|Author: Scott Wilson February 2001||
The Dunlop Tire Company is the ancestor of the first company to produce a pneumatic tire. Dunlop Tire is currently one of the leading tire manufacturers, and their tires are found on many vehicles as OEM equipment, including models made by Mercedes-Benz. Their line-up of tires ranges from low profile, Z-rated sports car tires to large, knobby-treaded light-truck tires.
The Dunlop Radial Mud Rover is the most aggressive tire that Dunlop manufactures for light-trucks. It is available in sizes ranging from 27x8.50R14 up to 35x12.5R15. We put this 35x12.5" size to the test on one of our 4x4Wire project vehicles, a solid axle 1988 Toyota 4Runner.
We had an experienced local tire shop that carries the Dunlop brand handle the mounting and balancing of our Dunlop Mud Rovers. The installation went smoothly, and the weight needed for balancing ranged between 2-3 oz. of weights per wheel.
|35x12.5" on an 8" wheel|
Our initial impression of the Mud Rovers was that they had a pleasant ride on the street and highway. The noise level from the 35" meats was acceptable, actually lower than expected for a 35" tire. As more and more miles were put on the tires the noise level did increase some, but it remained better than an average 35" mud tire.
Dry traction is not an attribute most customers seek in a mud terrain tire, but the Mud Rovers have good dry traction. In an evasive maneuver to avoid a collision on the freeway, the tires gripped predictably, and did not break traction with the pavement in the extremely hard braking that followed. The tires also gripped well on windy mountain roads, and in the turns the nearly 10" tall sidewalls rolled an acceptable amount.
When the rainy season came we were quite impressed with the wet traction capability of the Mud Rover. The tires allowed us to make hard stops without wondering if we were going to lose traction. The large tread spacing dispersed water from under its footprint with ease, keeping the rubber against the road.
After a few thousand miles on the Mud Rovers, we started to experience vibration from the tires at freeway speeds. We brought the tires back in for balancing, and they took from 2-6 oz. of weight to balance, a noticeable increase in balancing weight since the original balancing. The balancing took away some of the vibration, but not all of it. We continued to have vibration issues, and eventually traced this to out-of-round tires. We inspected the steel wheels; they were true. The two worst tires were a quarter of an inch out of round. Dunlop told us that this was very unusual, apologized for the inconvenience, and immediately shipped replacement tires right out.
While waiting for delivery of the new tires, we purchased new alloy wheels. The purchase was unrelated to the tire review, but it was convenient -- we knew that these new alloy wheels were true. We also removed and inspected the rear axles on the 4Runner. One of the axle shafts was beyond factory-acceptable specification, so we replaced it.
When the new tires arrived we immediately mounted them on the new alloy wheels. The tires were all perfectly round, and took 2-3 oz. of balance weight. We put another few thousand miles on the new wheels and tires before vibrations began to reappear. We rebalanced the tires: they took several ounces of weight to balance and one tire was an eighth of an inch out of round -- but the balancing cured the vibrations. We kept visiting the tire shop for balancing every few months, with intermediate visits after loosing weights while four-wheeling. Thank goodness we paid for that lifetime balancing!
We also noticed that when the 4Runner was loaded down for week-long 4wheeling trips that the tire vibration nearly disappeared. Because of this we feel the Mud Rovers would possibly perform better on a full size (heavier) truck. Another item of interest is that the Mud Rovers would flat spot if parked overnight during cold weather. For the first few miles of driving the following morning you could feel the thump-thump-thump of the flat spot on the tire. This would go away as the tires warmed up.
|At 12 PSI|
We were very pleased with the Dunlop Mud Rovers in off-highway use. We tested the tires on rock, dirt, mud, and sand -- they performed beautifully in all conditions. We even took them over the Rubicon trail in the Sierra Mountains three times, over trails in the Shasta Mountains and San Bernadino Mountains, and over trails in Stoddard Valley and Johnson Valley in the desert.
|Climbing on Tank Trap|
The side lugs on the Mud Rovers have a staggered edge which essentially opens up the pattern even more at the edge of the tread. This is a nice feature and helped a lot with getting the vehicle to go where we pointed it in tough situations, like climbing out of slippery ruts.
The open lug pattern provided excellent self-cleaning capability in mud. The center tread lugs are staggered, and provided good side-hill stability. The only situation where we felt the Mud Rovers lacked was in climbing smooth rock faces... but then again, rock crawlers expect their tires to perform like theyre made of incredibly sticky glue.
|On Tank Trap|
We found that the sidewalls on the Mud Rovers were VERY pliable. Because of this, we usually ran a few more PSI than normal in each tire to retain a little more tire height while aired down for wheeling. A pliable sidewall usually translates to a thin, easy to tear sidewall... but not on these tires. While the Mud Rover sidewall doesnt compare to a massive bias-ply tire, I wouldnt call it thin either. The sidewalls on the Mud Rovers handled rock scrapes like a champ, and we never once had a sidewall tear on us.
|On the Rubicon Trail|
The Mud Rovers are a good tire. The tires worked out wonderfully off-highway and the times we were wishing they offered a little more traction were few and far between. For on-road driving we think the tires may be better suited for a heavier, full size vehicle or a vehicle that sees less street miles than our test vehicle did.