Morning All!!

As the subject says I'm Confused.com with regards tyres. Apologies for bringing this topic up yet again!! Maybe we could set up a database of what tyres have been fitted to what rims so existing and new member s have a 'quick reference' to what's possible? I'll bring that up in a seperate post though

I've spent several hours searching both this site and other RRS sites to get a definitive answer on what the max size you can fit to a standard Supercharged rim, with a 30mm spacer, and come to no definitive conclusion

What I've found is that the 'widest' tyre fitted is a 305 on a 22" or 23" rim, with an off set of 35mm, with a 30 profile. I've also found that are American friends have successfully fitted a 285.50R20 on standard 20x9.5" rims with or with out a spacer. this equates to a theoretical tyre height/ diameter of 31.25" or 794mm. Cooper quote 31.29 on a 9".

So based on the above if I have 20x9.5" rims with 30mm spacers, I could theoretically install 305 tyres which are no taller than 31.25", yes? That would mean 305.45R20 tyres...

Cross checking this with Cooper, they quote a 305.50R20 LTZ being 32.18"/817mm tall on a 9.5" rim. This is 0.18"/5mm taller than the theoretical height of 32.01"/813mm. So by taking the theoretical height of a 305.45R20 at 30.8"/783mm plus 0.18"/5mm adjustment, I'm at 31"/788mm height...

The section width for 305 doesn't seem to vary much between 12.5 and 12.7", so don't believe that's an issue.

So does that mean I can fit a 305.45R20 tyre to my RRS as long as I have the 30mm spacers installed?

The reason for all this is that the 285.50R20 LTZs are not approved in Oman, however, the Yokohama Geolander AT/S is approved in 305.45R20, so I would if possible like to fit those...

Any feedback would be much appreciated Thank you all in advance.

Have a great Sunday

Cheers

Guy

Guy, oh far too techy for a Sunday morning! Have you tried looking on our sister site where there is a special wheels and tyres section? There is a huge amount of info for D3 over there and RRS is a D3 in smart clothes..........
http://www.disco3.co.uk/forum/wheels-tyres...8143c3fb5d

Both forums are also sponsored by AJS 4x4 which is a specialist tyres supplier and fitter who can give info about what can and cannot be fitted 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Thanks Tim will definitely spend sometime trawling that link!! Looks interesting.

Yeah it is a bit techy for a Sunday, but, I'm into my 2nd day of my working week.. I have a Thurs/ Friday weekend over here maybe that explains the confusion

Will also contact AJS 4x4

Thanks

Guy

No confusion over working week here, I visit Jeddah, Salalah and Jebel Ali regularly and frequently holiday in Egypt/Sinai! 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Hmmm no guessing what industry you work in then

You must pass through Muscat to get to Salalah so if you've got a stop over here in Muscat drop me a PM and we can meet up for a drink.

Guy

Cheers Guy, but I'm in shipping (driving them!) and my ship has just been changed to another trade - China to the US West Coast no more double pay for the Gulf of Aden twice a month, only have to do battle with the US Coast Guard/ Dept of Homeland Security instead! 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

Hey Guyzer,

Im going throught the same problem myself as i want to put my 20's back on and do more off-roading

You can get here in Dubai 285.50R20 NITTO Dune Grapplers or Terra Grapplers or 305.50R 20 in the same, they both get good reviews and the dune grapplers look awesome.

Yellow Hat Dubai and Zafco both sell them and theyre not too pricey. Hope this helps  2006 RRS Supercharged
Hawke Saker 22" rims Nitto Tires
Larini exhaust System
ECU remap
Modified and ported supercharger with 3lb pulley

Cheers for the tip CIAA!! Just found out Zafco are also in Oman so checking there first The problem I've got is the tyre needs to be licensed in Oman otherwise it invalidates the insurance so here's hoping...

Do you think the 305.50R20s will fit in the wheel arches? The garages here a useless and can't tell me!

On another note where did you get the ECU remap and SC pulley upgrade from? Would like to do similar on mine Could you PM me the details and cost?

Thanks again for the info sounds promising.

Cheers

Guy

305s are going to be very tight - see response below from one of the mods on the US site where fatter wheels/tyres tend to be more popular than here:

http://www.rrsport.co.uk/forum/topic11414.html 

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