typical Forester does not have LSD's in the front of rear. Assuming all wheels are off the ground, if you turn one back wheel, the other back wheel will turn backwards and the drive shaft wont spin. The same goes for the front wheels. However, if you rotate the rear driveshaft, the front driveshaft will rotate backwards with a center diff. and no viscous copuling and will rotate the same direction as the rear driveshaft with a viscous coupling or a viscous coupling in parallel with a center diff.

For US models, I think X has an open diff in back, while XS & XT have a rear LS diff.