Tire size/fitment question

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Feb 2, 2010 | 05:43 AM

playa3uhh

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Lexus Test Driver

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From: Florida

Tire size/fitment question

Hey guys. I'm about to get new tires and am putting Lexus ISP-Modes on my SC430. They are staggered 18x8 front/ 18x8.5 rear. My question is what tire size to put on. I was thinking about going 235/40-18 front and 255/40-18 rear. What do you guys think?

Feb 2, 2010 | 10:11 AM

talwang

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From: NASA

For the sc430, you should go with 245/40/18 or 225/45/18 in the front, so the overall diameter is more consistent with 255/40/18.

Feb 2, 2010 | 10:32 AM

playa3uhh

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Lexus Test Driver

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From: Florida

I was thinking about going that route but it seemed like the widths were too similar. I've never had a staggered setup before and all the setups seem pretty wide range, e.g., 225 front with 255 rear or 245 front with 275 rear. So I thought 245 front and 255 rear would be too similar, but I'm not sure. I saw the new Merc E350 Coupe and thought about going that route --> It has 235/40-18 front and 255/35-18 rear. What do you think?

Feb 2, 2010 | 01:28 PM

Ned Vo

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From: Massachusetts

Your set up is only half an inch different between F&R. It wouldn't show much....IMO.

Nov 5, 2010 | 10:52 AM

maisinh

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Joined: Aug 2010

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From: FL

Quote:

Originally Posted by talwang

For the sc430, you should go with 245/40/18 or 225/45/18 in the front, so the overall diameter is more consistent with 255/40/18.

Hi Talwang.
I read alots of your sugesstion. It seems you are a real expert. so I would like to ask you if the diameter is 1" different (front:225/40/18, rear:255/40/18) will it hurt the SC 430 suppentions. I don't care about how it looks just wonder about if SC430 can handle it. Learn alots from you guys.
Thanks

Nov 11, 2010 | 07:31 AM

m3nv

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From: GA

You wont hurt the suspension by going with a 225/255 set up. If I were you, I'd actually go 235/265 but thats b/c I like a lot of rubber on the pavement. Regardless whatever tire you put on the front and rear wont mess up your suspension, it'll only affect the height due to the diameter of the tires.

Nov 11, 2010 | 08:28 AM

Harold57

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From: Texas

Quote:

Originally Posted by m3nv

Regardless whatever tire you put on the front and rear wont mess up your suspension, it'll only affect the height due to the diameter of the tires.

You'll have to play with the tire profile % (the second number in the tire size) to keep the height correct, otherwise your speedometer would need to be adjusted to keep accurate mileage and speed.