Tire Sizes

[ppjcs]

I recently bought used 2020 Wrangler JLU Rubicon. It has 35x12.5x17LT tires on it. I am not used to this type of tire numbering. I am more in tune with 285x70x17LT Are these comparable sizes? What is the difference?

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[Bulletbill]

35” vs 33”.
https://tiresize.com/calculator/

 

[Ratbert]

People that are into trucks are usually much more concerned about the height of a tire than its width and aspect ratio. It's easy to compare a 35 to a 37 from that perspective.

People that are into sports cars, on the other hand, tend to focus on width and aspect ratio. Aspect ratio has a massive impact on handling versus comfort.

And people that perceive their vehicles as something that gets them from point A to point B tend to not give a damn.

 

[Voodooridr]

I love the TireSize website, tons of useful information
Tire Size Comparison

 

[AZJeepGuy]

That's a pretty standard size for those that upgrade to a larger tire. A 315 is a little short, around 34". But they all vary so look for the actual size when researching.

 

[Ratbert]

That's a pretty standard size for those that upgrade to a larger tire. A 315 is a little short, around 34". But they all vary so look for the actual size when researching.

And when you're looking for "actual size" you're looking for diameter in inches. That's the standard that (in the Jeep world, at least) is used.

Unfortunately "diameter in inches" isn't even something that we can count on as reflecting reality.

 

[[DELETED MEMBER 103062]]

I recently bought used 2020 Wrangler JLU Rubicon. It has 35x12.5x17LT tires on it. I am not used to this type of tire numbering. I am more in tune with 285x70x17LT Are these comparable sizes? What is the difference?

The difference is simple english units vs a more complicated metric tire sizing system.

You said have a tire that is 35" in diameter, 12.5' wide and fits on a 17" diameter wheel. The LT stands for Light Truck. This is a simple system to understand tire size.

The metric system is a bit more complicated. For your example of 285/70/17LT the 285 is the width in millimeters which is equivilent to 11.22". the second number is the aspect ratio of the side wall which means the sidewall height is 70% of the width. 70% of 285 is 199.5 millimeters which is 7.85" and the 17 is the wheel diameter in inches. To find the overall diameter you multiply the aspect ratio by 2 (sidewalls top & bottom) and add the wheel diameter. So for your example, the tire diameter is 2 x 7.85"+17" = 32.7".

A tire size conversion website will help with quickly comparing to the english equivilent of the metric sizes.

You can use metric sizing up to a point to get close to tires sized with the english system but they won't be exactly the same. Tires using the english sizing are also more expensive compared to a metic size that are close is size. Lastly the really big tires tend to not be available in the metric sizes.

 

[ppjcs]

35” vs 33”.
https://tiresize.com/calculator/

Thanks that helps a lot! and Thanks to the others who replied as well.

 

[Padre]

As others have mentioned, this is a great site:
https://tiresize.com/calculator/

Here's a good site for comparing metric sizes. It's useful for comparing not only different tire sizes, but the effects of wheel width and offset:
https://www.willtheyfit.com/

Another useful site, which converts metric to inches and vice versa. This is useful because when a tire is advertised in inches only, you can convert it to an equivalent metric to use on the above sites for comparison:
https://www.crawlpedia.com/tire_size_converter.htm

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