Can someone explain this?

[Mohamed Gobara]

Hey guys,

This is probably a stupid question , but why does Tesla or any manufacturer choose to put two different tires on the front and back.

For example: why is the Model S front tire a 35 but the rear tire is a 30?

 

[E90alex]

Wider rear tires for better traction on the main drive axle. Usually common on performance vehicles.

 

[Mohamed Gobara]

Wider rear tires for better traction on the main drive axle. Usually common on performance vehicles.

Wider tires i understand. But why 30 on the rear and not 35 like the fronts

 

[ucmndd]

Wider tires i understand. But why 30 on the rear and not 35 like the fronts

That number is an aspect ratio (tread width to sidewall). So a wider tire needs a smaller aspect ratio to maintain the same overall circumference.

 

[Masi]

Tire side wall is decreased to accommodate for the wider rear tire. You would would to do this to keep the same rolling diameter as close to stock as possible.

 

[airborne spoon]

Wider tires i understand. But why 30 on the rear and not 35 like the fronts

It sounds like you don't know what the numbers on your tire mean.
In the case of my tires 245/45/19 the first number is how wide the tire is in mm. The second number is the ratio of height to width, and the last is the diameter of the rim its made to mount to.

So to have a tire maintain the same overall circumference the ratio has to be different on a tire that is wider or narrower than the other.

 

[Gumball]

So yes, someone could explain it.

 

[Mohamed Gobara]

Haha. So theoretically if i was cheap and wanted to save some money i could go 285/35/21 all around on the arachnid wheels?

 

[E90alex]

Haha. So theoretically if i was cheap and wanted to save some money i could go 285/35/21 all around on the arachnid wheels?

No. The wheels are different sizes and 285/35/21 is the wrong size for both axles.