B arry's Tire Tech

This is a series of articles on the technical aspects of tires, their care and usage.

My primary purpose in these articles is to help people understand tires and thereby reduce the risks we all face every day.

..........and since tires is just about the only thing I know about..........

Please drop me a note if you have a topic you want to see:

Barry@BarrysTireTech.com
LL Tires

LL (Light Load) tires are similar to SL (Standard Load) or XL (Extra Load) tires. They are Passenger Car (PC) tires with a given load rating - in this case less than an equivalent SL.

Below is a page from the 2020 Tire and Rim Association (TRA) Yearbook showing some of them.

Notice that the rated inflation pressure for LL tires is 35 psi - just like the SL - but the rated load is about 8% lower than the SL.

Also of note is that neither ETRTO (European Tyre and Rim Technical Organization) nor JATMA (Japanese Automobile Tire Manufacturers Association) have LL entries - only the US based TRA!

My best guess as to why LL tires exist is that this was a quirk in the old TRA load formula - and since TRA can't undo something they've already published, they created this rating.

Can you use LL tires in place of SL tires?

No! They carry less load for the same inflation pressure

HOWEVER, this is not likely to happen.

LL tires are pretty rare. I've only found them in 3 places:

  • Some racing tires are produced in LL - and since racing cars - even street based cars - are the opposite of fully loaded, the LL load is OK.
  • There were some Corvettes that specified LL tires - and in this case using the higher load rated SL tires would be OK. (I suspect this is what started this mess!)
  • There are some compact spares that use LL.

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