Is a narrow or wide tyre best for a 4×4?
Tyres are always difficult to select because there’s so much choice and offroaders need tyres to perform in a wide variety of terrains. There’s a lot to decide; profile, tread pattern, construction and more…but in this post let’s talk about whether you should go for a narrow or wide tyre of the same diameter.
The received wisdom is of course to choose wide. The logic is generally given that a wider tyre has a greater contact patch (area of tyre touching the ground), and therefore better traction than the equivalent-diameter narrow tyre. I’d also suggest #insta-tuff looks are a factor. And of course, if you look at racing cars they have very wide tyres too. In many things car, the more the better, right? And that includes rubber.
But is this received wisdom right?
Well, you can’t look at circuit racing cars and say well, wide tyres on those cars mean wide tyres on 4x4s are good. Racing cars operate at high speeds so cooling becomes a problem, their terrain is smooth and flat, lateral cornering forces are high, and precision of steering and handling is important. Pretty much the opposite to offroading.
Then again, physicists would say that area = force / pressure, so no matter what the shape; diameter, width, profile – the contact patch would be the same. And they would further say that a lot of pressure (weight) over a small area (contact patch) gives the same friction, or grip, as the same pressure over a wider area. But does that theory play out in practice?
So I decided to take a closer look at the wide vs narrow debate; I read some technical books, talked to a few engineers, drew on my own experience as an offroader, and actually measured a variety of tyres of different widths. And I looked at weights.
The results are in the video where I talk through what I did, the results and come up with some conclusions and recommendations which I hope will help you select the best tyres for your vehicle.
And if you want to know what all those numbers mean, watch this:
And don’t run old tyres!