I have seen many post regarding tries wear and negative camper for IS models. I need some advice regarding replacing my front tires. I still have the stock Turanza el400 after 25k miles. I had ordered two tires (Michelin - Pilot Sport A/S 3+) at Costco, while trying to get it installed as per the Costco manger, I can't change the tires to Michelin - Pilot Sport A/S 3+ and I have to use the same brand Turanza el400 or else it will mess up my transfer case.

I am aware that for AWD, all the four tires should have the same level of tire tread. But for IS350, front and back have different tire sizes. So changing my front tires with any brand would it affect my transfer case in any way? My rear tires still have a good amount of thread on it and I intent to keep them for a while longer.

I would like to know how often other IS owner change their tires and does everyone change all the 4 tires at the same time.

Thank you
RD

 

I don't see why using a different brand would be an issue as long as the tires are exactly the same size. I agree with PatrixUSA, you should clarify the manager's concerns. There should be no issue with the transfer case based on the tire brand from what I know.

Also, I find it odd about the tread depth. I had one of my front tires - the passenger-side one - replaced at the dealership no problem. This was at about 12k miles or so. I asked if there would be any issues with the different wear levels, and the service advisor said no.

 

Believe it or not, tires of the same size specs, but different brands can actually be a different diameter. Take a look at the actual numbers on the manufacturer's website and you'll find that to be true. Although some brands are closer, there are some that are not within the recommended 3% difference. So as a policy, rather than compare brands, they just cover their butt and not recommended at all.

differences in tread depth, and slight variations from one manufacturer to the next can cause some issues. Although know you will be doing so at your own risk.

What I'd do in your case is just replace all 4, but keep the 2 good ones as spares just in case. Can be used in a pinch

 

Listen to your Costco manager, he is right, Hunter Engineer master Tech Alignment also told me that, he came to our shop to train theses guys, i was lucky to be there part of them and learn a lot from that Hunter Engineer, as you know most of Pro alignment or tire shops mostly give you this advice but it is up to you to believe, your car right ? yes different tire tread will mess up AWD system, the OEM stagger setup was designed to consistent to the car's suspension geometry and it was not design to use mix and match tread/tires.

Let say, 225/40/18 front - 255/35/18 rear will consistent to 225/45/17 and 225/40/18 all around, diameter and size will only effect Car's speed braking and ODO reader , Traction and tread will effect Gearing system , if you call "Hunter Engineer" and ask they will answer you more clearly, i'm just giving you advice whatever i learnt from Suspension Engineer, for example you don't ask the Engine Mechanic guy about Tire n Suspension, and you don't ask Electrical Mechanic about Engine. Its a big different between RICER and Pro Tuner i'm impress COSTCO know better than Canadian/American Tire.

 

This, it is likely due to their policy.
I'm not sure about the AWD but my RWD came with ER33 which are summer tires. EL400 are all season.

I would just change out all 4 tires, you only have about few thousand miles left on your rear tires anyway. And they suck.

 

Turanzas are the worst tire ever. I would change all 4 and the Michelin's are really good.

 

Costco has issue with a Mercedes and Subaru where they replaced the only two tire and it messed up their transfer cases. Costco ended up paying for transfer cases. At the end I was like, will put the tires on if I insist u too.. and he is like no.

For a AWD suv which has all the same for tires should replace all the 4 at the same time. But in my case Front and back are different tires and Front tires wearing out it a common this.

 

Dealership recommended to replace the front two tires at 20k service, but I wanted to max out the tires, so I kept it, I never asked what tire they were gonna use.

 

I do agree with what you say, but I not trying to change to a tire with different tire spec. Current I have Turanza 225/40R18, I am trying to put on a 225/40R18 Michelin.

 

Just bring in the wheels and have them switch out the rubber on them. The policy (which a lot of tire shops have) is against putting mismatched/underrated/etc tires on the vehicle itself, they have nothing against mounting and balancing.