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New Parnelli Jones Dirt Grip Tires

Side View
The 4-Wheel & Off-Road Staff | Photographer
Posted May 1, 2001

We Try to Test the Tread Off

Step By Step

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  • Click on the filmstrip icon below for a peek at our testing!

  • Wet rocks and steep inclines are usually a bad combo, especially if you need to back up. We blew the proper line starting down this waterfall and had to back up for another shot at the line (or rollover and die), so we tried it before the winch cable came out. To our pleasant surprise we chugged backwards up the boulder and maneuvered into position.

  • Letting the air down to 5 psi for Sledgehammer produced the tire pook we wanted, and the traction coefficient soared. The many sipes on the tread seemed to grip the rocks like glue, and the sidewalls flexed conformably over the boulders. We tried to puncture the sidewalls on some sharpies, but to date it just hasn’t happened. We’ll update you on these tires in a future issue.

  • Sand-running shot roosters high, and the wide 14.4 section width flung the granules. Unlike many ultra-aggressive treads, the Dirt Grips didn’t dig to China, but instead float over the ruts as they scoured the dunes. Even on side hills the wide footprint gave good lateral stability and a sense of safety.

  • We had to wait for good mud in our area, but it was worth it. In both soupy slop and chunky goo the Dirt Grips churned and burned through the oozing earth. A little spin of the tires shot goobers of glop all over us, indicating a good self-cleaning ability.

  • Finding decent test snow in Southern California isn’t easy, so we trundled up Surprise Canyon to Panamint City in February (yes, it’s the winch trip) for virgin white stuff. Again, we were really impressed in wet snow and powder, as these tires kept gripping, digging, and flinging. Who says the PJ initials aren’t a good tread pattern?

When we first heard about the new Parnelli Jones Dirt Grip tire, we knew the name and history of the man, but didn’t have a clue about the tire. Yeah, Jones raced Baja 30 years ago, but off-road tires? We read the specs and decided to try them out, as they had sizes listed from 31 to 38 inches tall. According to the poop sheet, the tread and sidewall have a special cooler-running compound, and at our lower tire pressures that could be a benefit. Also, 16 and 16.5 inches have a 10-ply rating on the sidewalls, another good feature for toughness. And for street users, these radial tires are factory balanced and checked for roundness before shipping. They say the average tire only takes around 5 ounces to balance.

With info in hand and a test schedule set, a quick call to National Tire & Wheel yielded a set of 36x14.50-15 Dirt Grips on 10-inch Eaton steel wheels, already mounted and balanced with minimal weights. We figured the 36s would fit our test mule since 35-inch Boggers did, but these PJs measure a full 36 inches and then some, causing a bit of sheetmetal reformation. We ended up trying them on a couple of different rigs in different places for a more rounded test, rather than a quick check on a test track like some other mags. That also meant we had to wait for rain, find some snow, and (gasp) try ’em on the street. Since mileage figures can’t be told for quite some time, we’ll give you an update in a later issue.

The tread design is unique. It’s a bunch of PJ initials and three different lug patterns on the edges. Tester and Jp Editor John Cappa cracked that there was no way the initials PJ could be the ultimate tread design, and we admit we had our reservations too. But after blasting through the sand and tearing up the rocks, slopping through mud and snow, we were all impressed. These tires are called Dirt Grip, and it is an appropriate name. We called ’em Mud Grip, Sand Grip, Snow Grip, and Street Grip, because at the appropriate pressure for the vehicle and terrain, they do what it says—grip. If you want to see these donuts in action, check out our Web site at for a behind-the-scenes video of the test, just like you were there yourself.


National Tire & Wheel
Wheeling, WV