I need to replace all 4 tires on my 2006 Lexus GS300 AWD. I have heard that, with AWD, I should not buy new tires with unidirectional tread design, because the restriction on tire rotation (front-to-back only-no cross over) could lead to uneven wear that could affect AWD handling. Is this true, and can you please exlplain why?
Why do you need to replace with unidirectional?
I cannot think of any reason why it would cause a problem.
Does your owner’'s manual say anything about this? If not, I’d feel free to go with unidirectional tires.
I don’t need to replace with unidirectional, but my primary choices of replacement tires (Michelin Pilot Sport A/S Plus; Bridgestone Potenza) happened to have unidirectional treads.
This would be an issue, regardless of AWD. I wouldn’t worry about it.
I’m not sure how particular the Lexus system is about matching tire circumferences (unlike, say, the Subaru system that can easily be damaged). Regardless, my guess is that the front-to-back rotation will be sufficient to keep them pretty close.
"AWD and directional tires"
Not Practical. Silly, Really.
I have run nothing but unidirectional performance tires on my AWD cars with no longevity or other issues.
I have winter and summer tyres (4 each). One set is directional, one is not. I only rotate both sets front to back. I don’t see any problems.
Look in yuor owner’s manual. I venture to guess that the recommended tire rotation pattern is front <–> back only.