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A sweet set of new wheels is a major purchase, but once you get the old stock wheels (or worse, someone else's idea of "nice wheels") off of your car, it's worth every last cent, isn't it? A custom set of wheels is that bit of personality that can perk up a pickup truck, give a car a bit of muscle, or if you're legitimate about your weekend activities, can make the difference between performing and just spinning your wheels. But do you know how to actually go about picking the correct set of wheels for your new ride? It's not as easy as looking at your Camaro, picking the style of wheel you like, and choosing a 15x8 dimension. Many things need to be taken into account if you want to get that perfect look you have in your head. And on late-model vehicles that have sensors and other equipment in the way, there's quite a bit more to fitting out the wheel well than just picking the biggest wheel and tire package that doesn't bash into the fender lip.
We wanted to do something a little bit different on this 2015 GMC Sierra 1500 Denali. Nothing against the factory-style 24-inch wheels that were put on by a previous owner, but they didn't visually pop and when driving around, any road rougher than glass transmitted every last little bump, pebble and seam through the cabin and directly to the driver's spine, taking away from the luxury-truck theme of the Denali. So the decision was made to change out the Denali's steamrollers and rubber band tires for a set of 20x9 Rev Wheels OE Replica 586 series wheels (586MB-2908327) and 275/55R20 Toyo Open Country A/T III tires. It might seem like a step down, but the increase in tire sidewall over the 24-inch combination means that there isn't a physical loss of rolling stock height. Seems easy enough to have made that decision, right? Follow along and we'll show you what all went into the selection process for these wheels.
Our 2015 Denali's rolling stock looks quite impressive at first glance, but it's not perfect. The thin tires translated to a harsh ride quality and there was tire rub when the steering wheel was turned full-lock.
When ordering wheels, keep in mind what kind of room you have to work with. Even before you break out the tape measurer, seeing where the potential impact points are located will help you keep wheel height and width options in check.
Unfortunately, whoever put the 24-inch wheels on our Denali didn't take that into account. Our front tires were rubbing against the sway bar at full steering lock.
Just like the front suspension, the rear suspension requires a look for potential interference points. Look for things like soft brake lines, sensors, suspension mounting points, the distance between the hub mating face and the leaf springs or control arms. In our Denali's case, everything would be clear of a 20-inch wheel by sight. But that doesn't mean we're in the clear just yet. Time to break out the measuring tape!
Let's first discuss hub-centric versus lug-centric. Hub centric wheels, like the 2005-era Ford Mustang GT "split-spoke" wheels on this 1980 Ford Mustang Ghia, are designed to match the center bore of the vehicle's hub. Since this Mustang's five-lug swap included stock Mustang parts, these wheels mate up perfectly to the hub and center on the bore. Compare that to the chromed trailer wheels mounted on this 1983 Imperial, which are lug-centric. The lug holes are the centering point, not the hub. This allows the hub to be larger to fit a wider variety of applications. Hub-centric rings can make lug-centric wheels work like hub-centric wheels by slipping over the center hub bore and filling the gap between the hub bore and the wheel bore.
Measuring wheel width doesn't mean edge-to-edge. It means from bead point to bead point on the barrel of the wheel. In the case of this particular example, you would have a 10-inch wide wheel, but you might have 11.5-12 inches of total width edge-to-edge. And that might be enough to cause some rubbing.
Backspacing and offset might be the most misunderstood measurements when it comes to wheels. The quick explanation: Backspacing is measured from the mounting surface to the back outermost edge of the wheel in inches, and offset is measured from the mounting surface to the centerline of the wheel barrel in millimeters. Most modern cars use positive offset, which pushes the hub mating surface outward. Vice-versa, many old-school muscle cars used a lot of negative offset for that deep-dish mag look.
Before you order your wheels, you also need to know what bolt pattern you are ordering for. In the case of our Denali, you simply pick two opposing wheel studs and measure from the center to the center. This measurement, when shopping, can be represented in lug count x inches or lug count x millimeters. Our Denali uses a 6x139.7mm, or 6x5.5in bolt pattern.
Measuring out an odd-numbered set of wheels is a bit more tricky. For five-lug wheels, the easiest route is to measure from the center of one lug to the outer edge of another on the opposite side of the bore, as demonstrated on this Ram Rebel's wheel. This is a 5x5.5" (5x139.7mm) bolt pattern. A more accurate method is to measure the center-to-center point of two adjacent studs, then multiply by 1.4.
Finally, make sure you understand the total height of your wheel and tire package and how that will affect areas such as your fender lips and wheel well liners. Our Denali had plenty of room, but if you're looking for that closely tucked look or are trying to fit significantly larger wheels and tires, this is something to be careful of. Nothing ruins your day quite like a wrinkle in your fender once the tire kisses sheet metal!
We had to try this comparison: this is a mounted and balanced wheel and tire package, sitting in front of the original 24-inch wheel and tire package that is still mounted on the GMC. There is no size loss for the wheel and tire package, even with the smaller wheel, thanks to the thicker sidewall.
With proper measuring and careful selection, you will have no trouble picking the right wheels for your ride. The REV Wheels OE Replica 586-series look fantastic on our Denali, and the Toyo Open Country III tires both bite into the mud, and are able to fling away in the dirt, yet on the road they don't make noise until you start digging into a corner. The ride has improved over the 24-inch wheel combo and there is no tire rub at full lock.