Switching rims, wheel/tyre size

[ekay1]

Hey guys, im just wondering if im changing my wheels to a large size from stock ( from 15 to 18), can i simply just DIY change the rims or would i have to get them balanced etc?
How would i know which tyre size would fit the rim?
Any tips and advice? Thanks :)

[Lukey]

try this site to work out tyre sizes

http://www.miata.net/garage/tirecalc.html

[JDM.AS.FCK]

Hey mate, umm well firstly, if you're going to be going from 15" to 18" that is a substantial increase which may affect your speedometer readings and in some cases also affect the wheel speed sensors which are a part of your abs system and this will bring up a warning light on your dash.

In regards to needing to balance the wheels or not, i'd suggest you get them balanced before putting them on as this will reduce your chance of annoying vibrations through the steering as well as the passenger compartment, this shouldnt cost too much at any tyre retailer and if you are looking to purchase tyres from them and have them fitted too, you dont need to worry about balancing as they will do this when they fit the tyres anyway.

But yeah, in regards to what tyres fitting on what size rims..usually when a tyre has a size stamped on the size this is what they mean for example 225/40/R18 91Y..225 means the width in mm, 40 meaning the profile, also known as the aspect ratio of the tyre compared to its width, R18 mean to fit rim diameter of 18inch and 91Y is the speed rating. Although when you are deciding what tyres to put on your rims check your tyre plachard on the side of ur driver or passenger rating and make sure you get similar or higher speed rating to ensure safety. If you look on the back of your rims you should find a size stamped on it, for example 18x7.5jj etc..check to see what it says and let me know as i'll be able to find out what the best size tyre would be for your rims, depending if you want them to sit flush or have that stretched look.

Hope this helps you in someway to answer your questions

[ekay1]

Hey mate, umm well firstly, if you're going to be going from 15" to 18" that is a substantial increase which may affect your speedometer readings and in some cases also affect the wheel speed sensors which are a part of your abs system and this will bring up a warning light on your dash.

In regards to needing to balance the wheels or not, i'd suggest you get them balanced before putting them on as this will reduce your chance of annoying vibrations through the steering as well as the passenger compartment, this shouldnt cost too much at any tyre retailer and if you are looking to purchase tyres from them and have them fitted too, you dont need to worry about balancing as they will do this when they fit the tyres anyway.

But yeah, in regards to what tyres fitting on what size rims..usually when a tyre has a size stamped on the size this is what they mean for example 225/40/R18 91Y..225 means the width in mm, 40 meaning the profile, also known as the aspect ratio of the tyre compared to its width, R18 mean to fit rim diameter of 18inch and 91Y is the speed rating. Although when you are deciding what tyres to put on your rims check your tyre plachard on the side of ur driver or passenger rating and make sure you get similar or higher speed rating to ensure safety. If you look on the back of your rims you should find a size stamped on it, for example 18x7.5jj etc..check to see what it says and let me know as i'll be able to find out what the best size tyre would be for your rims, depending if you want them to sit flush or have that stretched look.

Hope this helps you in someway to answer your questions

Thanks man really helped

[curtis265]

and then, plug your old and new wheel data into here: http://www.willtheyfit.com/

then u can visualise the difference in dimensions, example:
http://www.willtheyfit.com/wheelimage.php?tyrediameter=559.1&tyrewidth=185&tyrecirc=1756.464450615&wheelwidth=152.4&wheeldia=355.6&offset=38&poke=38.2&inset=114.2&aspect=55&tyrediameter2=531.1&tyrewidth2=195&tyrecirc2=1668.499856415&wheelwidth2=203.2&wheeldia2=355.6&offset2=20&poke2=81.6&inset2=121.6&aspect2=45

[ekay1]

Thanks curtis!