Thread: 18" v 19" v 20" tyre sticky patch size difference?

Wheels look great kondo 👌

But why show the white writing on the tyres, I would have them turned inwards!

Originally Posted by Lukeis

Wheels look great kondo 👌

But why show the white writing on the tyres, I would have them turned inwards!

Then people would only be able to read them after you ran them over
Andrew

Originally Posted by Bytemrk

Current model D4's come from factory with either 19" or 20" rims.

He is refering to his title.I added 20" and asked some 20" owners to get some measurements too
Andrew

I only have experience with 265/75r16 on the D2 and 255/55r19 GG's on my new D4 and even at low pressures of around 15 psi the tyre as Andrew said does not want to float like the larger 16s (Toyo MT) did they break through the soft sand and plough....with sand moving through the rim... I would happily take pressures even lower on WA's soft sand, I have seen Gordon's posts talking about 12 psi and lower... they are better with momentum but very plough like at slow speed and take offs... problem is as soon as you come to any limestone you have to air up... I am hoping to get 18's soon and most accounts seem to suggest that they help in the soft stuff. Gordon recommended 285/60r18 Zeons or similar for very soft sand use although I like the 647 as well...

Here are my measurements.Cooper AT3,265/60R18,cold.

15psi 290mm
18psi 265mm
20psi 255mm
25psi 235mm
30psi 210mm
37psi 185mm

Pic at 18psi and then 15psi.




After doing this experiment Im much happier with the 18" tyres.20psi should be good on beaches,then there is plenty more deflation available at 15psi.Much more sidewall height than the OEM 19" Wranglers at 15psi.

Andrew

At 18psi there's barely any bulge in the 285 60 18s. So little in fact that i was tempted to just drive home to pump mine up last weekend! Interesting to see how they go with an extra 500kgs of cargo though.

Thanks Andrew. I guess the myth about 18s being so much better on the beach than 19s just got busted based on the contact patch size. I will concede that the 18s will have a wider patch by 10mm though. Probably should have worked out the square meter size to get a true comparison. It will be interesting to see if someone with 20s comes to the party.

I'm sorry I did not do the same measurements with my D2 before I sold it so if someone reading this feels like it - please. The D2 just did the sand so well. Was not a problem stopping & then pulling away on the soft off ramp to the beach at Bribie, Straddie or Rainbow Beach.

Need to wash those wheels Andy. All the brake dust has made them look Grey..