Alloy Wheels

SIW99 · June 18, 2014

Anyone able to confirm if I can use a set of 18 inch 8.5 J alloys with the same 245 40 18 tyres as the recommended rims for the SC430 of 8JJ ?

Tyres match but struggling to understand rime depth sizes . Tks

CraigIson · June 18, 2014

Yeah you will have no problem getting 245/40's onto a 8.5inch wide wheel. Ive seen 245's on 11inch + wide ....

This is a 245/40/18 stretched onto a 11 inch wide rim. Its No problem at all to do. Even putting the same tire on to a 11.5 inch or 12 isn't too hard.

http://tyrestretch.com/11.0_245_40_R18/11.0_245_40_R18/

Another site to use is Willtheyfit.com ... You put in your wheel measurements "245/40/18 ET50 (ET is your Offset)/18x8" and then punch in your new wheel measurements "245/40/18 what ever your new wheel offset is, and the wheel size and it will show you a diagram to compared old set up to your new one

Personally ... i would run a 245/30 on a 11/12 inch wide wheel ... But hey thats me :P

Hope that helps :)

SIW99 · June 18, 2014

Great I wil get the tyres fitted.

2nd part to the question, will the 18 inch 8.5J alloys fit a car that has standard fit of 18 inch 8JJ rim size ?

any thoughts ?

CraigIson · June 19, 2014

Yeah you won't have any problem fitting them. Normally when you start playing with wheel widths you have to have different offsets to stop the wheels fowling with any suspension components. But half a inch increase won't make any difference.

There is bags of room under the arches for VERY wide wheels. It's only when you start getting into the 11/12 inch wide you will need to start worry about them fowling. This is when you start needing camber etc.

I think when i did some quick working out for wheels for mine, i figured i could get 10.5 inch et25's with 245/30/R19 on the rear with no camber and would still be perfectly legal.

In other words ... You won't have any problems buddy :)

SIW99 · June 19, 2014

Thanks for the advice, i have collected them today and will fit on Saturday.

clemsboy · July 16, 2014

Hi when I was looking for new alloys for my SC I was told that 18 x 8 JJ or 18 x 8.5 J would be suitable. I took the easy way out and replaced them with the exact same size as the original wheels namely 18 x 8JJ. All I know is the JJ is the offset (whatever that means).

I took my car to a great company Motorsport at Sidcup (they have branches all over) they supplied and fitted the new alloys,for a great price, they said if the wheels are not the exact size as per Lexus specification it could affect the ABS system.

Hope this is helpful

John

CraigIson · July 21, 2014

... Well thats me buggered for my 20x10.5 and 20x12 rears

Never heard of there being a issue with ABS systems for any cars tbh. Yes, you could say that wider tires cause more rolling resistance which could effect it, but I've never known of it.

Just so you know "J" is the shape of the Bead that the tire sits in when its mounted, Not the offset. Offset is measured as ET, Which is a measurement from the centre point of the width of the wheel to the mounting surface (in millimetres, For example ET45 is 45mm positive of the centre point. ET0 means the mounting surface is at the same point as the centre point, and ET-45 is negative 45mm's of the centre point.) You can use spacers to effect the offsets, this brings the wheel closer to the body of the car, Effectively making the cars track wider, but with the same width wheels.

Hope that helps :)