Tyre Size Calculator

[wastedagen]

I'm hoping to be changing my wheels this summer to either 17's or 18's but I was doing some window shopping and come across this on tyre sizes.

Tyre Size Calculator

If the new wheels are too much out then won't that effect the speedo? Is the speedo set to 16" wheels. Unless you have 17" from the factory then I assume it will be set to that.

And if I have puncture and only a 16" space saver, will it be ok to use 2 different size wheels on the same axel?

Thanks in advance ;)

[Auris 1.6 vvt-i]

I'm hoping to be changing my wheels this summer to either 17's or 18's but I was doing some window shopping and come across this on tyre sizes.

Tyre Size Calculator

If the new wheels are too much out then won't that effect the speedo? Is the speedo set to 16" wheels. Unless you have 17" from the factory then I assume it will be set to that.

And if I have puncture and only a 16" space saver, will it be ok to use 2 different size wheels on the same axel?

Thanks in advance ;)

As long as the outer diameter is the same, you are good. The Auris' standard tire size is 205/55 R16, so if you wanna go 17, you need 225/45 R17 and for 18's, the best size would be 245/35 R18. When the tires get too wide dough, you need to consider the wheels' ET ( the offset) as yo don't want your tires to scrape on the bumper or the underskirts(? not quite sure about this word) when making a turn. Also, about the spare wheel - again as long as the outer diameter of the tire is the same, you are good. Example:

205/55 R16's diameter is 632 mm and 225/45 R17's is 634 - so there is a 2 mm difference, which is not crucial

[Johan007]

Check out the price of tires or you will be in for a shock. 16" high performance tires are very cheep compared to 18". There will be no performance increase too... just a harder ride.

[Toscane]

...Auris' standard tire size is 205/55 R16, so if you wanna go 17, you need 225/45 R17 and for 18's, the best size would be 245/35 R18...

Not exactly...

225/45/17 for 17"

225/40/18 for 18"

These are the correct sizes for Auris, 245/35/18 is an overkill and wrong.

[Auris 1.6 vvt-i]

225/40/18 for 18"

These are the correct sizes for Auris, 245/35/18 is an overkill and wrong.

Yeah, I guess you are right 225/40 18 are only 2 mm higher than 245/35 18 and 5 mm higher than 205/55 16, so not such a biggy and 245 is too wide indeed!

[wastedagen]

Thank you guys for your advice. Much appreciated.................