Originally Posted by AudiDudi
2016 Prism 24G with 14.5k miles. I'm seeing outside edge tire wear (have to replace the tire!) on the passenger side front. Driver's side is OK. I had the alignment checked about a year ago and it was in spec. Tire pressures are checked on a regular basis and pressure is good. It seems most of the wear happened in the last 1500 miles.
Any thoughts as to what to look for?
Outside edge wear can be caused by several things. Excessive Camber is one that comes to mind first and often. If it's on the passenger side it could also be caused by "Cornering".
Believe it or not, in this country where we drive on the RH side of the road and the steering wheel is mounted on the left, we tend to be more agressive when turning left. Our seat is right there in the corner and we can see everything real well so we aren't as timid as when cornering to the right. This is just one factor.
Second is road crown. It tends to push a vehicle to the right so it's necessary to steer slightly to the left. This puts the right steering tire in a constant yet slight left turn. This puts more load on the outside edge of the passenger tire.
Last item is suspension geometry. Independent suspension changes geometry with every bump. Camber changes as well as toe angle. Depending on the position of steering arm in relation to the inner pivot on the tie rod, every bump can cause the tire to toe in. Can also be influenced by a change in load in the vehicle. Any shift of load from when it was aligned can make big changes in this behavior depending on how much and which way it was shifted.
Depending on the severity of the wear one might just regularly exchange positions of the tire from left to right until both are worn and then see if replacement exhibits the same wear. Sometimes it's just the tire.
Have the alignment checked again and do so with the vehicle loaded exactly as you travel most of the time (Water tank full or partially empty, cargo stowed the same, bathtub filled with canned goods, or whatever).