All-wheel-drive vehicles, on the other hand, are what you might call “full-time AWD.” You can’t turn the system on or off, and there’s no low range; rather, it’s always monitoring traction at all four wheels, ready to transfer power at a moment’s notice in the event of a traction shortage. Every AWD vehicle has a default torque split, meaning the percentage of power that goes to the front and rear axles, respectively, when there’s full traction all around. A common split is 90/10 on dry roads, with up to 50/50 available as conditions dictate. Some crossover SUVs even let you lock the split at 50/50 if you need to. But there’s no rule of thumb here. What the systems have in common is their ability to re-route power from axle to axle (and frequently from side to side as well) when traction is compromised.