Directional tires and AWD

[CapriRacer]

Originally Posted By: BHopkins
What are these "additional complications" with directional or asymmetrical tires, that you speak of?.....


I'm going to start at a different spot, but I will be running over the same territory as others.

Many years ago, the company i used to work for conducted a test of a directional tire - running it forward and backwards. The wet traction only changed by 10% - which means there was only a 5% difference between a directional and a non-directional tire. That's not enough for the average motorist to notice - plus it is smaller than the differences between tires (meaning make and model).

Asymmetrical tires dependent on difference in camber to gain an advantage - and by "camber" I mean relative to the road, not relative to the car. Softly sprung cars would amplify this, but the usual usage for asymmetrical tires is - ironically - performance cars.

So I don't think there are significant differences in performance for either directional or asymmetrical tires. I also think this is done more for marketing and "saleability" than anything else.

That said, the initial problem with these types of tires is getting them mounted correctly. I've made the mistake myself, so I can understand why an overworked tire buster might make the mistake also.

That means that the initial mounting needs to be checked after purchase.

Then rotating tires also needs to be checked.

And every time a tire is repaired.

And when changing from winter tires.

And did we talk about staggered fitments?

That seems to me to be a lot of hassle for such a small amount of performance.

Now, I'm not saying people shouldn't buy directional or asymmetrical tires. I'm saying that I wouldn't specifically go after them just because there appears to be some performance advantage.

 

[BHopkins]

Originally Posted By: CapriRacer
Originally Posted By: BHopkins
What are these "additional complications" with directional or asymmetrical tires, that you speak of?.....


I'm going to start at a different spot, but I will be running over the same territory as others.

Many years ago, the company i used to work for conducted a test of a directional tire - running it forward and backwards. The wet traction only changed by 10% - which means there was only a 5% difference between a directional and a non-directional tire. That's not enough for the average motorist to notice - plus it is smaller than the differences between tires (meaning make and model).

Asymmetrical tires dependent on difference in camber to gain an advantage - and by "camber" I mean relative to the road, not relative to the car. Softly sprung cars would amplify this, but the usual usage for asymmetrical tires is - ironically - performance cars.

So I don't think there are significant differences in performance for either directional or asymmetrical tires. I also think this is done more for marketing and "saleability" than anything else.

That said, the initial problem with these types of tires is getting them mounted correctly. I've made the mistake myself, so I can understand why an overworked tire buster might make the mistake also.

That means that the initial mounting needs to be checked after purchase.

Then rotating tires also needs to be checked.

And every time a tire is repaired.

And when changing from winter tires.

And did we talk about staggered fitments?

That seems to me to be a lot of hassle for such a small amount of performance.

Now, I'm not saying people shouldn't buy directional or asymmetrical tires. I'm saying that I wouldn't specifically go after them just because there appears to be some performance advantage.


CapriRacer,

Thanks for taking the time to explain. That all makes sense.

To me, it seems that a lot of the concerns you mention are also relevant to non-directional tires. With tires that have a whitewall on one side, I have always had to check after initial install, to make sure that the correct wall is mounted outboard. And, I have always had a discussion with the tire shop to assure that a proper 4 wheel rotation is done. I have friends that will even mark the tires before going in, to assure that the rotation is done correctly.

It seems to me that if you are one of those that are obsessive about tires, then these are all just simple details to watch, whether the tires are directional, asymmetrical, or standard. And a person that is obsessive about tires is going to have a hard time avoiding directional or asymmetrical tires. After all, he or she is more likely to be into performance tires, or have a set of winter tires, both of which are likely to be directional.

If one is not obsessive about tires, well, they probably aren't here on the bobistheoilguy.com tire and wheel forum.

That's my

.

 

[thr_wedge]

on my subaru it was just front to rear.

didn't matter since the tires would barely last 20k...