LINKBXQ

Evening everyone.
I did search and been searching the forums and internet for a bit and didn't get a clear answer to my dilemma. My car is an AWD E550 4matic. I hit a pothole driving the great road of the BQE Christmas evening and got a nice bubble in both front tires. I have road hazard warranty on these tires and this is where my headache start. Currently I have the Yokohama Advan Sport A/S and they are great tires. They are much better than the continental procontact I had originally. I love these tires but the last time I try to get these replace under warranty it was such a hassle and they are giving me the run around again. I got these tires in August of 2017 and had one front right tire replace about 6 month later with exact same tire; after over a month of back and forth because they claim tire is discontinue which I found was a lie after contacting Yokohama. I drive less than 6000-7000 miles a year with this car and I have to push it to even get those miles.

I know a bit about the differential and AWD system after some reading, but here is my questions.

1. Does anyone know the exact different in thread wear for the awd system in our model car, I am seeing number anywhere from 2/32 to 5/32 here on the forum and elsewhere being thrown around as safe for the system.

2. Can I swap out two tires only, in this case the two front tires, with the same brand but different model. The model they told me they could get for me is the Yokohama Ascend GT which has a V speed rating instead of a Y speed rating. The Ascend GT A/S would be going on the front while the old Yokohama Advan Sport will be in the back. Again, from my search some say newer tire should go in the back while other say newer go in the front so any clarification there would be appreciated too.

3. Can I swap out the front with two tire of different brand altogether? Because of time constraint, the holidays, work and school, I need to replace these asap. They are telling me it might be until next week when they can get the Yokohama Ascend GT in, so in that case if I replace the two front with a completely different brand would that be an issue. The tire tech is pushing that and offer me Cooper but after reading review, I rather go for the General Altimax. I really don't like this option and would really avoid it. But if I have two tires in the front that is the same and two in the back that is the same, would that affect the AWD system?

4. The other option is just buying two Yokohama Advan Sport from Tire Rack. Two tires is about 370 where using my road hazard warranty I can get two for around 120 plus cost of installation.

I would like to make an inform choice to spend money wisely. I would love to hear other suggestion on this, especially if having same brand but difference model is ok to do.

Thank and happy new year!

http://www.mavistire.com/tire-brands...id=42210&frb=B
http://www.mavistire.com/tire-brands...id=78052&frb=B
http://www.mavistire.com/tire-brands...id=69623&frb=B

cetialpha5

No real suggestion here, tough not having the tire in stock. You're probably ok with that 2-5/32's worth of difference, I've done the same thing, but with my flats, they were more in the 2-3/32's range, haven't done something where it's 5/32's.

As for where the new tires go, it's always the back of the car. If you search tire rack, there's some article that says that. Basically when driving thinner tires on front, you'll notice the loss of traction and can control it better, once the rears go, you can go into a spin out and it's much harder to control so new tires are always on the back.

As for the different brands, well let's just say that I always try to keep the same tread pattern on all 4 tires.

KEY08

kajtek1

First, compare the tires rpms as even with the same nominal size, they might have big difference. Rule of thumb says 3% is allowable, but you will also have wear difference, so new tires rpms need to be recalculated.
The front v/s rear for new tires installation is ages old discussion. The only technical reason for putting them on the rear is better acceleration.
Years ago I was driving on snow/ice a lot and I did try good tires on the rear. The car was constantly loosing traction on braking and on sharp turns. With ESP that might even magnify.
Once I put good tires on front, the problems stop.
I rather have good braking/turning traction, than good acceleration.

cetialpha5

Here's the tire rack article. Doing the above can be dangerous and you risk a spin out in rain that you can't control.

https://www.tirerack.com/tires/tiret....jsp?techid=52

kajtek1

As I said, the myths are generations old.
When over/understeer can be different on different cars and is personal preferences, it is front tires that do 90+ % of panic braking.
When you can't stop, or turn the car having bad tires on front, the results can show pretty drastically.
Than controlling the understeer by modulating gas pedal like article suggest -is not for everybody.
Lastly the suggestion that hydroplaning is easy to control is total BS. Once you start hydroplaning at high speed - you have nothing, nada till water slows car down or moves to drier spot.

cetialpha5

It's not a myth. It's based on actual science.

If your tires are that bad in the front, you should get new tires. When you hydroplane, it's much easier to control when you can sense it in the front with the steering wheel and you'll notice that the tires aren't responding to steering inputs and you slow down. You won't notice that with new tires in the front and then the back will swing out on you when it's too late.

Anyway, risk your life anyway you like, people can choose to take any free advice they'd like. There's a reason most tire stores will only install a new pair of tires on the rear.

kajtek1

There is no science in it. Pure laws of psychics.
If you don't value good braking in your car- that is your choice for sure.
Why spend money on good brake pads when you don't have tires that can transfer the force to the ground?

cetialpha5

I think you have different priorities than most people. While it's true that having better tires on front will help with braking, I usually don't tailgate that bad and don't normally need maximum braking. Whereas I do encounter hydroplaning once in a while when you hit a wet stretch or if you're taking an off ramp in the rain. I'd rather not risk having the rear end going before the front end. That's a much more difficult driving situation than needing to brake.

Also thinner tires only matter if you're hydroplaning, whereas having less traction in the rear than the front can easily cause a spin. Braking performance is about the same with high/low tread depth, the coefficient of static friction should be about the same. Usually brake pads aren't the determining factor in stopping, that's really the tires which is why you have ABS, most modern cars can easily lock the brakes.

Basically you're giving out bad advice and you don't even know it.

kajtek1

All I can say is that you should try and gain your own experience.
Trolling here with paper knowledge is not helping anybody.