With the sheer amount of aftermarket wheels on the market for the 2004-2014 F150s
and 2015-2022 F150s
, it's hard enough to make decision purely based on looks and style alone. Factor in arguably the two most confusing parts of aftermarket wheels, backspacing and offset, and you make picking out a new set of F150 wheels outright anxiety-inducing. With all the questions we get on a regular basis about backspacing and offsets, we thought we should probably do an in-depth breakdown of what offset and backspace even are, what different offsets and backspacings mean for your truck, and how backspace and offsets of your wheels actually affect tire fitment. The good news is that F150 wheel backspacing and offset are more complicated on paper than they are in reality, though it can be difficult to grasp it all spatially, and there's really not a "wrong" answer to F150 wheel offsets, just some things you ought to know before taking a dive into the F150 wheel market.
What is Wheel Offset and Backspace
Before we get started on how offset and backspacing actually work on your F150, we have to understand what these two things actually are and how they play off each other to a pretty huge extent. We'll start with backspacing, since backspacing isn't as reliant on other aspects of the wheel (more on that in a bit). Backspacing
is the measurement of the hub mounting surface to the back of the wheel. This means that wheels with higher backspacing result in the wheels tucking MORE
under the wheel well. Wheels with lower backspacing tuck LESS
under the wheel well and push out farther from your truck. Backspacing is affected by wheel width and offset, but backspacing alone is a good metric of roughly where a wheel will sit and if you'll clear suspension mods like UCAs and the knuckles on lift kits with a given wheel and tire.
As much as most folks emphasize offset when talking about wheels, offset alone is actually a much less useful specification than a lot of people realize. Offset
is the measurement of the hub mounting surface versus the CENTERLINE of the wheel. A wheel with a positive offset will have its hub closer to the outside of the wheel, while a wheel with a negative offset will have the hub closer to the inside of the wheel. Like with backspacing, a wheel with a higher offset will have MORE
tuck under the wheel well, while a wheel with a lower offset will have LESS
tuck and stick out farther from your truck. HOWEVER, since offset is calculated based off the centerline of the wheel, you also need to know the wheel's width in order to actually figure out how a wheel will sit on your truck. For instance, you can have two wheels with the exact same offset, but if they have different widths, they'll sit differently and have different tire clearances which could potentially be a problem. As an example, a 20x9" wheel with a +12mm offset has a backspace of about 5.47", but a 20x10" wheel with a +12mm offset has a 5.97" backspace, giving them different clearances with your F150's wheel wells and suspension, which can potentially be an issue. While offsets can be handy when comparing wheels of the same width, alone, it's not as useful as backspace.
How Offset and Backspacing Work on the F150s
With boring definitions out of the way, we can actually get the meat of the situation and how wheel backspace and offset work on the F150s. The stock wheels on most F150s have a pretty high 6.5" backspace with high offsets that range from +44mm to +55mm depending on the width of the wheel (again, this is why offset alone isn't a great spec). In general, most aftermarket F150 wheels have less backspacing and offset than stock, which push them out a bit from the truck's body and wheel wells. Granted, there's still a pretty huge range of backspacing options available, and there's plenty or reasons why you may want to go with a wheel with a high offset and backspace and vice versa.
Why you may want High Offset and Backspace Wheels on your F150
Wheels that have pretty high backspacing and offsets get kind of a worse rap than they really deserve, though they can cause some issues with wide tires and certain suspension modifications. The biggest reason why you may want wheels with a high backspacing and offset is that they do stay tucked under the wheel well. Keeping your choice of tire within or in line with the wheel well is absolutely critical if you live in an area that doesn't allow you to have your tires outside the wheel well. As a secondary benefit, if your tire is under the wheel well, your truck's sides and love handles won't get as dirty when you're ripping around. Wheels with a bit more backspacing also tend to let you clear slightly taller tires without trimming than wheels with lower offset and backspacing.
Why you may want Low Offset and Backspace Wheels on your F150
Wheels with low offsets and backspace are by far the most popular choices for F150 owners, and there's plenty of reasons why. First, most people don't live in areas that have strict laws regarding how far tires can stick out, and giving your F150 a big, bold look is never a bad thing. More importantly, wheels with low backspacing and offsets will allow you to use pretty wide tires while still clearing certain suspension modifications. Aftermarket upper control arms, lift kits with larger knuckles, coilovers with remote reservoirs, and others have backspacing requirements in order to clear wide tires (usually 12.50", but sometimes others), and wheels with fairly low backspacing and offsets may be your only option. That being said, wheels with low backspacing and offsets paired with pretty wide and tall tires will likely require some valance trimming in order to fit on your truck, which is something you'll need to keep in mind.
How Offset and Backspacing Affect Tire Fitment
One of the most important factors when picking a wheel with a particular offset and backspacing is what tire size you're planning to use, since offset and backspacing play a huge role in potential tire fitments. A tire with certain heights and widths may clear just fine on a wheel with fairly high backspacing and offsets, but may have issues on a wheel with low backspacing and offsets. The reason why has a lot to do with the curvature of the F150's wheel wells and how wheels with a low backspace push the apex of the tire out to where the wheel well starts to curve back in. This means that taller and wider tires may need trimming depending on the wheels you choose. In general, wheels on the higher end of the offset and backspace spectrum will let you clear bigger tires without trimming (though you will run into clearance problems with certain mods, like we already mentioned), while wheels with lower backspacing and offsets will limit you a bit on tire sizing unless you're willing to trim.
Wheel Offset Chart and Final Thoughts
In the end, wheel offset and backspace are actually pretty simple concepts, but how they interact with your F150 and your choice of tires can get pretty complicated in one heck of a hurry. The good news is that we here at Stage 3 are here to help you out. We've put together a ton of different F150 builds over the years using all sorts of different wheels and tires of different widths, backspacing, and sizes. If you ever need some help, just give us a call directly at 623-434-5277 or email us at [email protected]
Also check out our handy offset chart below that shows what different offsets look like on a wheel with the same tire and width for a more visual example.