At what tread depth are you getting new summer tires?

[fooitm35x]

I have Continental ExtremeContact DW on my summer set and they are now at 5/32.
When should I get the new tires (I have winter tires and going to swap soon - my question is about the summer tires)?
Thanks in advance!

[BlackCat81]

Summer only? I'd replace them at 3 32nds.

[fooitm35x]

Thank you!

[szh]

Technically, the legal limit is 2/32", but if you are driving in any rainy weather, then I would replace them sooner!

Somewhere between 3/32" and 4/32" is the right place to do so (I start looking for tire deals at around the 5/32" to 4/32" mark) - below that, the increased braking distances are downright dangerous.

A long time back, I posted a link to a video that showed some testing done by Tire Rack ... will look to see if I can find that and link it in here.

Z

[szh]

Pardon the pedantic repost (last time was 2007 though ), but here my guidelines for tires for our cars:

My guidelines for tires, in no particular order, are as follows - some of these guidelines are specific for the M (with its heavier weight), of course:

1. Change the tires when you get to about 4/32" of tread depth. Yes, you can legally get to 2/32", but it had better not be raining in your neck of the woods when you are out there! Look at the video I have posted for the difference in wet weather braking with 2/32 and 4/32 tread depth ...

2. Buy a tread depth gauge (less than a few bucks at most auto parts, Sears, Walmart and Target stores). This is far more useful than the "quarter" (for 4/32") or "penny" (for 2/32") tricks. Heck, buy a few and put one in the glove compartments of all your cars!

2. For the M, make sure that the tire load index is at least 95 (preferably much higher), no matter what the actual diameter of tire/wheel. Anything less, and you are going to have internal tire damage (assuming no actual tire blowout) that will require frequent re-balancing, and lead to premature tire failure.

3. Set the tire inflation pressure to 36psi or higher. This gives you the actual load index performance measurement point. To compromise a bit on comfort, if you want to run at about 32 to 33 psi, get a load index tire of 100.

4. Never install or use tires past the 5 year mark from the date of manufacture (on the sidewall ... next to the "DOT" symbol). You could stretch this to 6 years, but I think you are asking for trouble. Change the tire, no matter what the mileage or tread depth if the tire is more than 5 years old from the date of manufacture (not the date of "first in service").

5. Make sure that you use summer tires for summer and change to snow tires for any snow conditions, or temperatures less than 34-35 degrees Fahrenheit.

6. Make sure that the speed rating is at least H (preferably higher, like V, W, Y or Z). Never think that the M can handle T or S rated tires - the internal construction strength of these tires is not good enough for the weight of this car.

7. Never exceed the speed for the rating for your tire. For H tires, this is 130mph.

8. Once the tire has been patched for any reason whatsoever (like a tire puncture), never exceed 100mph - for any rating tire. Period!

9. Never speed on unbalanced or underpressure tires.

10. Follow the minimum and maximum tire width specs for the wheels you have, although being off 0.5" on the allowed range of wheel width is probably not a serious concern (albeit, remember that the actual tire footprint is changed ... "wider" tires may actually have a smaller contact width). VIP guys like to "stretch" tires (usually too little a width) ... personally, I consider the look completely silly (but that is my opinion) and, regardless, it is unsafe at speed or while cornering.

11. Check and adjust your tire pressure often - every week preferably, but a minimum of two weeks apart. With an accurate gauge - analog or digital. Tire must be cold. So, do it early in the morning, in your garage, before the sun has had a chance to warm it up even a bit.

12. Lower aspect ratio tires need more frequent pressure checks ... less air in there, and thus, more of a pressure change from week to week.

13. The UTQG tread life measure number is not comparable between manufacturers - only within the same manufacturer. It is a guideline, not an exact spec.

14. For high performance cars, I would never consider getting a tire with less than "A A", with a preference for "AA A". Gives me better wet braking and handling characteristics.

15. For powerful cars, don't assume that you can drive "All Season" tires in snow - and, of course, summer tires in snow would be an accident looking for a place to happen! Buy a cheap set of wheels and snow tires - even the cheapest snow tires will be safer than running summer tires in snow!

16. My opinion: if you can afford it, spend your money on good to excellent tires - even if you have stock 18" or 19" wheels - do not waste it on larger diameter wheels and tires (unless you have money to burn). Many of those larger diameter tires do not have the right load index anyway!

Z