Go Back   Team-BHP > Under the Hood > Modifications & Accessories > Tyre & Alloy wheel Section


Reply
 
Thread Tools Search this Thread
Old 3rd February 2014, 13:22   #1
Distinguished - BHPian
 
Sahil's Avatar
 
Join Date: May 2004
Location: Bombay
Posts: 5,202
Thanked: 2,094 Times
Default Tyres: The importance of Load Index

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.
Sahil is offline   Reply With Quote
Old 3rd February 2014, 16:40   #2
Distinguished - BHPian
 
Tejas@perioimpl's Avatar
 
Join Date: Sep 2008
Location: Bombay
Posts: 3,963
Thanked: 4,881 Times
Default re: Tyres: The importance of Load Index

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.

Last edited by Tejas@perioimpl : 3rd February 2014 at 16:44. Reason: See Edit.
Tejas@perioimpl is offline   (5) Thanks Reply With Quote
Old 3rd February 2014, 16:54   #3
Distinguished - BHPian
 
Nikhilb2008's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 4,825
Thanked: 4,796 Times
Default re: Tyres: The importance of Load Index

Technically what Tejas said is perfect.

However, as thumb rule, manufacturers advise against installing a tyre with lower load rating on your car.
Nikhilb2008 is offline   (4) Thanks Reply With Quote
Old 3rd February 2014, 17:09   #4
Senior - BHPian
 
vikram_d's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 2,380
Thanked: 936 Times
Default Re: Tyres: The importance of Load Index

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

Last edited by vikram_d : 3rd February 2014 at 17:18.
vikram_d is offline   (4) Thanks Reply With Quote
Old 3rd February 2014, 19:56   #5
Senior - BHPian
 
AbhiJ's Avatar
 
Join Date: Jun 2008
Location: Kolkata
Posts: 1,298
Thanked: 462 Times
Default Re: Tyres: The importance of Load Index

One query, wouldn't the front tires require to carry more weight in Indian Cars which are 99% front wheel drive? (Engine+Transmission)
AbhiJ is offline   Reply With Quote
Old 16th March 2016, 02:00   #6
Distinguished - BHPian
 
Sahil's Avatar
 
Join Date: May 2004
Location: Bombay
Posts: 5,202
Thanked: 2,094 Times
Default Re: Tyres: The importance of Load Index

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?
Sahil is offline   Reply With Quote
Old 16th March 2016, 04:16   #7
Senior - BHPian
 
shankar.balan's Avatar
 
Join Date: Apr 2008
Location: BLR
Posts: 8,027
Thanked: 5,325 Times
Default Re: Tyres: The importance of Load Index

Quote:
Originally Posted by Nikhilb2008 View Post
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?

Last edited by shankar.balan : 16th March 2016 at 04:21.
shankar.balan is offline   Reply With Quote
Old 16th March 2016, 12:04   #8
BHPian
 
Join Date: Dec 2010
Location: Bangalore
Posts: 301
Thanked: 98 Times
Default Re: Tyres: The importance of Load Index

Quote:
Originally Posted by Sahil View Post
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.
nfsfreak is offline   Reply With Quote
Old 17th March 2016, 20:48   #9
Distinguished - BHPian
 
Nikhilb2008's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 4,825
Thanked: 4,796 Times
Default Re: Tyres: The importance of Load Index

Quote:
Originally Posted by shankar.balan View Post
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.

Name:  tyre_load_index.jpg
Views: 230
Size:  36.5 KB

The speed rating is H which is 210kmph for both the tyres.
Nikhilb2008 is offline   Reply With Quote
Old 28th March 2016, 12:50   #10
fry
Newbie
 
Join Date: Apr 2006
Location: bombay
Posts: 24
Thanked: 7 Times
Default Re: Tyres: The importance of Load Index

Quote:
Originally Posted by Sahil View Post
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

Last edited by fry : 28th March 2016 at 13:20.
fry is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Upsized my Civic's tyres. Now scraping under load! keertan Modifications & Accessories 14 8th June 2011 14:35
What is your Reliability Index? - For Vista Users clevermax Gadgets, Computers & Software 23 20th November 2008 12:14


All times are GMT +5.5. The time now is 16:59.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks