I did a load of research for 20” AT tyres, all the way up to 305 wide, but they require a little ingenuity..
I was very close to getting some Cooper Zeon LTZ but I have a feeling they have changed to a different type . It depends how heavy off road you are going as to whether you want 18” or 20”.
Also there are different rim widths like 8J 8.5J etc that will accept different widths. Do you just want AT tyres on stock rims or are you looking for a wider tyre or more profile depth?
You need to consider speed rating and speedo error if you change diameter.
Looks like I **** out on the popcorn.
I decided that my Pirelli Scorpions were fine and an engine was more worthy of my time and financial commitment.
I’ll have a dig through my research and post something up.