Just took our 2005 Subaru Outback in for an oil change, and got the guys to rotate our tires, which they forgot to do last time (so it had been about 7500-10000 miles since last rotation, as we get oil changes every 4-5000 miles). The tires immediately begin making a lot of noise at speeds above 40mph, and instead of going way, it has only gotten louder and has even begun appearing at 30mph+. We've put about 1000 miles on the car with the noise, maybe over the last month. Handling is fine, alignment seems fine (steering wheel doesn't pull at all to the left or right) - everyhting seems fine except for the noise.
So we have Hankook Optimo H727s, which have about 50-60,000 miles and are probably 3.5-4.5 years old (they came with the care when we bought it in 2011, and they were 90% new). These tires are unidectional, so they can be cross rotated (X rotated?), but we don't know whow they rotated them - the shop hasn't gotten back to us yet.
The treads face different directions now on the left and right side of the cars. I am not sure if they did before. FR and RR face one way, FL and RL face the opposite way. Could this be the cause of the noise? If it was just uneven wear, I would expect it to decrease over time as the effect of the rotation begun to take effect.
For reference here is a pic:
One side has the left side of the tread facing outward, and the other side has the right side of the tread facing outward. Is this normal? Does it matter? I understand that unidirectional means that any tire could be on which ever way, but does unidirectional mean that the tires don't have all have to be facing the same way?
I do not believe the tire is asymmetrical because you can't draw a line through it vertically and fold the one half into the other. You can do this horizontally, but not vertically. See one of the four pics below.
The tires are no position like so:
Is that correct?
Or should they be differnt?