Thread: Tyre plaque / FAQ and hand book - please explain

Makes you wonder who comes up with all these figures. The standard D4 HSE rims are rated at 930kg so a 106 (950kg) load rating for the tyre would be above the rims capacity. The minimum load rating on the placard is 109 (1030kg), 100kg greater than the rims and the 112's nearly 200kg!

Tyre loads are quoted at the tyre rated speed. So if the rims have a higher speed rating it might be that they would have the equivalent of 110/112 load rating at lower speed?

Having said that I think the rear axle load rating is also about 1850kg or 925 per corner.

The tyre, as first point of contact and with more flexibility, will experience slightly higher load. Some of this is dissipated as heat, hence less is transmitted to the rim. Ergo the rim can be rated lower. One of the reasons that LR won't allow 22" rims and ultra-low profile tyres, is not enough is dissipated by the tyre and too much load is transmitted to the suspension components.

Cheers,

Gordon

Originally Posted by dukemasterpro

Had this happen to me when about to order at3 in 18 inch for a D4. The guy at bob jane said he could not officially recommend a tyre with a load rating of 110 when 112 was required. I can see that 109 is allowed with a 20" rim on the d4 - is the At3 going to be legal?? There does not seem to be any other at options in this side apart from the Pirelli atr ( which does not get a good rap and is more $$$)

I have had a set of AT3 265/60/18's on my D3 for about 25k now and they are excellent tyres, handle really well, little to no road noise, good in the wet and so far seem pretty good off road.

I bought mine not long after they came out for $300 a corner fitted.

cheers,
Terry

It seems our LR3's here in North America require the XL, (Extra Load), Load Range rating as well as the Load Index, (such as 110), and Speed Rating, (such as H), minimums that are on the door plaque.

I note that the owners manual here seems silent on the XL requirement as does the door plaque, however the tyres that come standard on the LR3 and now LR4 are all marked XL , (Extra Load) or RF, (Reinforced).

Tire Tech Information - Load Range/Ply Rating Identification

Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions

I just wondered if there was any formal side wall rigidity requirement in Australia?

Today, I removed my 18" winter tyres and installed my newly purchased summer tyres, Bridgestone Alenza H/L 255 55 R19 XL 111V M+S. The cost here was about $1,100 mounted and balanced from the local Firestone dealer.

The link below is to the tyres if anyone is interested in the specs.
Bridgestone*Dueler H/L Alenza Rover&autoYear=2005&autoModel=LR3 HSE&autoModClar=

For winter, I have on order, the narrower Pirelli Scorpion Ice and Snow 235 65 R18 XL 110H M+S and Snowflake. These replace my Dunlop ST8000 M+S that are no longer made - was a pretty good tire to my mind as well.

Pirelli Scorpion Ice & Snow - Canadian Tire

Originally Posted by bbyer

It seems our LR3's here in North America require the XL, (Extra Load), Load Range rating as well as the Load Index, (such as 110), and Speed Rating, (such as H), minimums that are on the door plaque.

Just because it's fitted, doesn't mean it's legally required. I can't see how any statutory body could enforce a nebulous quantity such as "Extra Load" that has no quantitative definition? As long as you comply with the load and speed ratings, that should be sufficient. Let's not try to make it any more complicated than it is.

Cheers,

Gordon

Trying to find a tyre in the stock sizes with an XL or RF rating can be a real complication.

Re my on order 235 65 R18 XL, the Pirelli Ice and Snow was about the only narrow winter tyre I could find here and it is a special order, (not regularly stocked), hence buy now, wait, and maybe we will have them for you in time for winter.

Talking to tyre shops guys, the apparent rational for the XL rating is that the 3 is short wheel base, (compared to conventional pickups here), heavy, (again compared to pickups that do not require the LT tyre), and SUV's like the 3 tend to get stuff piled on the roof rack and hence the centre of gravity starts to rise.

Some argue that the stiffer sidewall is a deemed solution for these realities if one considers them to be potential problems.

Originally Posted by bbyer

Some argue that the stiffer sidewall is a deemed solution for these realities if one considers them to be potential problems.

There _is_ no argument - if your tyre plaque doesn't specify "XL" (and it doesn't) you need only comply with the plaque and it's interpretation under the relevant statutes for your state. Anything else is tyre shops trying to squeeze a little more money off you.

Cheers,

Gordon