Back to top

M/Ts versus A/Ts and which should you buy?

24 November 2015

Why do you want M/T tyres? It’s not something many people like to admit, but in most cases, M/Ts are fitted for fashion, rather than function.

Of course, there’s nothing wrong with this decision (everyone to their own), but a problem often arises when users don’t know what they are getting themselves into. Generally speaking, the problems (read: complaints) start with noise.

Although some tyre brands may be marginally quieter than others, on the whole, M/Ts are noisy. It’s the price you pay for that extra off-road traction.

The noise generated from an M/T tyre has different origins. The larger lugs (and greater voids) are not as seamless when they contact the road and surprisingly, the tyres also generate considerable wind noise, much like a fan.

In most cases, the more aggressive the tread design, the more noise the tyre will make. So, if you’re worried about your vehicle’s NVH levels, forget the M/Ts and stick with a modern A/T tread design.

Where there’s noise, there’s often vibration, too. This doesn’t necessarily mean that an M/T tyre will cause bolts to fall off your vehicle, but you can expect a slight resonance to be transferred through your 4×4’s steering system. Again, if the thought of this bothers you, do not fit M/Ts.

There’s no hard and fast rule, but as far as percentages go, most A/T tread designs are 70% biased towards on-road use. The other 30% is reserved for off-road. In the case of mud-terrains, the ratio swings the other way — usually 80% off-road, and 20% on.

The exception to this generalisation is Cooper Tyre’s new S/T Maxx, a thoroughbred all-terrain which offers a very close 60/40 split, erring on the off-road side. It’s what you would call a niche tyre as there aren’t many tread patterns out there that are similarly designed. Nonetheless, any tyre that’s off-road focused will not match the tar-driving performance (handling and safety) of a well-designed A/T.

To be clear, most handling and safety compromises will be felt on wet tar. General day-to-day driving (braking and cornering) will not be drastically affected by fitting M/Ts. However, regardless of how wet or dry the road surface may be, an M/T tyre is not designed for high-speed cornering and braking. Not only will the tyre underperform compared to an A/T or H/T tyre but the tread itself may suffer irreparable damage in the way of cuts, chips and tearing of the lugs.

This raises the subject of durability. One of the strongest arguments for wanting to fit a set of M/Ts is for the added durability they provide off-road. The secret to their durability lies in their carcass construction, and the fact that they are usually made with thicker sidewalls, more rubber, and a tougher compound. The downside to this increase in durability is their weight and flexibility.

The stronger a tyre, the more rigid it will be, and the less comfortably it will ride. Weight, on the other hand, adds to fuel consumption. Added wind resistance (of the tread pattern) also plays a minor role.

At this stage, with so many negative features piling up against the fitment of M/Ts, you may be wondering why anyone would consider the move. While it may be true that A/Ts are the more logical, day-to-day option, you’d need only experience the incredible traction-advantage of an M/T to know why so many off-road enthusiasts make the change.

What’s more, for many 4×4 owners, the fitment of M/Ts is a declaration — a statement to other road-users that says, “I drive off-road”. In other words, it’s the less tactless equivalent of spray-on mud!

But regardless of your reasons for wanting to go the M/T route, the important thing to remember is that there is no such thing as a quiet, comfortable, wet-tar performing mud-terrain. No matter what the brochure says, M/Ts will affect the way your 4×4 drives on a daily basis.

So, if you suspect that you may be a high-maintenance vehicle owner — one that’s acutely aware of any new knock, noise or vibration the car may make — it would probably be best to steer clear of the M/T route.