Notices
IS - 2nd Gen (2006-2013) Discussion about the 2006+ model IS models

Newbie tire question

Thread Tools
 
Search this Thread
 
Old Sep 22, 2007 | 07:54 PM
  #1  
supa_89's Avatar
supa_89
Thread Starter
Rookie
 
Joined: Sep 2007
Posts: 81
Likes: 0
From: NJ
Default Newbie tire question

I am looking to change my 17" for some 18" aftermarket wheels. I see everyone upgrading to 19's and 20's but thats not me. I was told if I wanted a smoother ride I should get a different size tire so instead of 225/45/17 on my IS 250AWD I should get 225/50/17 or 215/55/17. My question is, Can I fit 215/50/18 or 215/55/18 on my IS 250AWD without touching or rubbing?

Please Advise me...
Reply
Old Sep 22, 2007 | 08:31 PM
  #2  
FiveOhNine's Avatar
FiveOhNine
Lexus Champion
 
Joined: Jun 2007
Posts: 1,674
Likes: 0
From: Dark side of the moon
Default

I think tires that tall would look off on the IS, regardless of wheel diameter. Higher profile tires do tend to give you a bit better ride, but they sacrifice performance. Even if you aren't into performance, I would think twice about compromising your ability to avoid obstacles. Your steering response, turn-in and a number of other aspects will suffer.

Is your standard setup that bad?

What tire pressures are you using?
Reply
Old Sep 22, 2007 | 08:43 PM
  #3  
Namir's Avatar
Namir
Lead Lap
 
Joined: Aug 2007
Posts: 462
Likes: 0
From: OH
Default

larger sidewalls won't necessarily affect performance, Nascar Indy Forumla 1 all have considerably larger sidewalls than road cars.
They will reduce road noise and give you a slightly smoother ride.
I do agree with 509 that it would look quite weird on an IS. rather than looking for tall tires you can look for ones that are less aggressive tread patterns/compounds. Tirerack gives reviews on road and noise comfort
Reply
Old Sep 22, 2007 | 09:35 PM
  #4  
supa_89's Avatar
supa_89
Thread Starter
Rookie
 
Joined: Sep 2007
Posts: 81
Likes: 0
From: NJ
Default

Thanks guys really appreciate the feedback, but honestly my concern is just about the ride, I dont care how it looks and am not one to be speeding thats why I bought the 250, so would I be able to fit 215/50/18 on my IS 250AWD without touching or rubbing?
Reply
Old Sep 22, 2007 | 10:15 PM
  #5  
FiveOhNine's Avatar
FiveOhNine
Lexus Champion
 
Joined: Jun 2007
Posts: 1,674
Likes: 0
From: Dark side of the moon
Default

Originally Posted by Namir
larger sidewalls won't necessarily affect performance, Nascar Indy Forumla 1 all have considerably larger sidewalls than road cars.
They will reduce road noise and give you a slightly smoother ride.
I do agree with 509 that it would look quite weird on an IS. rather than looking for tall tires you can look for ones that are less aggressive tread patterns/compounds. Tirerack gives reviews on road and noise comfort
Ok, let me rephrase:

Tire A and Tire B, both same composition, weight, and indistinguishable apart from the difference in profile.

The higher profile tire will decrease performance in cornering and acceleration due to decrease in the lateral and torsional rigidity respectively.

Edit: My guess is that high performance racing tires, as in those you mentioned are set up so as to decrease rotational diameter under high torsional rigidity situations (i.e. rapid acceleration) which 'spreads out' the rubber horizontally to increase the contact patch.

Last edited by FiveOhNine; Sep 22, 2007 at 10:20 PM.
Reply
Old Sep 23, 2007 | 07:25 AM
  #6  
BounceNY's Avatar
BounceNY
Lexus Test Driver
iTrader: (9)
 
Joined: Apr 2006
Posts: 1,068
Likes: 0
From: VA
Default

with the tire sizes u posted, the odometer will be affected. Check out some online tire size calculators which will help u decide on the correct size for the car. (1010 tire website has good calculators).
Reply
Old Sep 23, 2007 | 08:11 AM
  #7  
Bichon's Avatar
Bichon
CL Community Team
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2005
Posts: 5,722
Likes: 347
From: NJ
Default

Originally Posted by supa_89
Thanks guys really appreciate the feedback, but honestly my concern is just about the ride, I dont care how it looks and am not one to be speeding thats why I bought the 250, so would I be able to fit 215/50/18 on my IS 250AWD without touching or rubbing?
If your main concern is ride quality, why are you changing to an 18" wheel?
Reply
Old Sep 23, 2007 | 09:29 AM
  #8  
is4fsr's Avatar
is4fsr
Lead Lap
 
Joined: Feb 2007
Posts: 583
Likes: 1
From: CA
Default

The 215/50/18 should not be a problem as long as you have the correct offset. But if you want to improve ride quality keep the 17" and go for a larger sidewall but it may affect your speedo. you can have your speedo recalibrated then. With regards to going to 18" you will end up w/ smaller sidewall to maintain OD. Smaller sidewall means less tire play thus stiffer = bad ride quality.

with your current set up 225/45/17, your tire sidewall is 4 in, OD 25 in
with 215/50/18, the sidewall will be 4.25 in, OD 26.5 in
so w/ bigger OD you have to recalibrate your speedo.
if you don't mind having your speedo recalibrated and also improve the ride quality, keep the 17" and go for larger sidewall.
current set up 225/45/17 sidewall = 3.99, OD = 24.97
comparison 215/55/17 sidewall = 4.66, OD = 26.31
215/50/18 sidewall = 4.23, OD = 26.46
215/55/17 and 215/50/18 almost the same OD but look at the side wall
4.66 in vs 4.23 in
Reply
ClubLexus Stories

Celebrating Lexus & Toyota from Around the Globe

story-0

2026 Lexus IS 350 F Sport Review: The Last of Its Kind Still Rocks

 Michael S. Palmer
story-1

Top 10 Most Confusing Things Lexus Has Ever Done!

 Joe Kucinski
story-2

2026 Lexus ES Review: Lexus Re-Embraces Founding Principles

 Michael S. Palmer
story-3

10 Lexus Bargains That are Cheaper Than a New Toyota RAV4

 Joe Kucinski
story-4

8 Weirdest Things Lexus Has Ever Built

 Verdad Gallardo
story-5

10 Lexus Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-6

8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

 Michael S. Palmer
story-7

10 Best Lexus Models No One Remembers

 Joe Kucinski
story-8

TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

 Michael S. Palmer
story-9

Top 10 Lexus & Toyotas to Drive Before You Die!

 Joe Kucinski
Old Sep 23, 2007 | 09:44 AM
  #9  
lobuxracer's Avatar
lobuxracer
Tech Resource
15 Year Member
Liked
Loved
Community Favorite
iTrader: (2)
 
Joined: Jul 2006
Posts: 23,084
Likes: 4,752
From: Georgia
Default

1. Your speedo cannot be recalibrated. It isn't possible without a software change in the skid control computer or an intercept device in the speed signal generated by the skid control computer. However, this also affect the ECM's decisions about shift points, so it may have seriously painful unintended consequences. If you change to anything you've listed, you will be going faster than indicated and showing less mileage than actually traveled.

2. If you want better ride quality by adding sidewall, stick with the 17s and go narrower on the stock rims. 205/50/17 would add sidewall but not affect your speedometer/odometer.

3. Going to 18" wheels makes everything worse, not better.
Reply
Old Sep 23, 2007 | 04:14 PM
  #10  
supa_89's Avatar
supa_89
Thread Starter
Rookie
 
Joined: Sep 2007
Posts: 81
Likes: 0
From: NJ
Default

Thanks alot guys..definitely learnt something here..
Reply
Old Sep 23, 2007 | 04:33 PM
  #11  
is4fsr's Avatar
is4fsr
Lead Lap
 
Joined: Feb 2007
Posts: 583
Likes: 1
From: CA
Default

I did not know our ISs speedo can not be recalibrated. Thank for the info, Lobux.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
toup
LS - 3rd Gen (2001-2006)
5
Aug 2, 2012 02:44 PM
Options2k
SC430 - 2nd Gen (2001-2010)
16
Mar 19, 2010 09:13 AM
consult350
IS - 2nd Gen (2006-2013)
20
Oct 14, 2005 10:57 AM
jbee
Wheels, Tires & Brakes Forum
2
Feb 23, 2005 08:29 AM
Higuma
Wheels, Tires & Brakes Forum
7
Jul 22, 2003 12:56 PM




All times are GMT -7. The time now is 06:35 PM.

story-0
2026 Lexus IS 350 F Sport Review: The Last of Its Kind Still Rocks

Slideshow: the 2026 IS 350 isn't all that new, and that's why we love it!

By Michael S. Palmer | 2026-06-04 14:35:23


VIEW MORE
story-1
Top 10 Most Confusing Things Lexus Has Ever Done!

Slideshow: 10 most confusing things Lexus has ever done.

By Joe Kucinski | 2026-06-04 09:40:55


VIEW MORE
story-2
2026 Lexus ES Review: Lexus Re-Embraces Founding Principles

Slideshow: Our First-Drive Review of the 2026 Lexus ES!

By Michael S. Palmer | 2026-05-29 20:30:16


VIEW MORE
story-3
10 Lexus Bargains That are Cheaper Than a New Toyota RAV4

Slideshow: 10 Lexus bargain that are cheaper than a new Toyota.

By Joe Kucinski | 2026-05-20 10:28:20


VIEW MORE
story-4
8 Weirdest Things Lexus Has Ever Built

Slideshow: From hoverboards to luxury yachts, these are the strangest projects Lexus has ever attached its badge to.

By Verdad Gallardo | 2026-05-16 11:34:36


VIEW MORE
story-5
10 Lexus Designs That Have Aged Like Fine Wine

Slideshow: Some luxury cars chase trends, but these Lexus models look better now than they did when they first rolled into showrooms.

By Verdad Gallardo | 2026-05-06 17:58:29


VIEW MORE
story-6
8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!

Slideshow: How to Get the Best Fuel Economy with a Hybrid and Plug-In Hybrid!

By Michael S. Palmer | 2026-05-05 20:54:44


VIEW MORE
story-7
10 Best Lexus Models No One Remembers

Slideshow: 10 best Lexus models no one remembers.

By Joe Kucinski | 2026-05-05 17:33:28


VIEW MORE
story-8
TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing

Slideshow: diving into 4Runner TRD Off-Road Premium's pricing, performance, fuel economy, features, and amenities!

By Michael S. Palmer | 2026-04-23 13:09:18


VIEW MORE
story-9
Top 10 Lexus & Toyotas to Drive Before You Die!

Slideshow: the 10 Lexus and Toyota vehicles you need to drive before you die.

By Joe Kucinski | 2026-04-23 10:34:24


VIEW MORE