So I drive a 2009 Lexus RX 350 and they come with 235/55r18 tires. The wheels are 18x7 stock. I got new wheels for my RX which are 18x9.5 and the exact tires would be 255/50r18 or 265/50r18 but there is no tire size for 18’ wheels. The closest I could go for almost perfect replacement is 255/55r18 and 265/45r18.


so here are the spec differences. So the 265 is smaller in diameter by 20mm and the 255 is bigger by 22mm.
my question is which would be a better pick for safety reasons and overall better choice, 255 or 265? Does anyone know which will be a better pick to help me out with choice?

thank you

 

I have 245/50R18 which is a similar diameter to 265/45R18. The smaller tire feels fine on the car, the speedometer will be a little off on the highway and revs will be slightly higher but not by a large amount. The gearing will be a little lower which leads to slightly faster take offs. My MPG was not heavily affected by this change. I tried running a larger size (30.5" from 2016-2022 RX) and it wasn't great, it felt a little more like a newer RX which made it feel slightly boatier / substantial but the fitment was way too close. I would be more inclined to stick with 255/55 though because of your offset. It would be pretty close at full lock with 265. 29" diameter would be more bearable than that larger size I tried though.

 

Do you think I should go with a different tire size Matt? Or should I give the 255 a try? I’ve seen on other forums people have tried 245 with 9.5 wheels and they say it’s stretched and 255 will be a little but is better than the 245. 245/50 is closer to 235/55 in diameter but if I tried those I think it’ll look stretched. But yeah 255 does seem safer than 265. Do you think the 22mm difference with the 255 tire would change a lot of things like speedometer and revs?

 

245 will be the limit I would go on 9.5 rims. 245/35 on 19x9.5" rims is what is on our E46 M3. It's riiight at the limit of width, wouldn't want to go any wider of a rim or narrower of a tire. It's really great to combat sidewall flex on the track but during daily duty you don't really notice the benefits. My 245s on 8" were fine for my RX, but ideally I would have rather had 8.5" rims. Depending on what tire you have some are flared out a little or wider / narrower btw mfrs. The Pilot Sport AS 3 on the '14 RX and the Pilot Super Sports on the M3 I find are pretty tight, accurate to their size and are firm. Other tires like the Blizzak winter tires and Michelin Premier LTXs that come on the newer RX350s are very balloony at the edges.



Excuse the crappy pics, it's really tight in the garage and she's in storage for the winter:

 

Yeah the 245 look nice on your wheels. The sidewall is a lot smaller so it makes it look good. Your wheel looks pretty good I don’t see any curb rashes at all. Since your side wall is smaller to me I can’t really tell its tight on the wheel. Do you think 245/50 is a better bet to go with a 9.5 wheel or should I stick with 255/55?

 

https://www.clublexus.com/forums/rx-...l#post11427215

 

Ok yeah I like 245/55r18 better. I see that matt has it on his m3 without problems and proves that 245 can fit on a 9.5’ wheel. Any recommendations to where to install them? I was thinking about taking it to americas tires because I’ve delivered packages there and the manager there is really cool and I think his staff are good workers too. My dad wants me to go to Costco but I’ve seen the reviews at my local Costco and it seems like the staff there are not that great and I’ve seen photos where they’ve actually scratched some guys bmw wheels and I don’t want to take it there

 

I got my Blizzaks put on at Costco recently and they did it real quick, no hammer on weights like I requested and cheap. I think some good Costcos are out there and some bad.

I steered away from 245/55R18 because of low performance tire choices. I find that hard to believe since one of the previous gen Camaros used this size.

 

That’s good to hear. Maybe there’s hope my Costco. The best tire that I found on Costco and americasbest tires is the same, Michelin CROSSCLIMATE2. It scored 3.5 in overall ride quality and it says its rim width range is 6.5-9’. My wheel is 9.5 so now I’m thinking man the choices for 18’ wheels are not really exactly what I need/want. I know that 19’ wheel has the ideal sizes but I got the 18’s already so I have to make it work

 

Im thinking if I should just try to get an exchange for 19x9.5 25+ and go with 255/45r19 because I’m just not liking the selections for the 18’ wheels. For the 19’ wheel I found a variety of tire selections and I think it’s probably a better choice. What do you guys think? Either way my lug nuts haven’t even came in yet and I don’t think they will for a while

 

That is true 19" does have better tire choices. I like 18" for less unsprung weight and lower costs, but the 19" does offer more performance options and a better overall selection in general.

 

For everyone who stuck around in the thread I want to thank you. All your help and advice, I really learned a lot. I figured out what I’m going to do and once I do it I’ll post an update on new wheels. For right now I wanted to show you guys what I just did to my grille. I think you guys might like it.

I just wanted to share this with you guys so you can see this little touch I added to my Lexus

 

I'd go w/ the 255's w/ the 9.5'' wheels. You'll find a lot of tire brand/type w/ 255's as well as cost. It'll also have a squared up sidewall, same as a 235 on a 8.5'' wheel. Do the wheels your looking at offer a 0 offset?