Three Problematic Wheel Fits
As consumers seek out ways to customize their vehicles, experimenting with aftermarket wheels has become standard. But those customizations, if not done properly, can lead to serious wheel fit problems that affect the handling of the car and can even put the consumer’s safety at risk.
With more than 20,000 active SKUs for wheels, and another 10,000-plus SKUs for tires, the experts at Tire Rack Inc. have diagnosed a lot of those problems. Woody Rogers, product information specialist, outlines three of the most common.
How the wheel fits onto the vehicle affects more than its looks. Domestic sedans like Buicks have original equipment wheels with a conservative fit, meaning the wheels clear the plumb line of the fender by several inches. More sporty vehicles, such as the Mustang GT, show a more aggressive fit straight from the factory. The wheels are pushed out more to fill the wheel well. It’s that sporty look with a lower offset that reigns in the wheel aftermarket, Rogers says, but it’s not limited to performance vehicles.
The trouble is that adjusting the offset to an extreme can affect how the car handles.
“I’m beginning to alter the handling characteristics of the car, maybe not from an unsafe standpoint, but it sure is going to start driving funny at some point,” Rogers says. “The steering feel is no longer the same as it was tuned from the factory. That can have a negative impact for the consumer.
“They may not realize what is happening, or what’s the root cause. They may blame it on the tires. They may live with it, but over time they’ll say it’s just not right. Not everyone perceives things right away, but given enough time even the least attentive driver will pick up on small details.”
The delayed recognition causes trouble down the line for the consumer, and for the tire or wheel dealer. The consumer might only realize the difference in handling a couple weeks later, or a month later. They might not return to the dealer and mention anything until it’s time for a tire rotation or some other regular maintenance. By then, they’re not happy, even though they may have driven hundreds or even thousands of miles on the tires and wheels. “It snowballs into a worse situation,” Rogers says.
There are several varieties, but still two basic shapes of lug hardware to fasten a wheel onto the suspension – a conical straight seat or a ball seat. No matter what, they are not interchangeable. Ever.
“If you cross pollinate those, if you use the wrong hardware on the wheel, you permanently damage the wheel,” Rogers says. “If I didn’t put the right hardware on, it won’t mate with the wheel correctly. You can’t fix that, other than putting on a new wheel.”
Incorrect hardware puts the consumer at risk, because the wheel might not stay fastened, and once it starts to come a little bit loose, it loses its grip and the wheel falls off quickly, Rogers says.
In addition to that basic hardware, using spacers and adapters to force a wheel and tire to fit onto a vehicle also is problematic. “We see spacers and adapters being used to make the placement of the wheel and tire package in the vehicle envelope end up in the right place, or to adapt a different bolt pattern to the bolt pattern of a vehicle,” Rogers says. “They’re not naturally meant to go together.”
But a consumer might think changing from an eight-lug pattern to a six-lug is no big deal. But the correct fit is key. Tire Rack notes on its website there are 17 different four-to-five-lug bolt patterns, as well as six-to-eight lug patterns for light truck and sport utility vehicles alone.
“As a general rule, those adapters are not well engineered devices. It should be a natural fit.
“There are very few vehicles in the world from the factory that have properly engineered wheel spacers. Porsche is common to do that. But those are very rare, very few, high end vehicles,” Rogers says. “No normal, everyday car will come from the factory with a spacer behind the factory wheel.”
The problem with spacers is that they reduce how much engagement, or how many turns of the lug nut onto the stud, there are. Sufficient engagement spreads the clamping force and gripping load, Rogers says. Maintaining the original equipment manufacturer’s number of turns of lug engagement on the stud is important.
“If the lug nut is hanging on by its fingernails, it’s not going to hang on very long. If it can get a good grip it will hang on a long time, so if you don’t get a sufficient number of turns for the type of hardware onto the stud in the long run it can very well become a problem,” Rogers says.
“When I put a spacer behind the wheel...I start trimming the margins of what’s good versus what’s minimal. It’s just not a good fit.”
Just as OEMs dictate load capacities for tires, they do the same for wheels. At the same time, the manufacturers may use the same bolt pattern on passenger cars that they do on a line of SUVs. The vehicles’ load requirements on the wheels are vastly different.
“You see car wheels in a truck or SUV application that don’t have proper load capacity for the application. It’s a failure waiting to happen,” Rogers says. “Shops need to be aware of that. It’s not just the bolt pattern and the centerbore and the width and the offset and the clearance around the brakes, it’s the load capacity.
“It’s like a tire. Carrying the load is the number one job. If you can’t do that, nothing else matters.” ■
Following the evolution of wheel finishes
There may be only one thing more explosive in the industry than the proliferation of tire sizes – and that’s the evolution of wheel finishes.
Not every tire dealer needs to cover the whole spread of offerings, such as the differences between bright silver paint, silver painted, and bright satin silver paint wheels, or black painted, flat black painted and machined wheels with a black accent.
But Tire Rack Inc. goes “all in” with wheels, and has more than 20,000 active SKUs – more than double the number of active SKUs for the 20 brands of tires it sells. The wheel inventory, which is centralized at the company’s headquarters and then distributed to its six other warehouses as needed, includes upwards of 100 codes for different wheel finishes.
Winter tire and wheel packages
Even though Matt Edmonds, vice president of Tire Rack Inc., refers to wheel sales as “the icing on the cake” for the industry’s largest online tire seller, that icing becomes even sweeter this time of year as winter approaches.
Modern Tire Dealer recently took a tour of the tire dealer’s South Bend, Ind., headquarters as it was ramping up for the season. There are four mounting and balancing production lines set up inside the warehouse, and by the time the tire industry converges on Las Vegas, Nev., for the Specialty Equipment Market Association (SEMA) Show, Tire Rack’s winter tire and wheel assembly team will be running at “full tilt,” Edmonds says. “They’ll do 1,600 tire and wheel assemblies a day out here.” Another team inside the company’s Delaware distribution center will do about the same number.
And while steel wheels used to be the norm in these package deals, Product Information Specialist Woody Rogers says alloy wheels aren’t as cost prohibitive as they once were. The difference in price might be $20 to $30 per wheel, and “it looks more like their summer package, their factory package, and that’s a real benefit to consumers.”