Some vehicles have different front and rear tire sizes. In vehicles where this is the case, you must avoid tires with a directional tire tread. Here’s why.
On most cars, the tires on all four corners are the same size. They have the same width, aspect ratio, and diameter. However, this is not true of all vehicles. Case in point the new Volkswagen ID.4, which has trims in which the front and rear tires are not the same. This is often called "staggered" tire sizes. What makes the ID.4 unusual is that it is not a performance vehicle.
Automakers have long opted to use different tire sizes, front and rear, so that the driven wheels are a bit more capable of handling the traction and torque demands of its two-wheel-drive powertrain. On performance cars, this has made some sense. The vehicle ends up being a bit more balanced in its handling when driven near its limits.
What is changing is that electric vehicles now offer tremendous torque. Much more than modern conventionally-powered vehicles. Combine this with two-wheel drive, and the results are that the vehicle can be a bit unbalanced in certain circumstances. To help manage this, automakers may adopt differing tire sizes, front and rear.
This is all fine until the first time a tire rotation is scheduled or required. When the time comes, the tires can only be swapped from side to side, not also front to rear. This limits the options one has for tire rotation but is not a big deal. Particularly since with most performance vehicles, the expectation is that tires are not going to last as long as on a conventional car anyway.
The difficulty to avoid is a replacement tire that has a directional tread design. One of the most popular tires today is the Michelin CrossClimate2. This all-weather tire is, at its core, an all-season tire, but it does have a 3-Peak-Mountain-Snowflake stamp signifying it is capable of severe snow duty. For this reason, and many others, it is a very popular tire for folks to adopt when it comes time for the first tire replacement of the vehicle’s life.
The potential problem is that this tire has a directional tread design. It can only roll one way (except when backing up at slow speeds, of course). What this means is that the tires can only be rotated from front to rear. Specifically not back to front. Do you see where this is headed?
On a vehicle in which the tires are staggered in size front to rear, the only option for rotation is side to side. If you mistakenly purchase directional tires for such a vehicle, they can never be rotated. This will minimize your treadwear and will shorten the life of the tire dramatically.
If you have any tire tips, please place them in the comments below. We are always interested in new tire topics to explore.
Image of Michelin CrossClimate2 tire by John Goreham.
John Goreham is a long-time New England Motor Press Association member and recovering engineer. John's interest in EVs goes back to 1990 when he designed the thermal control system for an EV battery as part of an academic team. After earning his mechanical engineering degree, John completed a marketing program at Northeastern University and worked with automotive component manufacturers, in the semiconductor industry, and in biotech. In addition to Torque News, John's work has appeared in print in dozens of American news outlets and he provides reviews to many vehicle shopping sites. You can follow John on TikTok @ToknCars, on Twitter, and view his credentials at Linkedin
Re-Publication. If you wish to re-use this content, please contact Torque News for terms and conditions.
I did some research. If you
I did some research. If you stand a tire between your legs the left and right sides of the tire are the same regardless of a directional tread. The metal wheel on which the tire is mounted is not symmetrical: the inside and outsides differ. So if you have a tire with a directional tread on it then if you leave the tire on that wheel you are indeed constrained not to just move it over to the other side of the car (back or front) if you want to preserve correct direction of tread. But if you take all the tires off the wheels and swap tires side to side back and front you can rotate both back and front tires side to side separately front and back while preserving correct tread direction. In my case I do not have to even pay any extra for removal of tires from wheels because my practice is to have a single set of wheels and to swap summer and winter tires with the seasons. I drive the sort of distances that require no more rotations than is afforded as an opportunity with my seasonal tire changes. So I would not need to be concerned if buying an ID.4 or Audi q4 e-tron, etc.
For a long time the
For a long time the importance of tire rotation has been stressed. Michelin’s new directional tires have gotten favorable reviews, but In many areas there is no need for a good-in-snow tire. I’m not buying Michelins, or any directional tire.
" I’m not buying ... any
" I’m not buying ... any directional tire."
When GM put the first retail Goodyear Gatorback symmetrical directional tread pattern tires on Corvettes it was thought to be hip and cool high technology. Corvette owners soon tired of the costly regular tire rotation processing. ALL 4 tires removed from ALL 4 wheels and then having to remount ALL four tires to the proper wheel for each individual wheel location on the car. Shops were charging anywhere from $20 USD to $40USD to dismount, remount, and rebalance each tire on each wheel. Somewhat more recently Michelin tried to get trucking companies to buy into the symmetrical unidirectional treaded tires. The trucking companies have basically refused to change to those as the cost of doing regular tire rotations for each 18 wheel tractor-trailer combination is far too costly for the minimal benefits gained.
Can you not just square up
Can you not just square up the tire sizes on the ID4, and install the front-size all the way around?
You probably could do that,
You probably could do that, but you would have at least a slight loss of the balanced handling feeling of the car. The rear tires sized the same as the front tires would be working harder to keep the rear of the car stable through a turn. : 235/55-19 Front 255/50-19 Rear