It’s a choice of performance and aesthetics to plus-size tyres and wheels. You can subtly or dramatically affect the curb appeal of your vehicle by changing its profile. It can also be a choice to increase performance as well as increase the cornering ability and shorten stopping distance by increasing the width of the tyre while creating a shorter sidewall.

Plus sizing has increased in popularity of late, but the practice has been around since the 1970s, when the fitments for cars were either +1 or +2, allowing drivers to upgrade by one or two inches of wheel diameter

Plus Sizing Tyres & Its Effect on Your Vehicle

Today, the far greater trend leans toward wheel diameters. And along with demand, of course, comes a healthy selection of tyres to fit on larger rims. Ground clearance, space within the wheel well, speedometer readings, traction, stopping distance, drive line, turning radius—these are all affected by plus sizing. Not to mention also causing issues with any of your Advanced Driver Assist Systems (ADAS) such as anti-lock brakes, traction control, adaptive cruise control and others.

So be sure to weigh the pros and cons before you embark on radically altering your vehicle’s tyre and wheel size.

How Is Plus Sizing Tyres Done?

Plus sizing is done by selecting equivalent overall tyre diameters and load capacities to your original equipment—by pairing lower profile tyres with larger diameter wheels. That way your speed and load rating will still meet the requirements set out by your vehicle’s manufacturer. For each inch you increase the wheel diameter, you must increase the tyre’s width and decrease its sidewall height. The rule of thumb is to increase tyre width by 10 mm and decrease sidewall height by 5% to 10% for every 1-inch increase in wheel diameter.

The Pros and Cons of Plus Sizing Tyres

The advantages of wider tyres include shorter breaking distances, better acceleration and steering response. The disadvantages include cost, stiffer sidewalls (which leads to a more rigid ride), and lower profile tyres being more prone to damage by road hazards such as potholes. And any improvement in handling usually reaches diminishing returns beyond what’s gained by a +1 upgrade. But for those who love the look and performance, that’s a small price to pay.

Consider plus sizing as a custom job. When having it performed by your local shop or car dealership, request that an experienced tyre installer do the work. Look for packages that cover the entire installation process, including labor and equipment. You’ll want a guarantee of service that covers damages that may result in your vehicle as a result of the work. And remember, the more extreme you plus size, the more extreme the risk in terms of wear and tear on parts and diminished tread life.