Tyre Load Speed Ratings

Chris111 · August 19, 2016

Firstly I must say that this isn’t a request for a tyre recommendation. I’m just after advice about the tyre load speed rating.

My GS’s tyre load speed rating is stated as 93 but, as I’m sure many of you have also found, when looking for tyres online the ones with higher load speeds are also included. In my case that means the ones with a rating of 97 or 97 XL are also shown. Now, from researching this I understand the differences in these load ratings but I want to know if it worth increasing from 93 to 97 when I replace my tyres? And do I go for XL also? As I understand it the XL tyres have a reinforced sidewall and are designed for bigger cars and cars that regularly carry a lot of passengers and/or cargo (to me that means estate cars or people carriers). I don’t do this but the GS could fall into this category as it is a big heavy car. However, I would have thought that if the GS needed tyres with a 97 XL load rating then wouldn’t Lexus have fitted tyres with this rating when they left the factory? Am I also right in thinking that a tyre with a higher load rating needs to be inflated higher?

My confusion on this matter only grew when I recently had an online conversation with the Dunlop “tyre doctor” as I wanted to know why their website they didn’t recommend the Sportmaxx RT2 for the 450h. They subsequently insisted that this tyre in 97 XL guise would be perfect for my car. When I pointed out that the tyre spec from Lexus only called for a load speed rating of 93 their response was that in 97 XL guise “this tyre can do all that is required of a 93Y rated tyre and more.” When I asked them to expand on this, their only response was to say “an XL tyre can carry higher loads than a standard load tyre.” I already knew that an XL tyre would do that so is that the ‘more’?

So what I really want to know is what will be the difference to fitting a tyre with a higher load speed rating and what are the benefits, if any?

Any comments and information will be gratefully received.

Many thanks

Chris

egolex · August 19, 2016

Chris111 · August 19, 2016

Hi

Many thanks for your quick response.

I did already know the weight difference in the load ratings. I want to know how / if the increase of an extra 80kg load weight per axle makes a difference and would it benefit me to increase the load rating. Forgive me if this table tells me, I can't see it.

Many thanks again

Chris

rayaans · August 22, 2016

On 19/08/2016 at 7:15 PM, Chris111 said:

Hi

Many thanks for your quick response.

I did already know the weight difference in the load ratings. I want to know how / if the increase of an extra 80kg load weight per axle makes a difference and would it benefit me to increase the load rating. Forgive me if this table tells me, I can't see it.

Many thanks again

Chris

Essentially a tyre with a higher load rating will have a stiffer sidewall, therefore you might feel a harsher ride. There is no benefit to increasing the load rating on these cars, unless you're frequently filling up with VERY heavy items.

Chris111 · August 25, 2016

Thanks for that Rayann. You confirm what I suspected in that there is no real benefit in increasing the load rating unless it is for the reason you state. Just confuses me as to why the Dunlop "tyre doctor" was insistent that the 97 XL tyre was the one to go for. Can't be price as there is not much difference between them.

colin79666 · September 6, 2016

Came across this the other day when looking at tyres myself:

http://www.oponeo.co.uk/tyre-article/reinforced-tyres-advantages-and-disadvantages

Chris111 · September 20, 2016

Thank you Colin. I had come across that article, along with numerous others.

If I understand correctly it is basically saying that with an XL tyre you can carry heavier loads, traction, cornering and braking are improved, and it will travel further but, due to the extra rigidity, you will experience a harsher ride and suffer increased fuel consumption.

In real world driving are these differences very apparent?

I'm about to purchase a new set of tyres and that is the reason I started this thread as I wanted other's opinions on the benefits or not of fitting XL ones. Looking at it I'll stick with the standard specification. As I questioned above, if the XL tyre is needed, wouldn't Lexus have fitted them as standard? Safety and comfort are my priorities but I am a firm believer in not skimping when it comes to tyres, as they are too important, Everyone will have their own opinion about which tyre is best but I have narrowed my choice down to either Dunlop SportMaxx 2 or Continental ContiSportContact 5.

Once again thanks for your responses

Chris

rayaans · September 21, 2016

In real world terms, you'll notice the ride difference more than the others. Its not very often you'd go around a 20mph turn at 50mph so it shouldn't make much difference.

The Dunlop Sportmaxx 2 are good tyres, be aware that the contisportcontact 5 has shocking tread life though as its a very soft, grippy compound.

colin79666 · September 25, 2016

Since I posted the above I've actually gone and had XL tyres fitted to by CT 200h. The ride is every so slightly firmer but really there is little difference.

Note there is a lot of mis information on the internet about the relationship between load rating, tyre pressures and XL/reinforcement. A XL tyre at the same pressure as a regular tyre will not actually have the same load rating. The reason being they only take a greater load at higher pressures. So a 87 rated normal tyre at 2.4 bar will take more or less the same load as a 91 XL tyre at 2.4 bar.

When I was looking at winter and all season tyres they mostly seem to be XL, perhaps due to needing extra reinforcement to offset the softer compound or perhaps just because they are trying to maximize the range of vehicles it will be compatible with.

For summer tyres I'd go for the normal tyres if that is what is in the handbook because there is little point sacrificing comfort and paying more for something not needed. If you are looking for an all season (Michelin Cross Climate was my choice) or winter and they only come in XL then I wouldn't worry. If the vehicle comes with XL tyres from the factory then you must only replace them with XL and of the same or higher load rating.

Chris111 · October 6, 2016

Thanks for your replies Rayann and Colin.

I had read a lot of driver reviews which slate the Continental for their wear so I'm probably going to go with Dunlop, although I have just come across the new Vredestein Ultrac Satin tyre. Ironically it is only available in XL guise but the labelling states an 'A' for rain, and 'B' for economy. Although I have not come across any official tests including this tyre the driver reviews are all extremely positive. They are also significantly cheaper but that is one thing I don't take into consideration. I had Vredestein on a previous car and quite liked them.

I also considered all season tyres but very few are available in the GS's size. Of the ones I have found most of the makes I have never heard of, and only one tyre has the 'Y' speed rating required. As is happens that too is a Vredestein tyre. The Quatrac 5, but in the tests I found that included this tyre is was slated for its wet braking, wet handling and aquaplaning abilities. Not what I want living where I do!

However, I would be very interested to hear form you Colin as to how you find the Michelin Cross Climate tyre as I am looking to get a set of all season tyres fitted to my wife's car and am seriously considering these for it.

Chris

colin79666 · October 8, 2016

On 06/10/2016 at 5:26 PM, Chris111 said:

However, I would be very interested to hear form you Colin as to how you find the Michelin Cross Climate tyre as I am looking to get a set of all season tyres fitted to my wife's car and am seriously considering these for it.

Got a running thread on them over in the CT200h area Chris: