When Should I Add Wheel Spacers to My S550 Mustang?

Factory wheel offsets are not very aggressive, keeping the wheels deep in the wheel well. Offset also dictates whether bigger rim and tire combos will rub, and if road grime gets slung on the side of the vehicle. Installing wheels with more aggressive offsets is one way to go, but wheel spacers will do the trick as well if you like your factory wheels. With wheel spacers, you can fine tune your wheel offset to get the flush look everyone craves. Wheel spacers also add clearance between the wheel spokes and the brake calipers, so they can give you added clearance for big brake kits.

There are a couple different types of wheel spacers. The most common spacers slide over your wheel studs and require no extra hardware to install. You have to be careful when choosing these types of spacers because you need to ensure you still have enough threads to effectively hold the wheel to the hub. Bolt on wheel spacers are one of the safest options. These usually come in thicker sizes, about 1 inch or greater. They install by bolting to the wheel hub, then bolting your wheel to the spacers. The last option is a spacer that comes with longer wheel studs. These require you to replace the factory studs with longer studs, giving your lug nuts enough threads to engage and hold safely.

Hub centric wheels spacers line up to the diameter of the axle hub for a perfect fit. They only require lug nuts to hold the wheel and spacer in place. These are the best choice since they prevent imbalance. Non-hub centric spacers can slip or shift from side to side when you’re trying to bolt the wheel up, and this can cause vibrations similar to an improperly balanced wheel. If you are installing non-hub centric spacers, try to get them as centered as possible on the hub before installing your wheel.

Wheel offset can seem a little complicated at first, but it’s really quite simple. Wheel offsets are based off of negative and positive numbers. The more positive the number, the deeper the wheel will sit in the wheel well. The lower the number or more negative it is, the more the wheel will stick out from the hub. Factory Mustang wheels are usually in the 40mm to 50mm range and sit far in the wheel wells. Lets say you see a friend who has wheels that sit flush, and you want your wheels to sit the same way. You ask him his offset and he tells you they are 30mm. In order to get your factory 48mm wheels to sit like your friend's, you’d have to add 28mm of spacing. You always subtract the spacer size from the wheel offset to get your new effective offset. So a 48mm wheel with a 25mm spacer is equivalent to a 33mm offset wheel.

Wheel spacers work well for a variety of different tasks. You can use them to fine tune your aftermarket wheel offsets, give your sunken factory wheels a great flush look, or increase wheel clearance for a big brake kit. If you’re trying to achieve any of these goals, spacers are an incredibly cost effective way to get those results. Remember, wheel offsets and spacers are nothing more than simple math. To determine your effective wheel offset just follow these steps:

• Determine your current wheel offset
• Determine the size of your spacer
• Convert to millimeters if your spacers are listed in inches (1 inch = 25mm, 1.5 inches = 35mm)
• Subtract the spacer measurement from your wheel offset to find effective offset