Way back in a different time and place I was first acquainted with Kevlar in the form of a bullet resistant vest to be worn in dangerous places, which as a journalist in Africa I sometimes encountered.
Developed by Du Pont chemicals in 1965 Kevlar is the registered trademark for a high strength synthetic fibre claimed to be five times stronger than steel on an equal weight basis.
Ironically for the theme of this feature, it was first commercially used in the early 1970s as a replacement for steel in car racing tyres, but these days it’s used in all sorts of composite materials and applications from F1 bodies (in conjunction with carbon fibre), brake pads, bicycle tyres and racing sails to body armour and even light “bullet proofing” for executive cars.
Why am I writing this? Because the new buzz word in 4WD tyres is Kevlar, and a number of tyre makers are shouting about using Kevlar in their new products.

NEW WRANGLERS
For instance Goodyear has replaced the Wrangler MT/R with the new Wrangler MT/R Kevlar.
One of the most visible differences with the new Wrangler MT/R Kevlar is its aggressive asymmetric tread design, which has something the company calls “advanced mud-flow geometry”, said to offer exceptional off-road traction.
Additionally, staggered sidewall shoulder blocks are said to help provide continuous biting edges as the tyre turns through thick mud, while the “wraparound” tread features enhanced sidewall traction in mud, sand and rocks.
Special tread guards in the shoulder voids help resist penetration from stones.
This is especially important when tyre pressures are reduced to improve traction off-road, making the sidewalls more vulnerable to punctures.
However the new Wranglers feature sidewall reinforcement with Kevlar and three-ply construction, and are said to be 35 percent more resistant to sidewall cuts and punctures.
 The new tyres also offer tuned rim locking which prevents wheel-tyre movement and minimises the requirement for ongoing balancing, while a lower sidewall rim protector offers wheel protection from damage.
In addition the asymmetric tread pattern has a wide centre rib tuned for highway surfaces and reduced road noise.
Says Pete Ritchie, specialist 4WD trainer from Natural Instincts: “The Wrangler MTR/Kevlar is the quietest mud tyre I have ever run.
“Apart from the incredibly aggressive tread they provide great grip on wet roads, even when towing heavy loads. At this stage they have been better in every sense than any other mud tyre I have run, period”.
The Wrangler MT/R Kevlar is available throughout New Zealand in 21 sizes ranging from 15 inch through to 20 inch wheel sizes.

HANKOOK
Another well-known personality shouting the praises of a tyre is TV personality Bill Hohepa.
As well as his fishing programme on Cue TV (Sky channel 110 or Freeview channel 23), Bill and his wife Linda organise an annual trek around the North Island for two weeks in January, and for this trip Bill fitted a set of Hankook RT03 mud tyres supplied by South Auckland’s Drury Tires to his Nissan Safari
[Insert Hankook tyre and caption OR Bill Hopeha pic here]
This is Hankook's newest and most aggressive tyre to enter the off-road industry, and the new tread design reflects proven tread features of tyres from the past.
At first glance it could be mistaken for the old Goodyear MTs, but upon further inspection, you'll notice that the tread blocks are more V-shaped and are tapered for better grip in mud and snow.
Between each lug Hankook has placed "ejectors" in the tread grooves to prevent stones from penetrating, while a bold shoulder tread helps ward off potential damage in the sidewall.
“The tyres were excellent – beyond excellent, in fact,” Bill told us. “These are the only tyres I fit on my lead vehicle for the trek. While everybody is falling by the wayside these tyres keep going through mud, sand and even that sticky clay we find around New Zealand.
“We even fitted a set to our mechanic’s Navara and he absolutely raved about them,” said Bill.
A TV series featuring Bill’s 2010 Supercharge Batteries 4x4 Trek will be shown on Monday’s beginning March 22 at 8 pm on Cue TV.

GT RADIAL
We’ve got a set of GT Radial mud tyres on our Jeep Cherokee project vehicle, and so far they have proved extremely capable in muddy conditions, including a recent trip to the South Island for the Reefton Jeep Challenge (see December 2009 issue) , and more recently to the Urewera Safari in the Napier area.
But somebody else who swears by the company’s products is champion off-road racer, Bryan Chang, who has been sponsored by the brand for five years. 
“I’ve used a variety of different tyres throughout my career, but none come close to GT Radial,” said Bryan.
“The tyres offer an unbelievable level of grip, so much so that I’m able to run a 2WD set up compared with many other competitors who are forced to run 4WD.
“The weight savings are considerable and allow me to go faster for longer.  This is solely due to the tyre’s ability to deliver superior grip through all conditions.”
There are two key tread patterns available in the GT Radial 4WD range and both are constructed with chip resistant compounds, which enhance their durability and performance. 
The Savero is available as All-Terrain, All-Terrain Plus, Highway Terrain Plus and Mud-Terrain. 
The Mud-Terrain option is a long-life 4WD tyre with outstanding traction in mud and boasts wide lug angle grooves for self-cleaning. 
The Adventuro is available in All-Terrain, All-Terrain II and Mud-Terrain, with a more aggressive pattern - regarded as the pinnacle of the GT Radial off-road range. 
This specific tyre features an extra deep and wide tread which provides exceptional off-road traction and has a specially developed tread and sidewall compound to give a longer tread life.  The heavy duty body plies provide extra protection against punctures and impacts.
Another outstanding feature of GT Radial tyres is the free “Drive 5IVE” tyre replacement guarantee, available exclusively for GT Radial car, 4WD and light truck/ van tyres.
The tyre replacement guarantee covers any manufacturing defect over the first full life of the tyre, up to a maximum of five years from date of manufacture.
Send us your 4WD pictures and stand a chance to win a set of GT Radial tyres.

KUMHO
However, accolades come from all directions, and the Kumho Road Venture MT KL71 was the joint winner of British 4x4 Magazine’s “ultimate tyre test” to establish the best mud-terrain tyre on the UK market.
Eight makes of 235/85 R16 tyres were subjected to six challenging, real-world tests – a mud climb, bog run, side slope, rock crawl, gravel and tarmac braking. One vehicle was involved – a 2007 Land Rover Defender 110.
The magazine found the Kumho Road Venture  KL71 radically different in appearance from all its competitors and said it was best looking as well as the joint best performer. The Kumho was awarded top marks on the rock crawl and gravel braking tests and performed with credit on the mud climb and bog run.
Available from Blairs Supertyre Distributors, the MT KL71 features a cut and chip resistant compound moulded into a directional tread pattern comprised of tightly packed centre tread blocks with stepped edges for improved on-road handling and noise control.
There are also high void, two stage shoulder lugs alternating with ejector bars deep in the voids for self-cleaning suction release, and aggressive sidewall lugs that wrap around and provide the side traction that will aid in deep mud and snow as well as provide sideway traction in ruts. 
The tyre's structure includes twin steel belts reinforced by spirally wrapped nylon to enhance high-speed stability and durability while the two polyester cord sidewall plies promote durability.  
Additional features include siped outer lugs for improved traction in wet conditions and snow.  
Other Kumho tyres include the Road Venture AT KL78 , an all terrain tyre designed to combine on-road driving manners with off-road driving ability. 
It has large, independent tread blocks for directional stability, steering response and off-road traction while full depth circumferential zigzag grooves along with multiple lateral grooves evacuate water to resist hydroplaning and enhance traction on wet roads.
Last but not least the Road Venture APT KL51 is a highway tyre which can also [perform well in light snow.
Kumho says the tyre is designed to provide a comfortable ride, enhance driving stability and reduce road noise.

YOKOHAMA
Yokohama is best-known for its road tyres, but the company also produces a range of tyres specifically for 4WDs and SUVs.
The Geolander A/T-S is a great looking tyre is designed to provide the best balance between on-road and off-road performance and uses Yokohama's new silica-enhanced tread compound that combines sculpted shoulder blocks, rounded-edge intermediate blocks, and staggered centre blocks to blend on-road traction with off-road control.
Unwanted tyre noise can increase significantly when the tyre wears unevenly. The Geolandar A/T-S features rounded-edge intermediate blocks that have 3D pyramid-like zigzag sipes.
This configuration helps reduce uneven wear as extra rigidity reduces block deformation under stress. These blocks are then arranged in a five pitch variation theme to reduce tyre noise to an absolute minimum.
The patented "multi-step" grooves between the tread blocks help clear mud and dirt to increase the tyre’s biting edges for enhanced traction on loose off-road surfaces.
[Insert Yokohama caption and pic here]
And the Geolander MT+ tyre, born from off-road racing, best suits the serious off-road enthusiast– from dunes to rive rbeds, rocky terrain to mud.
The directional tread pattern features large tread blocks that extend beyond the sidewall to provide extra traction and side wall protection. This pattern efficiently removes water and mud from the contact patch while stepped block edges assist in removing mud and dirt from between the blocks.

4WDBITS
If you’re not sure exactly which tyres to choose, or want to have a look at what’s available without moving from your computer, you could do worse than go to 4WDBits.co.nz, New Zealand’s leading on-line retailer of affordable quality 4WD parts and accessories.
“Tyres are one of the most important choices to be made for any vehicle,” says the company.
“A large number of factors need to be considered when choosing tyres.
“Tread pattern will determine how the tyre behaves on various terrains, hard, soft, clay, sand, tar seal, wet or dry. Tyres larger than original may require a low volume certificate, may cause rubbing on ‘guards, chassis or suspension components and may not match the existing rims.
“Tyre size on some vehicles has to be within programmed parameters for the computers and electronics, and fitting tyres outside programmed parameters can lead to stability programmes, traction systems, trailer stability systems and similar systems to come into action at unexpected times.”
4WDbits has a huge variety of brands encompassing most reputable tyres available in New Zealand - Maxxis, Goodyear, Dunlop, Michellin, Bridgestone/Firestone, Pirelli, BF Goodrich, Kumho, GT Radial, Continental, Nankang, Silverstone, Sime/Simex, Super Swamper.
In addition there’s a variety of steel and alloy 4WD rims in 15 x 8, 15 x 10, 16 x 8 and 16 x 10 sizes catering for road and competition 4WD vehicles.
4WDbits also has tyre and wheel accessories including tubes, road legal bead lock rims, compressors, deflators and a Nitrogen filling service.
In addition the website has plenty of information, many links to manufacturers’ web sites and a broad range of accessories.