2013 30-Inch UTV Tire Shootout: Five Tires Tested

Editor’s note: This tire comparison was conducted in December 2012, when a 30-inch tire was about as large as the UTV-specific market offered. The five tires tested here represented nearly all of the serious choices available for high-speed desert driving and rock crawling. The test also helped us select tires for the 2013 King of the Hammers UTV race, where this same Polaris RZR XP finished second.

At the 2012 Sand Sports Super Show, I found five new 30x10R14 tires from four manufacturers. Today, 30-inch tires are relatively modest, but in 2012 they were at the leading edge of UTV tire development.

Before these tires arrived, moving to a substantially larger tire often meant mounting a light-truck tire on a 15-inch wheel. I had run 30×9.50R15 BFGoodrich KM2s and 31×11.50R15 Pit Bull Growler LTs on several vehicles. They were extremely tough and their added height made rock crawling easier, but they came with major compromises.

A BFG KM2 alone weighed approximately 42 pounds, while the complete tire-and-wheel assembly approached 60 pounds. That much rotating and unsprung weight affected acceleration, clutching and suspension performance. The stiff sidewalls also produced less predictable breakaway traction in fast desert corners.

The five tires in this comparison were different. Each was designed specifically for a UTV, mounted on a 14-inch wheel and carried a load rating more appropriate for a side-by-side. At the time, they represented some of the first realistic ways to combine 30-inch ground clearance with UTV-friendly weight and handling.

Why We Conducted the Test

Our primary objective was to identify the best tire for three distinct environments:

• High-speed desert terrain
• Hard-packed short-course terrain
• Technical rock crawling

There was also a racing objective. We were preparing this same 2013 Polaris RZR XP for the 2013 King of the Hammers UTV race. The event combined high-speed desert sections with severe rock trails, making tire durability, ground clearance and predictable handling critical.

We ultimately raced the RZR to a second-place finish at the 2013 King of the Hammers. That result gave this comparison a purpose beyond simply ranking five tires: it helped guide a real race-tire decision for one of the most demanding UTV events in the country.

How We Tested the 30-Inch UTV Tires

After contacting the manufacturers, we gathered sets of all five tires and began testing in early December 2012. Every tire was installed on our 2013 Polaris RZR XP and evaluated in desert, short-course and rock-crawling conditions.

Ideally, all five tires would have been mounted on identical wheels. That was not financially practical, so readers should account for minor wheel-weight and offset differences when reviewing the results.

Before driving, we weighed and measured each mounted tire.

30x10R14 Tire Specifications

The measurements revealed meaningful differences despite every tire carrying the same nominal 30x10R14 size. The Maxxis, ITP UltraCross and ITP BajaCross measured closer to 29 inches. The GBC was slightly taller than 30 inches, while the STI measured a full 31 inches and weighed nine pounds more than the Maxxis.

Desert Tire Test

For the desert test, I traveled to Barstow, California, and met Rick “Wally” Wallace of Side x Side Outfitterz and Mike Lasher of SxSPerformance.com. Both had extensive experience driving and racing UTVs in the desert.

We tested the tires across high-speed dirt, sand washes, whoops and g-outs. Tire pressure was set at 12 psi for every set.

Desert rankings

1. GBC Kanati Mongrel
2. ITP BajaCross
3. ITP UltraCross
4. Maxxis Bighorn
5. STI Roctane XD

The Kanati Mongrel delivered the best overall combination of weight, size, stability and desert traction. The STI’s extra height helped with clearance, but its 39-pound weight and stiff construction noticeably affected steering and suspension response at speed.

Hard-Pack Short-Course Test

For the short-course and rock-crawling portions, I met Paul Hart at Prairie City State Vehicular Recreation Area in Northern California. Prairie City hosted Valley Off Road Racing Association short-course races and Nor Cal Rock Racing events, giving us both types of terrain in one location.

The short-course test included high-speed cornering, jumps and g-outs. All tires were tested at 9 psi.

Hard-pack short-course rankings

1. Maxxis Bighorn
2. GBC Kanati Mongrel
3. ITP BajaCross
4. ITP UltraCross
5. STI Roctane XD

The light, flexible Bighorn produced a plush ride and predictable handling. Its lower weight helped the RZR accelerate and allowed the suspension to react more effectively over jumps and rough sections.

Rock-Crawling Tire Test

Ground clearance, sidewall construction and traction became more important in the rocks. We again set every tire to 9 psi.

Rock-crawling rankings

1. STI Roctane XD
2. GBC Kanati Mongrel
3. Maxxis Bighorn
4. ITP UltraCross
5. ITP BajaCross

The STI was the heaviest tire in the test, but its true 31-inch mounted height, durable carcass and strong rock traction worked in its favor here. Its additional clearance helped the RZR negotiate obstacles that placed the shorter tires closer to the rocks.

Overall 30-Inch UTV Tire Rankings

After combining the three terrain evaluations, Wally, Mike, Paul and I ranked the five tires for overall versatility.

1. GBC Kanati Mongrel
2. ITP BajaCross
3. Maxxis Bighorn
4. STI Roctane XD
5. ITP UltraCross

The GBC Kanati Mongrel won because it performed near the top in every environment. It ranked first in the desert and second in both the hard-pack and rock-crawling tests. No other tire combined that level of versatility with a true 30-inch mounted height and relatively manageable weight.

Maxxis Bighorn

The Maxxis Bighorn felt familiar and predictable. One tester described it as feeling “like home,” which accurately summarized its behavior.

Its flexible radial carcass delivered the plushest ride and strong traction. At 30 pounds, it was the lightest tire tested, helping performance in the desert and on the short course. It was also the only 6-ply-rated tire in the group, which created some concern about durability in severe racing conditions.

The Bighorn measured only 29 1/8 inches tall and tied the Roctane as the widest tire at 10 inches. We would have preferred a narrower version for the front axle.

GBC Kanati Mongrel

The Kanati Mongrel was an 8-ply-rated radial and the only DOT-marked 30-inch tire in our original comparison. Its rounded profile, siping and substantial rim guard made it a well-rounded design.

It ranked first in the desert and second in the short-course and rock tests. At 33.3 pounds, it was the lightest of the 8-ply tires. Its 30 1/8-inch mounted height and 9 3/8-inch width also produced what we considered the most proportional shape.

The only notable handling criticism came on hard-packed corners. Its breakaway was not quite as predictable as the Bighorn or Roctane, although it remained manageable.

ITP BajaCross

The ITP BajaCross ranked second overall and performed well across all three environments. Its tread delivered predictable behavior in the desert and on the short course, while its durable construction already had a strong reputation.

It was the only directional tire in the comparison. That could complicate spare-tire placement if the spare needed to be installed on the opposite side, although we once ran one in the reverse direction without noticing a substantial difference.

Its 29 1/4-inch mounted height reduced its ground-clearance advantage in the rocks.

ITP UltraCross

The UltraCross resembled an all-terrain light-truck tire but was not DOT marked. Its closely spaced tread was designed to reduce rolling resistance and road noise while limiting the open spaces where sharp rocks and other debris could reach the carcass.

Its shape and dimensions were similar to the BajaCross, but our testers felt it produced less traction when cornering in the desert and on the short course.

STI Roctane XD

The STI Roctane XD was clearly the largest and most heavily constructed tire in the test. It measured 31 inches tall, 10 inches wide and weighed 39 pounds.

Its height, stiff sidewall and strong traction made it our favorite in the rocks. Those same attributes worked against it in the desert, where the extra rotating and unsprung weight affected acceleration, steering and suspension response.

For a rock-focused UTV in 2012, however, the Roctane XD was difficult to beat.

Fitting 30-Inch Tires on a Polaris RZR XP

Installing a 30-inch tire on the original RZR XP required some front-fender work. We retained the factory flare but moved its rear section backward and trimmed the plastic underneath. A self-tapping screw secured the flare to the chassis tube behind it, providing enough clearance in most situations.

The only contact we experienced occurred when landing a jump on the short course with the extra-tall STI Roctane XDs.

Clutch calibration

A 30-inch tire noticeably changed the RZR XP’s performance. The additional diameter and weight pulled engine speed away from its ideal powerband. We installed an EPI Performance clutch kit with revised weights and springs, which made a substantial improvement.

How the Test Car Performed at King of the Hammers

This comparison was about more than choosing a recreational tire. The desert testing showed how each tire handled speed, whoops and sand washes, while the Prairie City test exposed the tires to hard-packed corners and rocks. That combination closely matched the conflicting demands we expected at King of the Hammers.

We raced this Polaris RZR XP in the 2013 King of the Hammers UTV race and finished second. At a time when 30-inch UTV tires were still considered unusually large, the result demonstrated how quickly purpose-built UTV tires were closing the gap between desert speed and rock-crawling durability.

Later 30-Inch UTV Tire Additions

The following tires were added to the article after the original December 2012 comparison. They were not included in the back-to-back test or its rankings.

GMZ Kahuna

The GMZ Kahuna was an all-terrain, DOT-marked tire with an 8-ply-rated radial carcass. It was offered in 30x10R14 and 30x10R15 sizes, with the 14-inch version listed at approximately 32.75 pounds.

Moto Race Tire Crawler

The Moto Race Tire Crawler X ROX DD combined a rock-oriented tread compound with an 8-ply-rated, DOT-compliant construction and Kevlar reinforcement.

STI Chicane RX

The STI Chicane RX used a non-directional split-knob tread and an 8-ply-rated carcass intended to balance durability, weight, flexibility and road manners.

Sedona Rock-A-Billy

The Sedona Rock-A-Billy featured an 8-ply-rated radial carcass, aggressive shoulder lugs, integrated rock ejectors and a built-in rim guard. Its design targeted mixed rocks, hardpack and trail riding.

GMZ Ivan “Ironman” Stewart Edition

The GMZ Ivan “Ironman” Stewart Edition used an 8-ply-rated DOT radial construction with shoulder lugs extending down the sidewall for additional soft-terrain traction and protection from rocks.

Final Verdict

The GBC Kanati Mongrel was the best all-around 30-inch UTV tire in our 2012 test. It combined a true 30-inch mounted height with manageable weight and consistently strong performance in the desert, on hardpack and in the rocks.

The Maxxis Bighorn was the best choice for drivers prioritizing light weight, ride quality and predictable hard-pack handling. The STI Roctane XD was the standout for dedicated rock crawling, while the ITP BajaCross delivered a durable and balanced second-place overall performance.

More importantly, the comparison captures a turning point in UTV development. In 2012, a 30-inch tire was still considered extreme and the market offered only a handful of suitable choices. Within a few years, that size would become commonplace as UTV power, suspension travel and factory tire clearance rapidly increased.