Tire wear vs speed
- Thread starter supton
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Nope. On the Jetta, I did do rear brake pads at 168kmiles. At 175kmiles I had to do the fronts, as one pad rusted off--the other there had half the pad material left. Just checked over the holiday, and all 8 pads have half their material left after 100kmiles. So I don't think it's aggressive braking.
Camry, hard to say. One pad is down to 3mm after 50kmiles, the other 7 are still at 10mm. [Rusted on the caliper, fixed that issue.]
Both are stickshift, and while we don't downshift through all the gears we often coast to stops.
I'm guessing it's cornering and road surface. Perhaps high(er) highway speeds too.
Camry, hard to say. One pad is down to 3mm after 50kmiles, the other 7 are still at 10mm. [Rusted on the caliper, fixed that issue.]
Both are stickshift, and while we don't downshift through all the gears we often coast to stops.
I'm guessing it's cornering and road surface. Perhaps high(er) highway speeds too.
Originally Posted By: Hokiefyd
Originally Posted By: CapriRacer
Put another way, straight ahead driving is practically free.
This has to assume a very neutral alignment, right? An alignment set up for good handling/response may have a moderate amount of toe, and in this case, the tire will always be in a scrub as it rolls down the road...even a straight road, right?
Some say that toe in is used to keep the front wheels parallel when they are moving as they tend to splay out otherwise. It's all a question fo degree, a good alignment shop often has a "senior" employee who has a feel for proper settings far beyond numbers on a machine.
Originally Posted By: CapriRacer
Put another way, straight ahead driving is practically free.
This has to assume a very neutral alignment, right? An alignment set up for good handling/response may have a moderate amount of toe, and in this case, the tire will always be in a scrub as it rolls down the road...even a straight road, right?
Some say that toe in is used to keep the front wheels parallel when they are moving as they tend to splay out otherwise. It's all a question fo degree, a good alignment shop often has a "senior" employee who has a feel for proper settings far beyond numbers on a machine.
Originally Posted By: Hokiefyd
Originally Posted By: CapriRacer
Put another way, straight ahead driving is practically free.
This has to assume a very neutral alignment, right? An alignment set up for good handling/response may have a moderate amount of toe, and in this case, the tire will always be in a scrub as it rolls down the road...even a straight road, right?
My experience is that toe doesn't add to handling - only detracts. Camber on the hand can add to handling, but it is extremely sensitive to the toe setting - toe acting as a multiplier relative to tire wear.
And here's where it gets tricky and problematic.
Many race cars that are converted street machines will use the toe setting to compensate for the Ackerman - the difference in toe angles when the steering wheel is turned. If you are cornering a car hard, you need less Ackerman than if you aren't. Street cars are set up for light levels of cornering and cars converted for racing purposes benefit from fixing the Ackerman. And if you can't fix the Ackerman, setting the toe to "toe out" is one way to get the proper toe when cornering.
But you are right. Driving a car straight ahead with a bunch of toe-in in the front tires just wears them out quicker.
Originally Posted By: CapriRacer
Put another way, straight ahead driving is practically free.
This has to assume a very neutral alignment, right? An alignment set up for good handling/response may have a moderate amount of toe, and in this case, the tire will always be in a scrub as it rolls down the road...even a straight road, right?
My experience is that toe doesn't add to handling - only detracts. Camber on the hand can add to handling, but it is extremely sensitive to the toe setting - toe acting as a multiplier relative to tire wear.
And here's where it gets tricky and problematic.
Many race cars that are converted street machines will use the toe setting to compensate for the Ackerman - the difference in toe angles when the steering wheel is turned. If you are cornering a car hard, you need less Ackerman than if you aren't. Street cars are set up for light levels of cornering and cars converted for racing purposes benefit from fixing the Ackerman. And if you can't fix the Ackerman, setting the toe to "toe out" is one way to get the proper toe when cornering.
But you are right. Driving a car straight ahead with a bunch of toe-in in the front tires just wears them out quicker.
Quote:
There's a tradeoff between "self centering" feel and tracking and tire wear.
Huh? Caster, the inclination of the steering axis, is what I think of for self-centering. How does that cause tire wear? While many cars these days do not have a caster adjustment, on my Tundra with full adjustability, I always have the alignment tech set the caster at the max allowable, the steering feels great, and tire wear is excellent. (I have them set the camber and toe-in at the center of the spec. NOT just anywhere within the spec. It can take some determination by the customer to get them to set the alignment at specific points--and with nothing outside the spec the tech has nothing to complain about.)
Supton, two things you haven't mentioned--pavement temperature when you're driving long trips, and the kind of gravel used in the pavement. Some regions get gravel from local quarries where the aggregate has sharp edges that wear tires.
There's a tradeoff between "self centering" feel and tracking and tire wear.
Huh? Caster, the inclination of the steering axis, is what I think of for self-centering. How does that cause tire wear? While many cars these days do not have a caster adjustment, on my Tundra with full adjustability, I always have the alignment tech set the caster at the max allowable, the steering feels great, and tire wear is excellent. (I have them set the camber and toe-in at the center of the spec. NOT just anywhere within the spec. It can take some determination by the customer to get them to set the alignment at specific points--and with nothing outside the spec the tech has nothing to complain about.)
Supton, two things you haven't mentioned--pavement temperature when you're driving long trips, and the kind of gravel used in the pavement. Some regions get gravel from local quarries where the aggregate has sharp edges that wear tires.
Different strokes. Go to Discount Tire and get the tires with the longest tread warranty(80,000). Cost $600.Wear them out at 40,000 and you get a $300 credit toward the next set of tires. Now you get fresh rubber for ALL of you miles. P.S. Have the car 4 wheel aligned every time you get new tires.
Originally Posted By: supton
Pavement temps are usually cool, most of our long trips are biased towards the evenings. Most of my driving is done during rush hour. NH usually isn't that warm either.
THIS is more relevant I should think...heat rather than speed. Same speeds in Florida heat (on shell embedded roadways) would likely result in more wear than up north...
Pavement temps are usually cool, most of our long trips are biased towards the evenings. Most of my driving is done during rush hour. NH usually isn't that warm either.
THIS is more relevant I should think...heat rather than speed. Same speeds in Florida heat (on shell embedded roadways) would likely result in more wear than up north...
Very nice comments on a range of topics but not much discussion of the actual question posed. Does increased speed equate to increased tire wear? (not talking about cornering, just straight ahead driving) Seems like a good question that I've never really considered. Couple thoughts - increased speed leads to higher tire temps. Higher tire temps would soften the rubber. Softer rubber may wear faster. On the other hand faster speeds increase tire pressure which typically increases tread life. Another thought, even though we are talking about straight ahead driving, there are slight steering corrections constantly being made to track straight so in effect you are cornering, just minute amounts. I'd still like to hear an answer to the question from an engineer.
Quote:
Have the car 4 wheel aligned every time you get new tires.
Why relate alignment to new tires? Get the wheels aligned when you feel the need through the wheel or when the tires show uneven wear as caused by malalignment. If you're due for new tires and the old tires wore evenly and the steering wheel doesn't pull, why spend the money for an alignment?
Yes, agreed, 4 wheel alignment on cars with 4 wheel adjustments, and thrust alignment on the others where the direction of thrust of the rears is measured, and the fronts aligned to that. And, insist that the alignment tech hit the center of the aligment spec range, not just anywhere within the range.
I know, not speed and tire wear related.....
Have the car 4 wheel aligned every time you get new tires.
Why relate alignment to new tires? Get the wheels aligned when you feel the need through the wheel or when the tires show uneven wear as caused by malalignment. If you're due for new tires and the old tires wore evenly and the steering wheel doesn't pull, why spend the money for an alignment?
Yes, agreed, 4 wheel alignment on cars with 4 wheel adjustments, and thrust alignment on the others where the direction of thrust of the rears is measured, and the fronts aligned to that. And, insist that the alignment tech hit the center of the aligment spec range, not just anywhere within the range.
I know, not speed and tire wear related.....
Originally Posted By: CapriRacer
To my mind, the largest contributor to tire wear is corners. Why? Because in order to move the mass of the car, a tire has to generate a slip angle - and it's that slip angle that causes most of the wear.
If I take corners on two wheels, will I cut my tire wear in half?
LOL, J/K
To my mind, the largest contributor to tire wear is corners. Why? Because in order to move the mass of the car, a tire has to generate a slip angle - and it's that slip angle that causes most of the wear.
If I take corners on two wheels, will I cut my tire wear in half?
LOL, J/K
Originally Posted By: 05lgt
Very nice comments on a range of topics but not much discussion of the actual question posed. Does increased speed equate to increased tire wear? (not talking about cornering, just straight ahead driving) Seems like a good question that I've never really considered. Couple thoughts - increased speed leads to higher tire temps. Higher tire temps would soften the rubber. Softer rubber may wear faster. On the other hand faster speeds increase tire pressure which typically increases tread life. Another thought, even though we are talking about straight ahead driving, there are slight steering corrections constantly being made to track straight so in effect you are cornering, just minute amounts. I'd still like to hear an answer to the question from an engineer.
2 thoughts:
Yes, higher speeds lead to faster wear rates. But the difference in wear rate due to speed is completely over shadowed by the difference cornering does.
Put a different way, the original question asked wasn't really what the OP wanted to know, so the answers he got addressed his needs, but not his question.
Very nice comments on a range of topics but not much discussion of the actual question posed. Does increased speed equate to increased tire wear? (not talking about cornering, just straight ahead driving) Seems like a good question that I've never really considered. Couple thoughts - increased speed leads to higher tire temps. Higher tire temps would soften the rubber. Softer rubber may wear faster. On the other hand faster speeds increase tire pressure which typically increases tread life. Another thought, even though we are talking about straight ahead driving, there are slight steering corrections constantly being made to track straight so in effect you are cornering, just minute amounts. I'd still like to hear an answer to the question from an engineer.
2 thoughts:
Yes, higher speeds lead to faster wear rates. But the difference in wear rate due to speed is completely over shadowed by the difference cornering does.
Put a different way, the original question asked wasn't really what the OP wanted to know, so the answers he got addressed his needs, but not his question.
Originally Posted By: Carbuff
Originally Posted By: CapriRacer
To my mind, the largest contributor to tire wear is corners. Why? Because in order to move the mass of the car, a tire has to generate a slip angle - and it's that slip angle that causes most of the wear.
If I take corners on two wheels, will I cut my tire wear in half?
LOL, J/K
Ha-Ha! No overall, but two of your tires will receive less wear!
Originally Posted By: CapriRacer
To my mind, the largest contributor to tire wear is corners. Why? Because in order to move the mass of the car, a tire has to generate a slip angle - and it's that slip angle that causes most of the wear.
If I take corners on two wheels, will I cut my tire wear in half?
LOL, J/K
Ha-Ha! No overall, but two of your tires will receive less wear!
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