Larger wheels offer vehicles a more aggressive attitude and more showmanship, which is why concept cars have king-size rims. They appear to be cool. Whether you choose a larger-diameter wheel as a choice on a new car or as aftermarket wheels for your current vehicle, there are benefits and drawbacks to plus-sizing. 

wheel size

If you upgrade to a larger wheel diameter (say, from 17 to 18 inches), you’ll need new tires to go with it. To maintain enough clearance when driving over bumps and potholes, such tires require a lower profile (or sidewall height), which causes the car suspension to completely rebound and compress.

If the wheel diameter grows by an inch, the tire’s height must drop to compensate so as to maintain the same total diameter. For instance, if your original equipment tire size is 215/65R17 and you purchase 18-inch wheels, the correct tire size for the bigger rims may be 225/55R18. The difference will be the larger-diameter wheel size, lower profile (55 rather than 65), and wider tread (225 millimeters rather than 215). 

If you switch to bigger wheels without considering sidewall height, you risk destroying the wheels and suspension, as well as getting false speedometer readings since the wheels are moving at a different pace than previously. Odometer and speedometer readings should alter just slightly, if at all, by aligning lower-profile tire sizing to larger-diameter wheel size. With lower-profile tires and larger wheels, they’re stiffer and have even less of an air and rubber cushion than previously, increasing the possibilities of damaging the wheel, tire, or both.

alloy wheels

Although larger-diameter tires and wheels ought to enhance high-speed performance and handling, lower-profile tires have a harsher ride and could be noisier than regular rubber.

The added weight of the bigger tires and wheels may outweigh some of the possible performance advantages. An 18-inch tire, for instance, will almost certainly weigh a few pounds more than a 16- or 17-inch tire. That might also apply to a larger-sized wheel.

Because a steel wheel weighs more than an aluminium alloy wheel, the latter improves performance by lowering unsprung weight. However, swapping out a conventional 17-inch alloy wheel for an 18- or 19-inch alloy rim would add weight unless it’s a costly, lighter type.

Larger wheels are more expensive. The larger the vehicle, the more pricey the wheels and tires. If you purchase larger wheels as part of an option package on a new car or as standard features on a higher trim level, the initial investment may be low. However, the additional cost of repairing a damaged wheel or tire might be significant.