Is it still true that you have to take it easy the first 50 miles on new tires. (I know not to do burnouts) I'm talking about some speed or below required or something.
"Rule" about fist 50 miles New Tires
- Thread starter SumpChump
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Drive them normally. Millions of other folks do without issue.
I think that is due to the release agents used to get the tire out of the mold.
JHZR2
Staff member
Ive always heard that, potentially it is as much to let QC/QA shake out before jumping on it, as anything. You know, mechanic error and infant mortality.
Ive always taken it easy on new tires, but I generally are pretty easy anyway on my cars, other than in controlled situations.
Ive always taken it easy on new tires, but I generally are pretty easy anyway on my cars, other than in controlled situations.
I was asking since I may have 10 miles around town driving before heading out on the highway for the hour drive home from installer.
JHZR2
Staff member
I wouldn't worry much. I'd be considerate of blasting on the highway, taking on ramps too fast, going way over the speed limit, etc.
Because the possibility of some release agents effecting traction performance, I suspect that the main thing is to drive as if it were, say, snowy out, and be a little careful. Don't overthink it.
Because the possibility of some release agents effecting traction performance, I suspect that the main thing is to drive as if it were, say, snowy out, and be a little careful. Don't overthink it.
I bought tires back in my teens and they told me to stay under 50mph for at least 100 miles. First and only time I've ever heard that.
Errrm, normal highway driving is "taking it easy".
You want to get a few thermal cycles on them before running them hard e.g a HPDE course. Otherwise they tend to get greasy and shed rubber.
You want to get a few thermal cycles on them before running them hard e.g a HPDE course. Otherwise they tend to get greasy and shed rubber.
It's more for your own safety not for the tire, as you won't have good traction until you break in the tire, so you can easily outdrive yourself into an accident. This is both the release agents, as well as the nubs and contact patch wearing to the alignment of your car. Most tire manufacturers will say 500miles not just 50. Tirerack will have articles
Additionally, just like car racing, if you flatspot your tires, then you've just stuck yourself with a less-than-round tire for the rest of it's lifespan.
However for the very first day and when you do get your car back from the tire shop, you do need to go easy as there is potentially still wet tire lube. Hard driving right back from the shop has been known to slip the tire on the rim and thus throw off the balance.
Additionally, just like car racing, if you flatspot your tires, then you've just stuck yourself with a less-than-round tire for the rest of it's lifespan.
However for the very first day and when you do get your car back from the tire shop, you do need to go easy as there is potentially still wet tire lube. Hard driving right back from the shop has been known to slip the tire on the rim and thus throw off the balance.
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Never thought of the possibility of the tire slipping on the rim from tire lube.
You're way over thinking it...just drive.
I think its more applicable to motorcycles. On a bike new tires are noticeably slick for a short time.
So looking at this from a tire engineer's perspective:
There are 3 things that take place when a tire is first put into service:
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
2) There are compounds on the tire to aid in extracting the tire from the mold. Some are sprayed on the tire before it is placed in the mold and some a sprayed on the mold before the tire is place in it. In either case, the outside of the tire has these compounds on the surface (and slightly penetrated into the surface).
Some of these can be quite slippery, esp[ecially when wet, so caution is advised with new tires as it can take a couple hundred miles to wear them off.
3) The rubber contains waxes to help preserve the tire - both in storage and in service. Obviously, the tread gets constantly worn off, so the waxes don't stay on the tread surface. But during the first few miles, the flexing of the tire causes the waxes to move to the surface, where they flake off.
There are other things that also migrate when the tire is flexed - antioxidants, oils, un-reacted chemicals, etc - and they will get imbedded in the waxy build up. That's why you may see newish (as in a few days or weeks) tires with a color other than black. It's those other things migrating to the surface and being captured by the waxes - which eventually flake off. We aren't talking about a lot of stuff, but you can see it and it can make the tread surface a bit slippery.
Slippage on the rim? Not so much. First, it takes quite a bit of movement for balance to be affected. Second, slippage is usually small even if there is slippage. The only time I have heard of issues is when silicone is used - and then the problem is HUGE!!
There are 3 things that take place when a tire is first put into service:
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
2) There are compounds on the tire to aid in extracting the tire from the mold. Some are sprayed on the tire before it is placed in the mold and some a sprayed on the mold before the tire is place in it. In either case, the outside of the tire has these compounds on the surface (and slightly penetrated into the surface).
Some of these can be quite slippery, esp[ecially when wet, so caution is advised with new tires as it can take a couple hundred miles to wear them off.
3) The rubber contains waxes to help preserve the tire - both in storage and in service. Obviously, the tread gets constantly worn off, so the waxes don't stay on the tread surface. But during the first few miles, the flexing of the tire causes the waxes to move to the surface, where they flake off.
There are other things that also migrate when the tire is flexed - antioxidants, oils, un-reacted chemicals, etc - and they will get imbedded in the waxy build up. That's why you may see newish (as in a few days or weeks) tires with a color other than black. It's those other things migrating to the surface and being captured by the waxes - which eventually flake off. We aren't talking about a lot of stuff, but you can see it and it can make the tread surface a bit slippery.
Slippage on the rim? Not so much. First, it takes quite a bit of movement for balance to be affected. Second, slippage is usually small even if there is slippage. The only time I have heard of issues is when silicone is used - and then the problem is HUGE!!
It is very possible to spin a freshly mounted tire on a wheel if driven hard. I had it happen when I autocrossed my car the day after the tires were mounted. Felt the car shudder under max braking, and the car shook after that. Had to re-balance. The same release agents on the tire are also on the bead, and until the tire lube has a chance to dry for a couple of days it would be very easy to slip a big tire with a high powered vehicle, or anything under very hard braking. Not all tires fit super tight on the wheel either. Some beads will seat at less than 10 psi, and others might be 50 or higher. If I mount big sticky tires on a car with 400 plus horsepower, Brembo brakes, etc., I will put a dot by the valve stem to monitor it. Just drive normally for a few days before you start beating on your tires. And if the tires are mounted correctly, especially with very low profiles, you use a lot of tire lube on the wheel and tire, and it does not dry instantly.
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Just for kicks, after mounting up a fresh set of tires on my Chevy Silverado 5.3 a few years ago, I did an awesome burnout from the Sams Club parking lot onto the I-10 service road. LOL
I probably burnt up about 5000 miles of normal tread wear, but whatever, LOL!
I probably burnt up about 5000 miles of normal tread wear, but whatever, LOL!
Originally Posted By: CapriRacer
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
This one is weird and creepy. If I over-inflate a new tire, will it grow too much?
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
This one is weird and creepy. If I over-inflate a new tire, will it grow too much?
Originally Posted By: SumpChump
Is it still true that you have to take it easy the first 50 miles on new tires. (I know not to do burnouts) I'm talking about some speed or below required or something.
Don't lean on the tire at 102 % in those first 100 miles of corners and max braking, because it may only have 80 or 90% of its traction...! Realistically, drive the tire a bit easier for the first week , and you'll be just fine... it' s not like the tire has 10 % of its grip until broken in... more like 10 % less... maybe...!
Is it still true that you have to take it easy the first 50 miles on new tires. (I know not to do burnouts) I'm talking about some speed or below required or something.
Don't lean on the tire at 102 % in those first 100 miles of corners and max braking, because it may only have 80 or 90% of its traction...! Realistically, drive the tire a bit easier for the first week , and you'll be just fine... it' s not like the tire has 10 % of its grip until broken in... more like 10 % less... maybe...!
I never really heard of this before or thought about it much, but it does remind me of when I had some Destination A/Ts put on my truck a few years ago.
I had just had them put on and was driving around just to see how they drove. I got stuck behind a nervous/scared driver who was hesitating to make a left turn, so I turned the wheel and hit the gas to get over in another lane from a stop. It was not my intent to take off aggressively, but when I hit the gas the truck just started smoking one of the rear tires (open diff). Caught me off guard and I breifly felt like a douche even though the screaming peel out was not the goal in mind, but I know how it probably came across.
I had just had them put on and was driving around just to see how they drove. I got stuck behind a nervous/scared driver who was hesitating to make a left turn, so I turned the wheel and hit the gas to get over in another lane from a stop. It was not my intent to take off aggressively, but when I hit the gas the truck just started smoking one of the rear tires (open diff). Caught me off guard and I breifly felt like a douche even though the screaming peel out was not the goal in mind, but I know how it probably came across.
Originally Posted By: friendly_jacek
Originally Posted By: CapriRacer
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
This one is weird and creepy. If I over-inflate a new tire, will it grow too much?
First, the growth is only a bit. To give you an idea, it is common in our shop to add 2 or 3 psi to newly mounted tires so that later (after growth) it will be right. If you use the Ideal Gas Law, that's about 2% or 3% volume growth.
And to help people get their heads around this, If I increase the diameter of a sphere 2%, the volume increases about 6%. So we are talking about a 1% diameter growth - or so.
Increasing inflation pressure does indeed cause more growth, but it isn't all that different than what you would get with regular pressure. However, you can measure the difference in diameter between the 2 pressures, but the growth isn't that much different.
Originally Posted By: CapriRacer
1) It grows. The inflation pressure causes tension in the tire and the materials react by stretching. It takes 24 hours to get most of it out. In fact, when tire manufacturers measure the diameter, width, etc. of tires, they commonly refer to those measurements as "24 hour measurements" - because those measurements take place 24 hours after the tire is mounted. A tire will continue to grow long after 24 hours, but 24 hours gets most of the growth out and is a convenient point in time to record the measurements.
This one is weird and creepy. If I over-inflate a new tire, will it grow too much?
First, the growth is only a bit. To give you an idea, it is common in our shop to add 2 or 3 psi to newly mounted tires so that later (after growth) it will be right. If you use the Ideal Gas Law, that's about 2% or 3% volume growth.
And to help people get their heads around this, If I increase the diameter of a sphere 2%, the volume increases about 6%. So we are talking about a 1% diameter growth - or so.
Increasing inflation pressure does indeed cause more growth, but it isn't all that different than what you would get with regular pressure. However, you can measure the difference in diameter between the 2 pressures, but the growth isn't that much different.
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