Wheels: Measure Twice, Buy Once

Learn The Right Way To Measure for Wheel Size Before You Place An Order

So, you want a new set of wheels for your hot rod or muscle car. That’s totally understandable because wheels go in and out of style all the time.

New sizes and wheel styles are always welcome in the automotive aftermarket, but it’s always important to measure your car before making a big purchase. The last thing you want is to have clearance issue with your brand new tires or wheels!

Every car is different, so picking wheels isn’t quite as easy as it seems. You should definitely do your homework before making an order, and it will pay off with a smooth transaction and an easy installation when it’s time to get rolling.

Most gearheads want the largest possible tires and wheels on their ride, so measuring for maximum width and back spacing is an important part of the selection process.

Bolt Pattern

The first step is to determine the size of the bolt pattern, also known as the bolt circle. Just as a quick reference, older cars (pre-WWII) had much larger bolt patterns, but today’s most common bolt patterns are 5×4.75 and 5×4.5.

As a general rule of thumb, a 5×4.75 pattern is used on most GM passenger cars, while the 5×4.5 applies to many Ford and Mopar applications. With a five-lug pattern, measure from the outside edge of the first stud to the center of the third stud to find the correct measurement.

Measuring center to center will not provide accurate results on five-lug patterns. However, all four, six and eight lug patterns are measured center-to-center on the studs.

Backspacing

Another measurement to consider is the wheel’s backspacing.  To measure backspacing, place a straight edge on the inside lip of the rim, and then measure the distance between the mounting flange and the straight edge.

There are several ways to measure your vehicle for tire and wheel clearances, but a measuring tape and a straight edge seem to be the most effective. Always check for turning radius up front, and account for tire sidewall bulge. 

If there’s anything that might get in the way, be sure to account for it when measuring for rim spacing and give yourself a couple inches of wiggle room on inner side of the rim for sidewall bulge when the tire is inflated.

Rim or Wheel Width

Wheel and tire dimensions can make or break your vehicle’s appearance, so get it right the first time by measuring for the correct diameter, width, backspacing and bolt pattern.