Forget about all those letters and make your life a little easier, next time you're ready to buy new off road tires, just tell the guy "gimme the 35-inch Xterrains" - He'll know what you're talking about.

For being a relative newcomer in the world of off road rubber, Pro Comp has created one of the best all around tires for solid off road traction. From rough desert trails to mud and snow, the new Xterrain grabs and holds on.

The Xterrain vs. Pro Comp's AT What gives the Xterrain holding power? Could it be the large contact patch, which provides a firm foot hold on even the toughest terrain?

Or maybe it's the high voids, giving the Xterrain the ability to dig in to the mud, snow and slush, allowing you to keep moving forward. Perhaps it's the shoulder lugs, staggered and ready to take a bite out of any terrain.

Actually, it's a combination of all three, giving the Xterrain the ability to take you wherever you want to go. The new tread design is a bold step up from Pro Comp's previous AT and Mud Terrain tires. If I didn't know better, I'd think Pro Comp was planning on joining the rock crawling battle field.

Or are they? No one knows for sure what their plan is, but the new Xterrain has the look and feel to take on the toughest, extreme rock crawling obstacles out there. On snow and slush covered highways, the Xterrains kept a solid hold on the pavement, never losing traction.

It must have been the uni-directional tread pattern keeping the tires firmly planted on the ground. There's not a whole of snow in Las Vegas, so the snow I encountered in Southern Utah/Northern Arizona will probably be the last snow these tires ever see.

What we do have in Las Vegas is some of the most brutal dessert terrain you'll ever run across. From washboard roads that lead to nowhere, to jagged edged rocks dotting the canyons and foothills, the Xterrain handled them all...

Close-up of the Xterrain's aggresive tread design Put to the Test On an unseasonably warm Thursday (hey, this is our job - it's what we do), we set out, two Jeeps looking to find a solid test-bed for the Xterrains.

After we aired down the Xterrains to between 15-20 psi, we set out to abuse the sidewalls and find out how they'd stand up to a little punishment. For those who have never experienced the Las Vegas desert, it is nothing but rock.

Everyhwere you go, the terrain is rocky enough to rattle your teeth. Aired down, we we able to get up 35 mph with the tires holding firm, not letting the Jeep slide from side to side and maintaining traction in curves.

Up we went, further into the foothills, away from pavement and past the point of no return for those "street" four wheel drives - you know the ones I'm talking about.

Once we passed that point, we encountered the rough terrain we were looking for, narrow trails with plenty of hazards, which forced us to do a little rock crawling. Sharp edges bit into the rubber, but the aggressive tread of the Xterrains bit back. This terrain put the sidewalls of the Xterrains to the test.

Jagged edged rocks dug into the sidewalls, leaving their mark, but not cutting into the sidewall. The folks at Pro Comp say this new tire has a special 2-ply sidewall made of thick polyester combined with dual sidewall rubber - that must mean extra tough sidewalls.

The staggered tread pattern of the Xterrain helped the off-camber Jeep grab onto the rocks and wouldn't let go.

Complaint Department I do have one complaint about the Xterrains - they are not loud enough on the road. I don't know whose bright idea it was to start making off road tires "quiet" and I don't know anyone who buys off road tires because they're quiet.

It must have been some long-ago, politically-correct desk jockey who spends his weekends driving around L.A. in his 4-wheel drive, yuppy B-Mer with his "fingers on the pulse of America". Describing off road tires as "quiet" is not a good thing - how is a "quiet" tire going to give you the traction you're going to need when you go off road?

"Quiet off road tires" is as oxymoronic as "rolling stop", liquid gas", "seriously funny" and "rap music". Me, I want my tires to make some noise, I want people to know I coming. Loud tires mean aggressive tread and the ability to take on extreme terrain and go just about anywhere I want to.

The Xterrain comes in various combinations of 33", 35" and 37" sizes for 15", 16" and 17" wheels. The warm Las Vegas spring has allowed me to remove the doors from my YJ a little early this year and I can hear the hum of my Xterrains as they grab the pavement, waiting for the next rip off road.