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Hello, I have a 2015 NX200t F Sport with 225/60/18 tires. That's also what's listed on the door of the SUV. Do I have any other choices for tires using the same wheels? In other words, could I put on 225/65/18 or 225/55/18? I went onto Tire Rack and for my specific vehicle/year/model they list what I have(225/60/18) but they also list a 235/55/18. But, I'm guessing that's only if your vehicle had 235/55/18 to begin with. One of the reasons I want to know is because I can get the one size off someone for alot cheaper.
There's a few things to consider when looking to change tire size. The first major one is the "overall diameter" of the tire. If you bought different size tire, it would throw off the accuracy of the speedo. You need to get tire with same diameter.
Next, it would be is the "section width". If you buy a tire which is too wide, it could rub inside the fender when turning or hitting bumps.
Last, you need to consider the "load rating" which corresponds to the weight capacity of each tire at max inflation. You must buy a tire which at least equals the OEM load rating of the tire which is expressed in lbs. Example would be 93V tire can handle 1433lbs per tire vs 94V which is 1477lbs. The letter is of course the speed rating of the tire.
Thanks a bunch, appreciated. From what I understand, and that may not be alot, when you change size(obviously not the 18" wheel and tire size) the combination of the two, in some math equation, has to equal one another?
So, perhaps this is wishful thinking, but I believe you can use either an 225/60/18 or 235/55/18
Actually, they are NOT the same specs and interchangeable.. They have different diameters (225 is taller than 235) and also 235 is slightly wider (might get rubbing)
See attached
Thanks again. Given your info, while the width wouldn't affect those figures, in particular, the revs/mile, the aspect ratio would. Anyway, I googled "tire size calculator" and compared what I have now, 225/60/18 with what I wanted to purchase, 235/55/18. While the results were very similar, they weren't the same. So, am I correct in assuming that this difference would affect the accuracy of MPH and miles driven or, is this not the case?
It would throw off your speedo based on those calculators, You'd be going 1 to 2 mph slower than the speedo shows, In turn, miles on vehicle affected as well.
The section width issue while not affecting these things might have clearance issues as well as tire itself is wider with the 235.
As the 55 are lower profile, it would probably affect ride quality as well due to lower sidewall.
Up to you...... IMHO don't think it is gonna get you much.
Thanks. I would be getting some almost new 235/55/18 tires for almost free. I wasn't sure how the speedometer works, if it's from wheels, axle or something all together different. For 2015 NX200 F Sport AWD, Lexus equipped them with either 225/60/18 or 235/55/18. I was hoping I could switch to 235/55/18.
Understood. Didn't know they offered different tire sizes back then. I was going by my wifes NX which is a 2020 (non F sport) & came with 225/60/18 Yoko Geolanders which are not a good tire at all. Kind of noisy, lousy treadware, etc & expensive as hell to replace... far more $$$ than other brands simply because they are an OEM size. Guess they figure some owners will just slap on the same tires without thinking.
Once they are shot, I will replace with Pirelli.... most likely new Scorpion AS3.
It came as a factory option, you will be fine switching. I myself am switching the Bridgestones that came on my 19 300 F-Sport and going down to the lower profile 235/55/18 so I can go back to DWS 06 tires which I find the best overall fit for me.
Thanks. I would be getting some almost new 235/55/18 tires for almost free. I wasn't sure how the speedometer works, if it's from wheels, axle or something all together different. For 2015 NX200 F Sport AWD, Lexus equipped them with either 225/60/18 or 235/55/18. I was hoping I could switch to 235/55/18.
The vehicle speedometer sensor is typically located at the transmission or transaxle but a smaller tire diameter will still cause a lower speedo reading which will reduce your vehicle's overall mileage reading, which works in your favor. A smaller wheel diameter will cover less distance per revolution of the wheel and transmission.
If you replace your old 225/60/18 tires with 235/55/18 tires, according to the speed error calculator below, you will only have an error of -2% which is acceptable in my opinion. I think you will be fine as long as you do not mix and match the different sizes.
You know, on most every vehicle I or my wife owned since new, the OEM tires are awful whether they're Goodyear, Cooper, Michelin, etc. One common denominator is that they all wore out very quickly.
The vehicle speedometer sensor is typically located at the transmission or transaxle but a smaller tire diameter will still cause a lower speedo reading which will reduce your vehicle's overall mileage reading, which works in your favor. A smaller wheel diameter will cover less distance per revolution of the wheel and transmission.
If you replace your old 225/60/18 tires with 235/55/18 tires, according to the speed error calculator below, you will only have an error of -2% which is acceptable in my opinion. I think you will be fine as long as you do not mix and match the different sizes.
I suppose then that Lexus would alter the car in some manner, one particular version for each of the two tire sizes. Or, would it be just the wheels that need to be different? I was hoping the stickers on the door jamb would show both sizes but it's only the one.
I suppose then that Lexus would alter the car in some manner, one particular version for each of the two tire sizes. Or, would it be just the wheels that need to be different? I was hoping the stickers on the door jamb would show both sizes but it's only the one.
Thanks
I am not sure if Lexus has a different ECU program for the two different size tires since they are so close.
09-25-21, 02:16 PM
Tires for 18" wheels
