When To Replace Tires?
The question of when to replace tires seems a rather simple one, but actually to make an informed and balanced decision there are a few factors to consider.
The Qualitative Factors
For most tires, following the break in period there is a slow but steady decline in performance and comfort. The qualitative decline creeps up on you like that extra 10 lbs., and then one morning you wake up and realize your tires aren’t delivering the performance they once did, and that pair of pants didn’t always fit so tightly… you get the point.
So with many tires, and often times thousands of miles before they’ve officially reached minimum tread, the quality has fallen off drastically.
This can mean a loss of performance in all road conditions – dry conditions, wet conditions, wintry conditions. Accordingly, it can also mean a decline in traction, maneuverability, braking, and overall safety. Indeed, worn but still officially viable tires have been proven to deliver notably less wet road braking performance (in particular) than those with substantial treadlife.
The qualitative decline is often accompanied by diminished comfort characteristics. Worn (but not officially “dead”) tires often exhibit increased road noise and a loss of ride quality relative to their new, post-break in condition. In fact, the poor comfort attributes are what users often notice more than anything else.
So when considering the replacement of tires, the condition and performance of the worn tires is a factor for many. And if you’re sensing a decline in performance and comfort, it’s probably not your imagination.
Nevertheless, for most folks the loss of optimum performance and comfort is not reason enough to replace tires.
The Minimum Treadwear, Economics-Based Approach
Even if you’re willing to cope with diminished performance and comfort, there will come a time when tire replacement is necessary from a treadlife perspective.
The tire wear bars as pictured below officially signal the decommission point of the tire. When the wear bars are equal to the surrounding tread, then you’ve reached 2/32” of tread. Definitely time to replace the tires.
But long before you reach the wear bars, you need to conduct your own informal tread depth test, which involves a grand total of $0.26 – one penny and one quarter. Utilize these coins to ascertain with some accuracy your remaining treadlife as explained here: Here’s How To Measure Tire Tread Depth With a Penny.
Some will tell you that running a tire down to 2/32” can be safely done. Others suggest that in order to deliver sufficient wet road performance 4/32” of treadlife is required, and with any less tread the tires should be replaced if wet roads will be encountered.
The truth of the matter is that there is no objective rule because tire performance, especially adverse condition tire performance, varies significantly from tire to tire. For example, through a rain storm we’d take our chances with a near-minimum tread, excellent wet weather tire like the Continental ExtremeContact DW over numerous tire alternatives with more tread. And some modern tires like the Michelin Premier LTX are specifically designed and engineered to maintain wet weather performance as tread wears.
Our advice: listen to, and heed the signals from behind the wheel first and foremost, and use the wear bars and tread measurements as reference points. Just because you have >2/32” of tread remaining doesn’t mean that your tires are delivering adequate performance. Particularly in wet or poor road conditions. Whatever you do, don’t establish >2/32” tread depth and then dismiss the concern despite your sense that performance and safety are diminished.
And so the decision of when to replace tires comes down to your tires, their overall competence, your vehicle, and your intuition. Just don’t push it… the delayed expense of replacement tires isn’t worth risking your safety.