Tires Q&A: Can I replace one or two tires at a time on my car?

Consumers Union held their annual open-house tour on Saturday, October 17 at the company headquarters in Yonkers, New York. Visitors got a chance to tour various stations to hear how Consumer Reports tests different products. It’s always a nice opportunity to talk about how we test tires at this event and as in past years there were a lot of interested visitors looking for more information on tires, particularly on how to buy.

Question: By far, the most common question asked this year was: “Is it OK to purchase just two tires at time?”

Answer: A simple question, indeed, and the simple answer is yes you can in most cases--but there are many considerations.

Most importantly, CR recommends rotating tires routinely following the guidelines spelled out in your vehicle’s owner’s manual, typically every 6,000 to 8,000 miles. The owner’s manual will have a rotation pattern to follow as well. Following the routine rotations will optimize a tire’s tread life and will wear all four tires evenly. Bottom line: when it comes time to replacing the worn-out tires, buy four new ones.

Many drivers may not rotate tires at all or not on a routine schedule. Owners of front-wheel drive vehicles will likely be replacing the front tires two to three times more often than the rear tires --since the front tires are doing most of the work by driving the wheels, doing most of the braking, and steering the car. The rear tires have a much easier life, being generally lightly loaded and free-rolling. In this common scenario, where only two tires are worn out and need replacing, CR recommends at least purchasing new tires of like brand and model as those already on the car, despite the best practice of purchasing a full set of four new tires. Mixing tire brands or even different models may cause handling instability. And when replacing only two, we recommend installing the new tires in the rear and placing the (older but still decent) rear tires in the front. This may help prevent a spinout or oversteer condition on slick roads. Both these recommendations apply to rear-wheel drive vehicles as well.

Finally, if you own an all-wheel drive vehicle, the first step before buying a new tire or pair of tires (short of installing four new ones) is to read the vehicle’s owner’s manual. Many makes of all-wheel drive vehicles will stipulate that all four tires must be of the same size, brand, model, and state of wear. Any deviation could result in an all-wheel drive system failure due to the stress placed on it from rotating dissimilar overall diameter tires.

Now wasn’t that simple?

To see full details on all tire models we tested, check out our Ratings and recommendations (available to subscribers). In addition to our updated Ratings, all site visitors can access our free buying advice for tips on getting started, types of tires we test, features that are important in making a tire purchase, and general tire care. Also, be sure to check out our TireTalk forum to interact with our tire engineers and other drivers.

—Gene Petersen 

Comments

[Paul Rivers]

"And when replacing only two, we recommend installing the new tires in the rear and placing the (older but still decent) rear tires in the front. This may help prevent a spinout or oversteer condition on slick roads. Both these recommendations apply to rear-wheel drive vehicles as well."

Sorry...what?

Isn't it something like 70% of your braking power comes from the front brakes? And aren't those the ones you, you know steer with?

[Daniel K]

Yes, you should be replacing the rear tires. In the case of a blow-out, you would rather have the older tires in the front, rather than risk losing control from the rear. That's where that awesome P.I.T. technique comes from on America's Wildest Police Chases.

[Bombadill]

Paul -
You'd want to put the more worn rear tires on the front because they likely have less traction than the new tires. The article is suggesting you'd rather the front tires have less traction because if the rear tires have less traction you are more likely to have oversteer, and go into a skid. Most people have front wheel drive cars and understand understeer, but not how to get out of a skid.
If you like powerslides or drifting, keep the tires with lower traction on the rear.

[Ron Smith]

Yesterday I replaced a damaged front tire with a new one. Should I have bought two new tires even thought the remaining tire was still very good?

[SteveP]

There are many myths regarding tires and many are repeated as gospel truth with absolutely no scientific evidence.

Obviously, tire are very important, but just look at what comes standard an the same car in differing trim levels - everything from 15" "grocery-getter" tires to low-profile 18" (or bigger) on the same vehicle. Some cars have four same-size tires on the base model, while more-expensive models with have larger wheels and wider tires - sometimes with substantially differing sizes between front and rear. BMW is famous for this - base models get four identical 16" tires and upscales get completely different 18-20" ones (they'll all get the same useless spare, though :-)

I'm sure these are all tested as being safe configurations, but in reality, using differing tires and or treads will result in.. different handling. Not unsafe - different.

A study done many years ago (i.e. scientific evidence) when it was claimed mixing radials and bias tires was a "killer" configuration - proved that it was untrue.

Yes, some setups produce more understeer and some produce oversteer. Mismatched tires on one axle could give more understeer in one direction and less in the other. But none of these effects is anywhere near what we already experience driving different vehicles (large SUV compared to small sporty car) so how can it be "unsafe"? Is there only one "safe" handling response? Of course not.

Tire marketing preys on our insecurity. Take care of the tires you have and replace them when worn with tires of a similar size and quality. And sleep well.

Popular Science - Google Books http://bit.ly/5kQZmn

[Paul Rivers]

"Yes, you should be replacing the rear tires. In the case of a blow-out, you would rather have the older tires in the front, rather than risk losing control from the rear. That's where that awesome P.I.T. technique comes from on America's Wildest Police Chases."

You say "rather than risk losing control from the rear". You don't really have any control in the rear to being with. Your steering is in the front. Your typical car is front wheel drive. Like 70% of your braking comes from the front wheels.

Seems like I would greatly prefer a blowout in the rear, non steering tire than in the front tire.

[Bill]

I also heard that better tires go to the rear to increase traction in the rear which will, in theory, help the car track better in wet conditions.

[Amanda]

I have always been told to put new tires on the front, that having a blow out on a front tire could cause your vehicle to flip.

[Duane Olson]

I have heard so much about replacing tires and everyone always includes that it is best to replace all four tires at the same time. This is not the case...
I have always replaced two tires at a time never four.
No matter what happens every vehicle will be in need of new tires at some time or another
If you rotate tires eventually you will have 4 tires that need to be replaced. This implies that none of those tires are as safe as new tires.
On my car I have 2 practically new tires at all times those tires stay on the rear where wear is minimal, and 2 tires that are nearly new at one point. Those tires wear till I feel it is time time to replace them.
In this scenario only the front tires are replaced and those new tires are installed on the rear of the vehicle then the tires from the rear are rotated to the front.
I get exceptional life from my tires and I can more readily see when it is time for an alignment instead of hiding the problem by rotating the tires