BMW Wheel Spacer FAQ: Everything You Wanted To Know About Spacers

This page consists of everything we have learned about wheel spacers for BMWs. A lot of this info also applies to other makes as well. It's a very long and comprehensive collection of data, tips, and technical info. We hope it's useful to you but if you should have any further questions, please call or e-mail us.

Jump To:
1. Why Use Wheel Spacers?
2. What Size Should I Use?
3. How To Measure Wheel Gap
4. Wheel Bolts
5. Wheel Studs
6. Secure Fitment
7. Big Pad Wheel Spacers
8. Measuring Hub Depth
9. Wheel Offset Issues
10. Hardcoating vs. Anodizing
11. Additional Info

Why Use Wheel Spacers?
  • Appearance. You want to push the wheels out for a better stance and more aggressive look. This is totally subjective to your personal tastes. And we can't tell you what to like...
  • Clearance. Many wheels are not compatible with big brake kits. The spoke of the wheel will scrape the new brake caliper and you need a wheel spacer to push the wheel spoke away from the caliper.
  • Correction. You may have bought a set of wheels that don't have the correct offset for your car. The offset may be too high, resulting in the wheels sitting too far inward. This is both ugly and incorrect as the tire can now rub on the inside wheel well, or on suspension components, etc. A wheel spacer will push the wheel out and 'correct' the offset.
  • Handling. By spacing the wheels further apart, you can make the car more stable and corner better. You can gain a similar effect as adding a wider wheel without the added weight and expense.

What Size Should I Use?
This is one of our most commonly asked questions. Unfortunately, it has no easy answer. Picking a spacer that meets your needs is not as easy as it sounds. If it were easy, we'd all be using the same size. There are a few different reasons why people need spacers so every situation ends up being different. But every situation can be resolved by finding out how much available space you have to work with. That means measuring the tire-fender clearance. This empty space will likely be your spacer size. You don't want to exceed the empty space because that will lead to the tire rubbing on the fender. And you don't want to get too thin of a spacer because that may not meet your needs.

Turner Motorsport may be the biggest BMW wheel spacer dealer in the world. As such we have learned not to make assumptions on spacer size. Every situation is different and the best advice we can give is to measure your car. It's tempting to listen to what everyone else is running but unless they have your exact wheel, exact tire, exact brake rotor, exact suspension, and exact suspension settings, no one can tell you what spacer size to use. They can only guess... Please keep in mind that spacers that have been installed and tested cannot be returned. This is to be fair to the next customer who expects new, top quality parts from us. Which is all the more reason to be precise about what size you can install.

Here are some easy ways to measure your wheel gap -
The outside of the tire sidewall is usually the widest point of your wheel and tire (unless the tires are 'stretched' across the rim. With the tire/wheel on the car and the car on the ground at its desired ride height, place a straight edge or ruler between the outermost tire spot and the inside of the fender lip. The distance is your wheel gap and your spacer size. This is the max spacer size so it would be a good idea to choose a spacer one size lower to account for suspension travel.

Old-Fashioned Tape Measure
With the car on the ground, hang a piece of masking tape from your fender. Stick a quarter or a nickel on the end so that it hangs straight down. Next measure in from the masking tape to the outside edge of your tire. This will tell you how much space you have until the tire would contact the lip of the fender. Pick a spacer that is slightly less than this measurement. This will ensure the tire does not rub on the fender lip.

Even More Old-Fashioned Rulers
Same as the method above but if you don't have masking tape to hang from the fender, you can use a straight-edge or ruler and another ruler or tape measure. Gently hold the straight-edge from the bottom of the fender lip. Measure in to the outiside of the tire. The gap between the straight-edge and the tire is your available clearance. Choose a spacer size slightly less than this dimension.

Wheel Spacer Test Fitment Kit
What if you had one of each spacer size on hand to play with? You can swap spacers in and out until you achieved the perfect stance or the right amount of clearance. ECS Tuning put together this slick Spacer Fitment Kit that includes a 1mm, 2.5mm, 5mm, 10mm, and a 15mm spacer along with a variety of wheel studs and nuts. This is a universal kit that they sell for BMW, VW/Audi, MINI, and other makes. The spacers themselves are for test-fitment purposes only - they lack the hubcentric lip and all of the bolt holes required for a final install. This Spacer Fitment Kit is offered for rental or for purchase. Click here to order.

Wheel Studs and Washers
For this method, you would purchase at least two wheel studs to thread into the hub and corresponding nuts to lock the wheel down. You can buy generic wheel studs at any auto parts store (bring one of your stock wheel bolts for them to match up) or purchase a couple from us (link to Turner 90mm studs). Remove your wheel and bolts. Thread the studs into the hub. Place washers down the stud to the hub. Slide the wheel over the studs. If it makes contact with the caliper or suspension, add more washers. Once the clearances are set, lock the wheel down with the nuts. Lower the car to the ground and roll - don't drive! - the car back and forth so the suspension will settle. Check your clearances again and also for tire-fender contact. Adjust if necessary. The end thickness of your washers will be your minimum spacer size. If you have space left over before the tire hits the fender, consider going with an even bigger spacer for improved looks.
Remember to remove your studs or install them the proper way before driving.

Studs and washers installed in the hub. Pictured is a BBS 90mm stud and 5 washers (roughly 15mm).

Studs and washers installed with the wheel.

BMW Wheel Pin and Washers
If wheel studs are not available to you, you can use the factory BMW wheel pin tool in your tool kit. More than one pin is recommended. This method does not allow you to set the car on the ground as the wheel pin will not support the weight of the car and there is no way to fasten the wheel to the hub. Don't even try it! Remove your wheel from the car. Insert the pins into the hub. Slide M12 sized washers onto the pin down to the hub. Slide your wheel onto the pins until it contacts the caliper, suspension, etc.. Add washers until the wheel sufficiently clears. The thickness of your stack of washers is the size of your spacer.

Factory BMW wheel pin tool installed with washers.

Wheel Bolts
Remember that every wheel spacer needs a longer wheel bolt or stud. It's amazing how many bolts we sell without spacers so this fact is getting lost on a lot of people (or their supplier is leaving out critical information). The correct length wheel bolt is your stock bolt + the thickness of your spacer. As a general rule, we consider the stock BMW length bolt to be 25mm as measured from the base of the cone seat to the tip, including all threads and shank. So a 10mm spacer will require a 35mm wheel bolt. However, we have seen a range of stock BMW bolt sizes from 25 to 28mm. A bolt that is too long will interfere with other parts inside the hub (ABS sensors, parking brake mechanism, etc). Existing wheel bolt offerings may vary by 2-3mm but you can trust us that we have extensively researched, sold, used, and tested the fitments on all of the spacers and bolts that we sell. If a situation comes up where an unusual application is needed, we have many sizes to offer.

Use this chart if you're not sure if your bolts are correct for your spacer size and application. BMW bolts are 12x1.5, 14x1.25, or 14x1.5. You can tell if you have enough of the bolt installed in the hub by counting the number of turns or checking the threads for their engaged length (the threads will be discolored or coated in grease).
Wheel Bolt Type Safe Engagement Length Number of Turns
12x1.50 approx 10mm 6.5
14x1.25 approx 12mm 9.0
14x1.50 approx 12mm 7.5

Wheel Spacers With Wheel Studs
Wheel studs protrude from the hub and help to locate the wheel to the hub. A wheel nut (lugnut) would then be used to fasten the wheel to the hub. The issue with using them with spacers is that it can actually push the wheel out too far, leaving you without enough threads to securely fasten the wheel nut. Here are some things to keep in mind when choosing studs and spacers -
  • length of available stud sticking out from the hub
  • brake rotor hat thickness (varies)
  • wheel bolt bore depth (the depth of the hole in the wheel) (varies)
  • spacer size
  • number of turns on your wheel nut (6.5 turns or 10mm for a 12x1.5 stud/nut)
For instance, a Turner 75mm wheel stud usually has enough room left over to use a 10mm spacer. However, a big brake kit may have a thicker rotor hat than stock which would reduce your available space on the stud. As well, the thickness inside the bolt hole can vary a lot as well. A thicker wheel will reduce your available threads. The solution here is to use a longer wheel stud.

Not all wheel studs are created equal. We don't take a manufacturer's generic wheel stud from their catalog and call it our own. Turner Wheel Studs are designed to our own specifications and manufactured for us exclusively. Beware of cheaper studs on the market! W