January 29, 2013
Once underway, AWD loses its immediate traction advantage, which is why many AWD systems direct power only to the front wheels when underway, and only distribute power to all four wheels when there is a traction crisis. For the record, Subaru’s Symmetrical AWD system sends power to all four wheels all the time, which comes at the expense of fuel economy, but never has to hesitate when losing traction. Although it can help with cornering and braking through throttle applications and engine braking, a vehicle’s chassis and the tires’ grip are bigger factors in how a car will handle in the snow. Can the Legacy’s chassis match its AWD traction? It was time to find out.
We had two versions of the Legacy, the 2.5i and 3.6R, to compare against a base Honda Accord LX and base Toyota Camry LE. We drove them to the limit, and sometimes beyond, through several winter tests that included a snow slalom, snow/ice skidpad, short snow track, long snow track, and braking tests. First up was a snow slalom ending with an emergency lane change maneuver. The Subaru Legacy was pitted against the Toyota Camry for this test. As should be expected, the Legacy was able to leave the line much faster than the Toyota thanks to the AWD system. However, once it reached the set of pylons used for the slalom course, the initial response to turning the wheel and cornering grip provided by the front tires of the Legacy was far more readily available than the Camry’s. Whereas the Camry felt slow to respond and unsettled, the Legacy’s reactions were very immediate and controlled. This had as much to do with all-wheel drive as chassis setup.
Comparison Test: AWD vs FWD Family Sedans on Ice. Click image to enlarge
However, once the slalom was completed, there was a last-second emergency lane change maneuver. This required stabbing the brakes, which would activate the antilock braking system, then turning hard left or right to simulate dodging another vehicle or obstacle in the road. Here, we were completely off the throttle so it was all up to chassis, brakes and steering to dictate how successfully the vehicles went through. Once again, the Legacy not only responded to inputs quicker but was able to achieve the emergency lane change maneuver more quickly and with less drama. One of the main reasons the Camry is reluctant to change direction is that it has a far larger percentage of its weight hanging over the front tires. This makes it even more prone to initial understeer (going straight even when you turn the steering wheel, or just not turning as much as you want) than the Legacy, which was apparent in this test. As well, the Legacy has perfect weight distribution side to side and a suspension set-up better suited for this all-important maneuver, whether out here on this carefully managed testing site, or out in the real world in the worst conceivable conditions.
One of the biggest surprises for all of us during this test was just how willing the Toyota Camry is to oversteer (back end trying to swing around past the front end) after the initial wave of understeer. Time a corner right, carry in your momentum properly, and the rear end will pendulum around more than the Legacy’s or Accord’s. The Camry’s love of oversteer actually made it fun to drive around the ice track; yes, I just said ‘fun to drive’ and ‘Camry’ in the same sentence. However, the Camry was the poorest to bite into corners and slowest to respond to inputs. It was easy to get the Camry’s chassis upset, which was fun for me in this testing environment, but would be downright frightening for the average motorist; thank goodness there is stability control.