Tire size help please

[madstiles]

I currently have 35x12.50r18 Pro Comp xtreme at and am replacing them with Cooper stt pro my issue is they don't have standard sizes all metric so I'm stuck between 305 70r18 or 325 65r18 I don't have a programmer so want to be as close as possible. Suggestions on size appreciated. Thanks for the info!

 

[WJCO]

I currently have 35x12.50r18 Pro Comp xtreme at and am replacing them with Cooper stt pro my issue is they don't have standard sizes all metric so I'm stuck between 305 70r18 or 325 65r18 I don't have a programmer so want to be as close as possible. Suggestions on size appreciated. Thanks for the info!

Use this link, it's not bad:

https://www.tacomaworld.com/tirecalc?tires=305-70r18-325-65r18

Great resource but the measurements are with no vehicle weight on the tire.

EDIT: And this thread too to give you an accurate idea of what you're working with:

http://wayalife.com/showthread.php?35075-The-Ultimate-TRUE-TIRE-SIZE-Database

 

[madstiles]

Thank you! So it would be 1/2 MPH off at most which is ok biggest difference is 325 is .8 " wider than 305 so if a tire is wider would it last longer because it has a greater area to disperse weight? I have tire ocd right now lmao