There are few bad things you can say about the AWD platform. It's heavier. And sure, mistakes are more expensive. There're a couple of extra differentials to go bad. Two more axles to break. A transfer case that can fail. And sophisticated electronics like the EVO's Active Yaw Control that most of us would rather not discover the inner workings of prematurely. But if you can keep things together, there's really no all-around better drivetrain out there. There are also more fluids to spend money on. But if you're worried about things like the cost of an extra two quarts of gear lube, then chances are you've got no business driving such an advanced piece of machinery in the first place. Oh, and there are slightly higher drivetrain losses since torque must be distributed to two more places. Details. But the AWD drivetrain isn't the cure-all for an otherwise crappy driver some would believe it to be. No, if driving skills are your problem then it really doesn't matter what you're in. Nevertheless, AWD vehicles measure up differently depending on what you compare them to. The mid-engine, RWD configuration sports car, for example, has the theoretical advantage on the road coarse. Its polar moment of inertia allows it to handle corners in ways other drivetrain-equipped vehicles can only imagine. But winning often boils down to who's driving, which makes all of this theoretical anyways. The AWD platform clearly has the advantage in terms of grip and safety though. Since cars like the DSM, EVO, WRX and STi are based off of FWD platforms, they tend to understeer a bit - not a good thing when considering the race track - but a characteristic that keeps more than a few inexperienced drivers from losing control and careening into things like curbs, brick walls and other cars. As far as straight-line acceleration is concerned, AWD wins here. There's simply no better way to apply traction to the pavement than with all four corners.
The system is really smart if you stop and think about it. Somewhere along the line somebody took a look at the FWD layout, quickly realized pushing's much more effective than pulling, decided to lean toward a RWD configuration but at the last minute decided to combine the two - sort of. Cars like Subaru's WRX and STi and Mitsubishi's DSM and EVO are more FWD than they aren't. In fact, if you were silly enough, you could take an old AWD Eclipse transmission, weld up the center differential and eliminate all that transfer case, driveshaft and rear end nonsense behind it, essentially making it a FWD again. But you wouldn't do that. To convert it to RWD, one would need to relocate the engine by spinning it around 90 degrees and come up with an entirely different transmission to bolt up. DSM guys have been doing this for years, but it's easy to see it's not exactly natural progression for such a vehicle.
No matter the AWD platform's origination or even what other configuration it's more similar to. It doesn't really matter. Today the AWD is its own beast. Taming an STi or an EVO is so much different than learning how to corner in a Miata or an Integra Type R for that matter. It can be a bit of a new learning curve, especially in terms of testing an EVO's traction limits ... in the rain. And with powerplants like Subaru's EJ25 and Mitsubishi's refined 4G63, it's no wonder both the STi and EVO have become the ones to watch out for and is enough to make the choice to side with lesser drivetrains all the more tough. As such, enjoy Turbo's dedicated all-wheel-drive issue; a tribute, if you will, to four-wheeled homologation we've all fallen for.Aaron BonkTech Editor