Skip to main content
Blog

by Matt Konkle
Torque Editor-in-Chief


The vast Mojave Desert isn’t just claimed by Jeep vehicles during this year’s King of the Hammers event. There is everything from utility terrain vehicles to fully-loaded Jeeps and trucks taking on everything the desert, and surrounding rocky enclaves, can offer.

But when you look at each race during the week, you’ll see designations on vehicles that may seem strange unless you are fully indoctrinated in the Ultra4 Racing world.

So, for those who do not know, and are planning to follow along for KOTH week, here are some of the class differences you’ll need to understand.

4400: Unlimited Class

This is the original unlimited class that started the King of The Hammers years ago, and each vehicle is heavily modified and engineered to compete during the main King of The Hammers race. Drivers have to earn a spot to compete in King of The Hammers and their rides are not limited on tire size, engine or chassis design, other than to meet the safety requirements for the class. They also must have a transfer case, four-wheel-drive system and can utilize either a straight axle or independent front suspension.

4500: Modified Class

This class has been racing in ULTRA4 since 2012 and is one of the three classes that can compete during the Every Man Challenge. Currently, these do not have to qualify to race in the EMC race during KOTH week. This class is marked by vehicles that have a modified OEM Chassis or OEM Style Chassis, 2 -2.5 inch diameter shocks per corner, mechanical steering and 37-inch United States Department of Transportation approved tires.

4600: Stock Class

This class has also been racing in ULTRA4 since 2012 and is one of the classes eligible to take part in the Every Man Challenge during KOTH week. Currently, these vehicles do not have to qualify to race in the EMC. This class is marked by using a stock frame, factory engine and transmission, 35-inch DOT approved tires, 2.5-inch diameter shocks per corner and mechanical steering.

4800: Legends Class — Trophy Class

'

This class has been racing in ULTRA4 since 2014 and is one of the 3 classes eligible to race in the EMC during KOH week. These vehicles do not have to qualify to race in the EMC, and the class itself is one of the fastest-growing in ULTRA4 as older ULTRA4 cars can enter as long as they meet the requirements. Vehicles in this class can only have front-mounted engines, contain two seats side by side, utilize only a single shock per corner, use maximum 37-inch DOT non-sticky tires and only have solid axles installed.

While these classes represent the majority of full-size vehicles, KOTH week also features many UTV and full-size truck classes, including stock, pro modified, open and unlimited.

Top Jeep Articles

  • August 6, 2026
  • 5 min read
Choosing the Right Armor: Full-Width vs. Mid-Width vs. Stubby Bumpers
Don't let factory plastic ruin your next trail run. Break down the key differences between full-width, mid-width, and stubby bumpers to find the ultimate armor for your Jeep build.
READ MORE
  • August 4, 2026
  • 5 min read
Top Reasons To Buy Jeep Alloy Wheels
Whether you just want to make a style change, or your are upgrading tires, changing over to alloy wheels is an excellent upgrade with numerous benefits.
READ MORE
  • July 31, 2026
  • 8 min read
What Are The Differences In Jeep Seat Cover Materials
Seat covers form an excellent shield for your vehicle's existing seats, but they also provide extra comfort, add styling and a dash of customization. However, with so many different choices, how do you know which set is perfect for you?
READ MORE
  • July 30, 2026
  • 4 min read
How To Use A Jeep's Four Wheel Drive
Your vehicle's two-wheel drive system can handle a lot, but not everything you'll face when driving. So knowing all about your vehicle's four-wheel-drive settings, and which is best to use in certain situations, is definitely helpful.
READ MORE
  • July 28, 2026
  • 4 min read
Top Five Jeep Wrangler Alloy Wheels
Our recommendations of top-selling alloy wheels for Jeep Wrangler.
READ MORE
Red Jeep Wrangler with a black soft top against a white background
  • July 27, 2026
  • 5 min read
What Is The Best Material For A Jeep Wrangler Soft Top?
A Jeep soft top isn't just a one-size-fits-all application. And one of the most important things to consider before purchasing is what kind of material makes up that top. Here are some of the most important material differences.
READ MORE
A Jeep Wrangler climbing rocks with a display of tire sizes
  • July 22, 2026
  • 3 min read
Jeep Tire Size Calculator & Comparison Tool
Compare tire sizes, see speedometer changes, and find the right fit for your Jeep.
READ MORE
  • July 20, 2026
  • 3 min read
Jeep Speedometer Gear Tooth Chart & Calculator Guide
Find the exact replacement speedometer gear for your Jeep’s new tire size and gear ratio.
READ MORE