[ShadeTreeMech]

depending on the vehicle and type of steering the toe setting will be different.

On rear wheel drive you want a bit of toe in since the wheels will be pushed to closer to a zero toe setting as the vehicle is driven. As parts wear, the actual toe setting while being driven will head toward the toe out.

On front wheel drive, toe out is desireable since the wheels will be forced to toe in somewhat under acceleration. Due to the tendency of front wheel drive to understeer, it also helps to lower the tire wear on the outside of the tread.

On AWD it varies from one car to the next, depending on which is most likely to be the main drive axle. Some older Subarus had front wheel drive with rear wheel drive in 4wd mode, so I would expect a tendency to be set up more as a front wheel drive vehicle.

If you have zero toe, and your steering components are in good shape (no slop in the tie rod ends, ball joints, or upper strut supports) you toe while driving should remain mostly static. But it will feel like the rear of the car wants to spin out of control, and the steering will be very touchy. your tire wear will be excellent, but a different driver of said vehicle stands a good chance of have a one vehicle wreck. I had a Ford Escort with good tires and a perfect alignment with good steering components. Going around a corner that is easily done at 50 with my minivan felt like I was about to lose control. I adjusted to have 1/8th an inch of toe out and it totally changed the driving feel of the car. The steering was still crisp, but the extreme feel of imminent oversteer was gone. I could go around the corner much faster with confidance and without squalling the tires.

If you don't live in an area with a lot of curves in the road, I would highly recommend a zero toe, since it would surely increase fuel economy and tire longevity. For straight line driving it is the optimum setting. But if where you live there are hills and high speed curves, you will prefer the factory settings.

FYI I studied (and passed) a course in suspension, steering and braking last year, so this is a subject I'm very familiar with. I haven't needed to go to an alignment shop for about 2 years now; using a tape measure and basic hand tools I can get an alignment that is within 1% of spec of what a good shop would do. Anyone with the willingness to learn the ropes and patience to do a good job can align their own vehicle; consider it shade tree mechanics 201.