Subaru's 40th - four decades of AWD

Congratulations to Subaru for achieving the milestone of forty years of true all-wheel-drive!

Today’s “AWDs” are really often front wheel drives, with on-demand AWD – the back axle only kicks in when traction is lost on the front.   This is done for fuel efficiency, but can you spot the flaw? Traction has to be lost first, and while you can make it as instant as you like, it’s still a traction loss and in some cases once a loss begins it cannot be stopped.Furthermore, had all four wheels been driving in the first place then maybe the loss wouldn’t have occurred.  Subaru’s AWD power all four wheels, all the time, equally, 50/50 front and rear.  Aside from traction benefits that’s also a handling improvement too, reducing the front wheel drive understeer you can find on the likes of the XC90 to name just one.

 The “symmetrical” part goes further than just the 50/50 split.   The driveshafts on both front and rear axles are the same length, so have the same drag and thus have equal torque losses.   The engine is also symmetrical, so the car starts out evenly balanced with its heaviest components.

 All this sounds like a Subaru advert, but it’s not.  Technology is marching onwards, and a constant 50/50 torque split front and rear isn’t always the way to go.  I don’t agree with 0% torque to the rear wheels for the reasons above, but it may well be sensible to bias torque front or rear according to the conditions, as can now be done with computer-controlled torque splitters in place of the primitive viscous couplings of old.    The symmetrical design advantages also being eroded with the passage of time, although they remain an advantage. Subaru has of course kept pace, and they now use electronically controlled systems too.

But it’s still good to see Subaru still there after 40 years, delivering cars everyone loves.  Subies have resale values the envy of the industry, and they’re the vehicle of choice for recreational people that don’t want more specialised offroader.  It’s also good to see them hold to their core values, unlike say Land Rover who offer 2WDs, BMW who are considering FWD and so on.  Every offroader has a soft spot for a Subie, and here’s to another 40 years!

There's just one question - Su-bar-ru or Soober-roo?