[Sahil]

I often find myself overlooking this aspect when purchasing a new tyre. So my question is, How important really is the load index? And what is the permissible limit of variation?

For example, can I put a 94 load index tyre to replace a 98 load index tyre? (3 tyres are 98 and one would be 94 of same thread pattern and brand) Will this cause any noticeable difference or harm?

Tire gurus, would be great to have your inputs on this.


Mods:Could not find a thread on load index, hence start a new one, please merge if one exists already.

[Tejas@perioimpl]

Load index is basically each tyre's capability to carry weight on that tyre.

The difference between a 94 and a 98 indexed tyre would be roughly 100kgs. There are charts online if you look it up.

Now figure out the GVW of your vehicle. GVW means, full tank of fuel with five passengers and luggage (the max your vehicle can hold).

Divide that by the four tyres and you get a weight per tyre.

I know that 100 rating means 800kgs.

So if you fall in the safe limit, go ahead and change.

Hope it helps. Using offroad tyre rating to help you and i assume the rating is same for on road tyres as well.


EDIT:

Looked it up online for you.

This is the site which gives the load rating: http://www.tirerack.com/tires/tirete....jsp?techid=35

So the difference from 98 to 94 is 80kgs. A 98 tyre is rated for 750kgs and the 94 for 670kgs.

Do your math and you will get your result.

[Nikhilb2008]

Technically what Tejas said is perfect.

However, as thumb rule, manufacturers advise against installing a tyre with lower load rating on your car.

[vikram_d]

One important factor to consider is the sidewall strength. The 94 load index tyre will have a weaker sidewall when compared to a 98 index tyre. That means on the same car with all conditions being equal the 94 index tyre will flex more and it's contact patch may also vary.

Edit: Nice read on this topic.

http://www.tirereview.com/Article/59...lity_risk.aspx

[AbhiJ]

One query, wouldn't the front tires require to carry more weight in Indian Cars which are 99% front wheel drive? (Engine+Transmission)

[Sahil]

Reviving my old thread. Exactly two years on, I'm back at the same situation. Last time it was my Superb that was in concern. This time it's my RS5, seems that the only tyres I can source in its odd size of 265/35R19 are Pirelli pZeros which are officially imported with a load index of 94Y whereas the tyres I have are 98Y. The curb weight of the RS5 is 1725kg which is already more than the weight of the load index of 98Y that is 1653kg. 94Y is 1477kg.
The numbers do show that the 98Y is more suited to the cars weight. However if I am unable to source a 98Y, will the 94 load index tyre be more prone to sidewall bubbles/damage?

[shankar.balan]

Originally Posted by Nikhilb2008

Technically what Tejas said is perfect.

However, as thumb rule, manufacturers advise against installing a tyre with lower load rating on your car.

Hi
What is the difference between the OEM Goodyear Excellence tyres' load rating of 95H and these new Falkens which I just fixed, which show a load rating of 98H?

[nfsfreak]

Originally Posted by Sahil

The curb weight of the RS5 is 1725kg which is already more than the weight of the load index of 98Y that is 1653kg. 94Y is 1477kg.
The numbers do show that the 98Y is more suited to the cars weight. However if I am unable to source a 98Y, will the 94 load index tyre be more prone to sidewall bubbles/damage?

Load rating 94, as per earlier values quoted in this thread, should be able to handle 670 Kgs. So, effectively 2680 Kg for all 4 tyres, which is well above your cars kerb weight. right? Please correct me, if my understanding is wrong.

[Nikhilb2008]

Originally Posted by shankar.balan

Hi
What is the difference between the OEM Goodyear Excellence tyres' load rating of 95H and these new Falkens which I just fixed, which show a load rating of 98H?

Your Falkens are rated to take more weight. So, you are safe. Nothing to worry about. Basically the tyres are rated to carry another 240kgs of weight.



The speed rating is H which is 210kmph for both the tyres.

[fry]

Originally Posted by Sahil

Reviving my old thread. Exactly two years on, I'm back at the same situation. Last time it was my Superb that was in concern. This time it's my RS5, seems that the only tyres I can source in its odd size of 265/35R19 are Pirelli pZeros which are officially imported with a load index of 94Y whereas the tyres I have are 98Y. The curb weight of the RS5 is 1725kg which is already more than the weight of the load index of 98Y that is 1653kg. 94Y is 1477kg.
The numbers do show that the 98Y is more suited to the cars weight. However if I am unable to source a 98Y, will the 94 load index tyre be more prone to sidewall bubbles/damage?

Multiple authorities on this subject do clearly state - NOT to replace tyres with a lower Load Index than what the manufacturers recommend/equip!

I would stick to 98Y!
Do update us on how it goes!
Cheers

This is a good guide BTW! The Tire Load Index and Inflation Table guide etc - does get technical.
https://toyotires2-1524598101.netdna...s_20151020.pdf