It’s highly recommended to use the exact tire size recommended for your car. However, in a pinch the tire width and aspect ratio can be changed slightly and still fit on your rim. Although this will still work, keep in mind it may have adverse effects on the performance of your car. Also bear in mind that the rim size should never be changed.
As a general rule of thumb, we only recommend changing the width by 1cm either side of your cars preferred size. For example, a car rim designed to take a 245mm tire width, could comfortably accommodate a tire between 235mm or 255mm in width.
Similarly, we only recommend changing the aspect ratio by 5% either side of your cars preferred size. For example, a car designed to take a 60 aspect ratio tire could also fit a 55 or 65 aspect ratio.
In winter it is very common to ‘downsize’ tires – this is making the width slightly smaller. A narrower tire will help with traction in snow. For example, if your car carried a 215/60R15 tire, you could use 205/60R15 and see increased performance in snowy conditions. This is known in the industry as ‘downsizing’.
