Thread: Tyres

Hi Discojools,
Could you do me a favour please and measure the distance between the rim and the road (ie the clearance) and also the diameter of the tyre.
Thanks
Peter

Hi Peter,
The diameter of the 275/55/20 is 810.5mm as opposed to the standard 255/55/20 which is 788.5mm. I calculated this using the ExplorerOz.Com website which has a tyre size calculator: Tyre Size Calculator @ ExplorOz Articles

These figures might not be totally accurate as every make of tyre is slightly different.

Difficult to measure the sidewall height accurately but it must be half the extra diameter of 22mm. So 11mm more than the original tyre. I think I have got that right!

Cheers

Julian.

Hi Everyone
This is my first post and I need some help. Against all the advice of friends (and Aulro Posts) I have just completed the Savannah Way from Cairns to Broome, via the Normanton to Borroloola to Roper Bar road, and the Gibb River Road, for the first time, in my SDV6 2015 Range Rover Sport towing an Australian Off Road Quantum Camper.

The only problems I had were predictably the standard tyres on those gravel roads, (the Normanton to Borroloola section being worse than any part of the Gibb when I did it). The RR Sport tyres are the standard Pirelli Grande Verde Scorpion All Terrain 225/55R20. I had one sidewall blowout about 2k from the bitumen heading into Mataranka after a lot of ks on the dirt. On the Gibb after I raised the tyre pressure and nursed the car along I had one tyre with a cut on the tread causing a slow leak and so many other cuts it wasn't worth repairing; and another one that also leaked slowly that could be repaired but also terribly cut about. I started off carrying two spares and at one stage I ended up carrying 4 spares. The tyres had to come from Sydney which is another aspect of the problem.

I am no expert on this and I know this issue has been discussed before but I would appreciate some help. I am led to believe that a Cooper Zeon LTZ will fit the Rangie. Will these be any better than the Pirellis for the gravel roads and what size actually fits the 8? R20 rims? What is the maximum rolling diameter tyre that will fit the vehicle. Does anyone know of any new tyres being developed for the larger rims.

I have looked at the Green Oval Experience rims but they apparently don't have one yet for the 20? rims. Land Rover Australia have not been helpful.

I would like to do more of this travelling but can't trust the current tyres which are more like ballet slippers when I need hob nailed boots. It is a beautiful car and I really don't want to join the Cruiser/Hilux cohort but may be forced to if I can't solve this problem. Any advice?
Cheers

Peter

Have you considered BFG AT KO2 LT 275/55R20 (LI 115) hob-nailed boots? I have them on my L322's 8.5" rims, purchased from a tyre shop in Sydney who direct-imported them ahead of Michelin's schedule for later this year. Cost was $365 ea plus $50 delivery for 5 plus $50 F&B for 5 locally.

Graeme,
thank you for your quick response. These look promising. Do you know of anywhere I can find out what the maximum width and diameter tyre I can fit to a standard RR Sport SDV6 2015. The tyres I have now, 255/55R20, have a diameter of around 789mm. A 275/55R20 would appear to have a diameter of around 810. I don't know if the additional 20mm is critical?
Peter

Peter,
I have 275/55/20 Pirelli Scorpion ATRs fitted to my SDV6 Sport. There is no issue with rubbing so no problem. You would be wise to check the "actual diameter" of the BFGs as there is sometimes a slight difference in diameter. With the original tyres the speedo used to show 104kph when actually doing 100kph, now with the ATRs it shows 102kph at actual 100kph. These tyres are as quiet as the originals and better on dirt roads. They also have a stiffer (therefore stronger) sidewall so the ride quality does suffer a little. I got mine from Tyresales I think about $360 each.
Went on a big trip to Simpson Desert and Hay River track in April, did many ks of rough dirt tracks, dunes and roads. My friend's new RRS SDV6 was fitted with these tyres and they performed perfectly well.
Very interested to see Graeme's post re the BFGs.. If I had known I might have waited and got a second set of wheels to fit them to and kept the OEMs for the highway.

Jools.

Tirerack list the BFGs as 31.8" rather than the nominal 31.9", so smaller rather than larger. However the BFGs are very square whereas the ATRs are not so, hence the BFG's edges could possibly scrape, perhaps on full lock, when the ATRs don't. With the L322's rims having a more positive offset (rim centre is further inwards) than the L405/L494, there is not much point in trying a BFG fitted to an L322 on your vehicle. However with this size tyre being less than 1" larger diameter than standard L405/L494 and therefore less than 0.5" larger radius, the size is unlikely to be problematic.

Just thought I'd ask if anyone has used BFG on new RRS yet? Any thoughts? Looking at buying a 2016 TDV6 SE and based on these forums it looks like I need to upgrade from 19 to 20inch rims to get decent AT tyres with strong side walls....its a shame there are no tyre co's effectively catering for 19's on a RRS. Also can anyone offer any feedback on cooper Zeon ltz? Or anyone doing heavy work on Scorpion ATR's with no sidewall damage or blowouts?