Size Wars: The Debate Over 35-inch vs. 37-inch Tires

May 10, 2013

“You’re My Only Hope”

Whether it’s in-person or online, we’ve heard the distressed cry countless times – an offroader is buying new tires and needs help deciding between 35s and 37s.

Offroaders agonize over which size tires are the best choice for them and they want to get it right before they commit. There’s a lively debate for both truck and Jeep owners and the Size Wars rage on. Budgets often dictate which tires you’ll get, but there are other considerations. Arming yourself with as much knowledge as possible is a good idea before you go to battle-¦

These Are Not the Tires You’re Looking For

“The first question to ask is if you’re going for an actual offroader or a mall crawler that just looks cool,” says Jorge Ponce, 4 Wheel Parts sales associate. (Size) 37s make more sense for rock crawling and hard wheeling, but their sheer size and weight puts more strain, wear and tear on parts. Going with 37s often has a domino effect that leads to upgrading everything, including suspension, engine, steering, brakes and more.

“Nine times out of 10, when you go to a larger tire you need to re-gear and re-calibrate your speedometer,” points out Mark Mathews, Pro Comp USA marketing manager.

Drivers have different comfort levels about what they want to put their vehicle through and how much coin they want to spend.

“The biggest mistake people make when they want bigger tires is they’re not prepared for the entire budget and don’t realize how deep they have to go,” says Jorge.

Jorge notes that when you choose bigger 37-inch tires, the parts most likely to break are axles and drive shafts.

“Advertised tire size can be different than the true size,” he says.

He’s seen his fair share of shoppers who come in and tell him they want the tires their friend has.

“I have to explain there are differences between truck and Jeep makes and one size tire doesn’t fit all. If you’re part of a club, you may be able to borrow and test drive tires first, but otherwise you have to take a long look at your vehicle and budget to decide which tires are best for it.”

“Use the Force”…and Good Sense

Bigger tires and lift kits carry a heftier price tag, and there are other issues to consider. Running 37s will consume a lot of power and negatively impact your mileage. Larger tires also take a greater toll on an automatic shift than a manual. Another factor to weigh in with 37s is how they will make getting up to speed harder and change your braking distance. Taller tires generally reduce braking and stopping your truck or Jeep will take more distance.

“You’re really only gaining an inch of ground clearance when you go from 35-inch to 37-inch tires,” says drivetrain expert Rody Jarve. But he acknowledges that no matter what size you start out with, if you get the bug you’re going to keep upping them.

“I’ve seen guys start out with 32s, go to 35s and then to 37s,” Rody says, noting that 35s have come down quite a bit price-wise and make sense for today’s cost-conscious buyers.

The Big Tire Strikes Back

Buyer’s regret is one of the downsides of going conservative and choosing 35s over 37s. Many argue if you can afford the mods, the optimal way to run 37s is to get a full 6-inch lift with control arms, axle shafts, gears, and other axle components.

“The average new Jeeps can clear 37s with a 4-inch lift,” points out Mathews.

There’s also the assertion that four-door rides look better with 37-inch tires, although it ultimately comes down to personal taste.

“I debated it, but in the end I knew I wanted to go with 37s,” says Brandon Hood, owner of a new Jeep Wrangler JK. “I do a fair amount of offroading and love the way they handle – especially in the desert crawling rocks.”

A taller 37-inch tire gives more clearance and will roll over a boulder that you may get hung up on with 35s.

Debates over size will always go on, but these insights empower offroaders to make their own informed decisions when it’s time to buy new tires.

BIODavid Beran is a copywriter at 4WD. Research provided by CJ Bantam, a freelance writer in the offroad industry.