How To Measure Wheel Size and Fitment Diameter Offset Backspacing Width Bolt Pattern Lug Nuts

How To Measure Wheel Size and Fitment Diameter Offset Backspacing Width Bolt Pattern Lug Nuts


Brought to you by JEGS. In this video we’ll cover some of the potential
pitfalls you can encounter when ordering custom wheels. How to measure properly to ensure
your new wheels will fit the car correctly. And how to make sure you’re ordering the correct
product for your vehicle. It’s important to always take your wheel measurements with the
tire dismounted from the wheel in order to avoid any mistakes. There are a number of
important dimensions that will affect how the wheel fits on your vehicle and, in fact,
whether it will fit at all. Follow along as we point out the important terms you need
to know to properly select your new wheels. There are five main measurements we’re looking
at today. Bolt pattern, offset, backspacing, diameter, and width. Each of these dimensions
plays a part in whether your selection will work properly on your vehicle. Diameter is the measurement across the face
of the wheel, not including the wheel lips, which are the part of the wheel that helps
to retain the tire in place. Width is the measurement from the inside of the wheel lip,
across the wheel to the other wheel lip. These are the basic dimensions that affect appearance
and what tires you’ll need to buy. There are four different common bolt pattern styles,
four, five, six, and eight lug. And each can be found with several different bolt circle
dimensions. To determine the bolt pattern dimensions for your vehicle, use the following
method. If you have a four, six, or eight lug wheel, measure from the middle of two
holes directly across from one another. Five-lug wheels are measured from the back of one hole
to the center of the second hole. For convenience, JEGS offers and inexpensive template set that
lets you instantly and accurately determine your bolt pattern. The next few steps are very important to consider
when measuring for your wheels. Wheel offset is the dimension from the rear of the mounting
face to the centerline of the wheel. Wheel backspacing is the measurement from the rear
of the mounting face to the back side wheel lip. Both of these dimensions will affect
suspension and brake clearance. There are three different types of wheel offset, positive,
zero, and negative offset. Remember that the offset is measured from the inside of the
wheel’s mounting face to the true centerline of the wheel. A positive offset wheels hub
mounting surface will be shallow, closer to the street side of the wheel. A zero offset
wheel will have a hub mounting surface that is centered in the middle of the wheel. And
a negative offset wheel will be deeper, or having a mounting face that’s closer to the
back side of the wheel than the front side. Confirm the correct bolt pattern to ensure
the wheel will fit the hubs of your car. You must take into account clearance when turning,
clearance for suspension or exhaust parts, and making sure to take your measurements
with the suspension compressed. The vehicle needs to be on the ground and will require
checking these things with the previous wheels and tires on the car. There must be a safe
amount of room between the side wall of the tire and the wheel well opening and any other
potential interference points, both inside and outside the wheel. You can use this Percy
WheelRite Wheel Fitment Tool from JEGS to make the process easier on difficult fitments. It’s also important to select the right style
lug nuts for your new wheels. Some wheels require acorn style 45 or 60-degree seat lug
nuts. While other wheels, typically racing wheels, require mag style lug nuts, where
the shank on the nut protrudes into the wheel. Shank lug nuts come in varied lengths designed
to fit the thickness of the specified wheel. Double check the style and length of lug nuts
your wheels require and make sure you’re also ordering the correct thread pitch for your
vehicle’s wheel studs. If you’re looking to install a new set of
wheels and tires onto your vehicle, a few minutes spent measuring will be required before
placing an order. This will ensure that the wheels you get will turn heads, keep you happy,
and fit right for miles of smiles. Brought to you by JEGS.

Only registered users can comment.

  1. Is wheel offset differential of 10mm a big deal? just asking as I mounted aftermarket rims with a 45mm whereas the stocks are 55mm. Thanks

  2. great video! I'm thinkin about running 18×9.5 offset +22 with 235/40 all around on my scion frs gonna be lowered about 1.5 will there any problems?

  3. The car that I am putting new rims on is a 1971 dart swinger (which is the car used in the video), if anyone wants to tell me the rim and tire size of the wheels on the car in the video that would be helpful. Thanks

  4. The video covers the terms very well although it is rather fast to let it sink in. I believe the only thing they didn't mention is the need for the wheel spokes to clear the brake calipers. In particular large brake calipers that protrude a fair amount(for example, 6-piston Brembo brakes). As the backspace/offset does not assure you of this clearance. It's actually the design/placement of the spokes of the wheel that determine if they will clear. This information may be obtained(usually) from wheel vendor and/or manufacturer. Or alternately from another person that has mounted that exact same wheel with exact same backspace on the car with the same brakes.

    You would be doing yourself a favor by taking the time to review the many videos on wheel measurements. It's not so bad once you understand the concept and effect of changing the offset/backspace.

    Oh BTW…Backspace is typically measured and stated in inches while offset is measured and stated in mm(millimeters). There are 25.4mm in an inch. For example, when the fella below asked if an offset differential of 10mm a big deal, he would know that it represented a little less then 1/2".

  5. My wheels are 16×6.5 Bolt pattern 5×114.3mm Offset 37mm…the wheels i wanna get are 17×6.5 Bolt pattern 5×114.3mm Offset 39mm..would that be okay you think? I drive a 2008 jeep patriot

  6. you forgot about the different center bore sizes. the center bore is very important, most rims are hub centric not lug centric, id be taking this into consideration. hubcentric rings can remedy wheels with a center bore larger than the cars wheel hub center bore, but obviously wont work if the rim center bore is smaller than that of the vehicles hub center bore

  7. I am so confused, so what is the important measurement for rim width? I have "15×8" rims but they are actually 15×9. What i am confused about is if people always go by the actual width or by the bead width, because i am about to install some 235-75-r15 tires and i am reading everywhere that they are not wide enough for a 15×8 inch. But now i dont know if those people are talking about a 7 inch wide rim from bead to bead that is actually 8 inches wide rather than a 9 inch. PLEASE HELP!!

  8. Hi maybe you can help me
    I have a multican suzuki 4×4
    I need a offset wheels so i can use offroad tires
    The stock wheels is 13 inchess

  9. I have a Mercedes My wheel is 16" 5×112 with a 35 degree off set so other
    rims that have the same specs should work on my car?

  10. if i have 15 x 6" or 15 x 6.5" rims, can I use 205/50/R15 or 215/45/R15??.i want it to be look FLAT LOOK and WIDE LOOK which is the best tire sizs for my rim?

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