5,000-Mile Report: Rotation Consternation
I’m still not sure I did the right thing.
Choosing the XC90? Oh, no. That was the right thing. I’m talking about rotating tires.
This week, the XC90 logged its 5,000th mile. For the most part, it has performed flawlessly, and I’ve been delighted by many of its details: the quality of the Harmon-Kardon sound system, the convenience of Apple CarPlay, the way the engine’s automatic stop-start works so smoothly at red lights and stop signs, the pleasure of a heated steering wheel in winter and cooled seats in summer. Did I experience any problems? Well, once, when I started the car, the Sensus infotainment system didn’t boot up right away. I turned the car off, restarted it, and all was fine. It was, knock on wood, a 10-second inconvenience in six months of ownership. Average gas mileage for the life of the vehicle has ticked up to 21.1 mpg from 19.2 at the 1,000-mile mark. I’d estimate that 80% of those miles represent driving around town.
With 5,000 miles on the odometer, I considered it a good time to take the XC90 to my local tire shop, just down the road, to have the tires rotated. And that’s where I’m not sure I did the right thing.
As any Volvo owner who’s cracked the owner’s manual knows, Volvo does not require, nor even recommend, rotating the tires of its vehicles. However, it says that if the owner does wish to rotate the tires, it should be done in such a way that the tires are always rotating in the same direction once remounted. In other words, tires on the right must stay on the right and tires on the left must stay on the left. You only rotate between front and rear on the same side. This is Volvo’s guidance whether your vehicle has directional tires or not. (Directional tires are designed to only rotate in one direction, which is marked on the sidewall. The Pirellis on my XC90 are not directional.) Volvo further says that if tires are going to be rotated, it should ideally be done first at 3,000 miles, and then every 6,000 miles thereafter. That’s not terribly convenient. Since Volvo recommends routine maintenance at 10,000 miles, I’m opting to go with rotating every 5,000 miles. Every other time, that will fall during regularly scheduled maintenance.
But here’s the rub. We’ve owned 4WD or AWD vehicles for most of the past three decades, and we’ve always rotated them the way most tire manufacturers recommend: fronts get crisscrossed to the rear, and rears get moved to the front staying on the same side. This way, you don’t have the tires always rolling in the same direction, such that the outside tread wears faster than the inside from negotiating turns. And that should extend the life of the tires.
When I questioned my local dealership about this, I was told that when their shop rotates tires, they simply look at how the tires have been wearing and mount them wherever needed to help balance out treadwear—even if that means moving them to the opposite side of the vehicle.
Then I consulted with my local tire shop, which was going to be doing the work on this first go-round. At first, the owner felt it would be okay to ignore Volvo’s recommendation. Then he turned cautious and said you know what, maybe we should do as Volvo advises. And that's what we did.
I can’t imagine my tires aren’t going to wear faster this way. I and I really can’t imagine what terrible things might have happened if I’d gone ahead and crisscrossed the front tires to the rear of the vehicle. I’d read discussions on the internet talking about how direct tire pressure monitoring sensors might get mixed up if you crisscross, but Volvo apparently doesn’t use direct sensors anymore; rather, it uses an approach that calculates air pressure using the ABS system.
Scrounging around on the internet some more, I found several discussions on this topic at Swedespeed, another Volvo enthusiasts’ website. One of the members there had somehow found this documentation on the subject from Volvo, said to be in the form of a Volvo Service Manager Bulletin. Bear in mind, this was posted in November 2010, long before the current generation of XC90 was introduced with the 2016 model year:
Tire Rotation
As suspensions and drive trains evolve, so do vehicle manufacturer recommendations for tire rotation.
Volvo's recommendations have always had a technical basis, while leaving some latitude for customer preference. Presently, for current models, Volvo has no recommended tire rotation. Because this represents an evolutionary policy, customers may need the guidance of a Volvo service advisor to help them understand the performance and handling tradeoffs that come with tire rotation.
Benefit of Tire Rotation
On a front-wheel drive car, the demands placed on the front wheels during acceleration and cornering can mean a dramatic difference between front and rear tire tread wear. Without periodic tire rotation front-to-rear, the front tires will typically require replacement sooner. The primary perceived benefit of tire rotation is that front and rear tires will wear down at about the same average rate. In absolute terms, four tires will not last any longer this way. It becomes a customer choice between replacing two tires sooner and replacing all four tires later. However, with all current Volvo models, Volvo believes that numerous technical, performance, and handling benefits outweigh any perceived benefit of tire rotation. Following are some of those benefits.
Benefits of Not Rotating Tires
Braking Stability Performance
During hard braking, braking on a slippery road, or braking in a curve, good rear tire tread may help you avoid oversteer. Oversteer is when a turning vehicle wants to keep turning because of momentum and dynamic forces on the vehicle suspension. Volvo stability systems are all designed toward reducing or helping a driver avoid oversteer. Still, all things being equal, having more rear tire tread can contribute to reduced oversteer. Without rotation, the rear tires will naturally wear more slowly and have more tread.
Tread Set
As tires age, the tread adopts an angular set, based on its angle to the road surface. For vehicle handling reasons, front and rear tread angle is not the same. If tires are rotated, the tread will eventually set at an angle somewhere between what is optimal for a front or rear tire. Although vehicle ride, handling, and road noise may still be acceptable, they may not be optimal. Additionally, an infrequently or irregularly rotated tire may result in tire noise, faster tire wear, and unpleasant changes in steering feel and vehicle handling.
Driving Performance
A tire that can fully adapt to its position will generally provide better steering feel, lower tire noise, and better fuel economy.
Suspension Wear Diagnostics
Every vehicle's suspension needs periodic inspection and maintenance. A tire's tread wear pattern can be an aid in detecting and diagnosing a suspension problem. Each tire, if left in place, tells a story about its place in the suspension. Tire rotation, on the other hand, can mask a developing problem. Early detection is very important, because suspension problem can worsen tire wear, and reduce vehicle performance, handling, stability, and fuel economy.
So, I’m not sure if I did the right thing. I do know this much. If I have any problems with the vehicle down the road, we won’t be able to blame it on not following Volvo’s recommendations on how to rotate the tires.
5,000-Mile Numbers
Average mpg: 21.1
Problems: none
Maintenance costs: $0
