phattbam

Just picked up a set of OEM G spiders. Was wondering what would be recommended for daily commute driving Front: 225/40/18 and Rear: 245/40/18 or 255/40/18?? the wheels are non staggered 18x8 all around. They are going onto an IS250 RWD stock suspension.

looking at Bridgestone Potenza RE760 Sport

checked their size specs and supposedly 255/40/18 would be recommended with a 8.5 minimum... just looking for some real life suggestions from possible experiences with running them

BoOst3d

iTrader: (1)

if they are 18x8 all around, why are u gonna run a wider tire in the rear, thats just stupid.

run a 225/40 like u are doing up front in the rear

phattbam

stupid? gosh.. I didn't think we had members with that kind of courtesy here. Well the factory set up on a RWD IS250 is staggered. regardless of wheel width, the rear tires are usually going to be wider on a RWD vehicle. I was just curious to seeing if anyone else has done the same or have positive recommendations other than to say "that's just stupid"

cowsgomoo

iTrader: (2)

I would highly recommend doing the same width in front and rear. For an 8in wide tire you can really go either way, I would do 245 just to have the extra meat on the tire to prevent bends and such.

If you go with different widths of tires you cannot rotate your tires properly and that alone will allow you to maximze how many miles you will get.

Stupid to run different widths on same width wheels? Maybe unwise :-)

phattbam

thanks for the post. I'll check with my local tune shop and see what they recommend as well. thanks. It's not even for my car. I just dont want the driving dynamics to change much

Schnitz

iTrader: (5)

Yup, same tires all around for the same width wheel. Anybody that tells you any different has other motives (profit?).

phattbam

Thanks. I guess I'll be going with the uniform setup. It's not like my gf will be tracking it. I'll post up pics once they are mounted

Toymota

The OEM 17" wheels on the IS are 8 inches wide on both the front and rear, yet the RWD versions run different sized tires 225/45R17 front and 245/45R17 rear. I suppose that makes the Lexus engineers "stupid".

The RE760 in 255/40R18 actually specifies a 9-10.5" rim width, so you should use the 245/40R18 size on an 8" rim for the rears.

phattbam

Thanks toymota for your reply. I noticed that 255/40/18 was going to be too wide for the 8" wide wheel. But I'm going to do the 225 setup all around just for rotating purposes and I hope there shouldn't be any differences in driving dynamics.

GS4_Fiend

iTrader: (22)

I would recommend you get 245/40/18 all around and get some spacers for the rears only so you could do a proper tire rotation.

phattbam

Ended up getting 225/40/18 and 245/40/18. reason was the 225 weren't rated for the load capacity for the rear. Overall it looks good. gave the a nice wash and took some pictures yesterday will post up in the 2IS section later this week.

GS4_Fiend

iTrader: (22)

Isn't the rear 255/40/18 stock?

phattbam

yes. but stock also comes with a 8.5 wide wheel. I had a great deal on some 18x8's plus they were the wheels my GF wanted. so I got them and it's running fine on 245 right now.

phattbam

UPDATE: https://www.clublexus.com/forums/is-...ml#post5470197