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

Tire/Load Rating - safety question

Thread Tools
 
Search this Thread
 
Old 09-11-09, 08:27 PM
  #1  
mdgrwl
Lexus Champion
Thread Starter
iTrader: (7)
 
mdgrwl's Avatar
 
Join Date: Feb 2009
Location: NJ
Posts: 1,871
Likes: 0
Received 1 Like on 1 Post
Unhappy Tire/Load Rating - safety question

right now I'm running Toyo Proxes 4 225/35/19 in the front, the load rating is 88. - and 245/35/19 in the rear with 93 load rating.

in short, is this okay? any safetey issues here?

I've been driving on them for the past 3 months, no issues so far but as these tires age, will that lower 88 front load rating cause something really bad to happen? possible blow out?

I see some people running 215/35/19's up front for that SUPER stretch and of course the load rating on those is even lower... really tho, are we making a big mistake and is super risky?

or in all reality its just fine?

I don't know much about load ratings....
Old 09-11-09, 08:29 PM
  #2  
mikez
Lexus Champion
 
mikez's Avatar
 
Join Date: Jan 2008
Location: NJ
Posts: 3,906
Likes: 0
Received 5 Likes on 5 Posts
Default

I think as long as its higher than OEM it should be okay.

But the fact that its stretched, then the fact that the tires are being rolled on its sidewalls is risky too.

But hey, gotta pay to play right? Some times even if it means being endangered lol
Old 09-11-09, 08:38 PM
  #3  
mdgrwl
Lexus Champion
Thread Starter
iTrader: (7)
 
mdgrwl's Avatar
 
Join Date: Feb 2009
Location: NJ
Posts: 1,871
Likes: 0
Received 1 Like on 1 Post
Default

OEM states minimum should be 89 load rating in the front....
Old 09-11-09, 09:06 PM
  #4  
mikez
Lexus Champion
 
mikez's Avatar
 
Join Date: Jan 2008
Location: NJ
Posts: 3,906
Likes: 0
Received 5 Likes on 5 Posts
Default

You best be on a serious diet

From an engineering stand point, usually things are designed with (what I was taught), a safety factor of 2 or more. Meaning if it says it needs 100lbs of support, in actuality it only needs 50lbs of support, 100lbs to be safe so you wont ever be dumb enough to give it less than 50lbs.

Then again it depends, some items are unable to have a large degree of safety, so I am not too sure to be honest.
Old 09-11-09, 10:56 PM
  #5  
gdcheng
Driver
iTrader: (2)
 
gdcheng's Avatar
 
Join Date: May 2006
Location: CA
Posts: 113
Received 3 Likes on 3 Posts
Default

I think you will be ok. They rate tires on the conservative side so with a load rating of only 1 under what the OEM recommends, you should be fine.
Old 09-12-09, 06:11 AM
  #6  
HKS350
Lexus Champion
iTrader: (4)
 
HKS350's Avatar
 
Join Date: Apr 2006
Location: North Carolina
Posts: 1,704
Likes: 0
Received 10 Likes on 10 Posts
Default

Saftey not a big deal, but you will wear through the tire faster.
Old 09-12-09, 08:01 AM
  #7  
ChrISF
Lexus Champion
 
ChrISF's Avatar
 
Join Date: Oct 2007
Location: Baltimore
Posts: 2,902
Received 12 Likes on 6 Posts
Default

HKS350, your sig is dope.
Old 09-12-09, 08:27 AM
  #8  
15951
Lexus Test Driver
 
15951's Avatar
 
Join Date: Jun 2006
Location: FL
Posts: 1,188
Likes: 0
Received 6 Likes on 3 Posts
Default

The OEM Dunlops and Bridgestones are 88 front, 95 rear.

If you're stretching tires, the manufacturer's load rating is practically worthless, because you're not using them in the way they were intended. The numbers on the sidewall are the least of your worries in this instance.

By the way, load rating 88 = 1,235 pounds/tire, and 95 = 1,521 pounds/tire. Curb weight (unloaded) of the IS350 is 3,527.4 lbs, so that gives you about 1,985 pounds of people and cargo to max out the OEM tires. I can't imagine what the ride would be like with that kind of weight added...you guys could probably skip lowering the car at that point.

Last edited by 15951; 09-12-09 at 08:33 AM.
Old 09-12-09, 02:55 PM
  #9  
mdgrwl
Lexus Champion
Thread Starter
iTrader: (7)
 
mdgrwl's Avatar
 
Join Date: Feb 2009
Location: NJ
Posts: 1,871
Likes: 0
Received 1 Like on 1 Post
Default

^ No this post actually makes sense. What do you think about the slight 'stretch' though? Actually, according to Toyo's website I can use their 225/35/19 tire on a wheel anywhere from 7.5 to 9.0 inches. I'm running it on an 8.5. So I'm not even maxing out their recommendations....

But anyway, does 'stretching' a tire decrease its load rating? I would imagine it can't help...
Old 09-12-09, 07:25 PM
  #10  
15951
Lexus Test Driver
 
15951's Avatar
 
Join Date: Jun 2006
Location: FL
Posts: 1,188
Likes: 0
Received 6 Likes on 3 Posts
Default

According to other sites (and good sense), tire stretching will result in:

- decreased load ability for each tire
- decreased traction
- increased heat
- increased wear

If I ever drove a car that had this done, I sure as hell wouldn't ever take it into triple digits.

Other than doing this for appearance, I see zero benefit. Cost/benefit analysis results in "fail".
Old 09-13-09, 12:16 AM
  #11  
VF84
Pole Position
 
VF84's Avatar
 
Join Date: Jun 2007
Location: CA
Posts: 296
Likes: 0
Received 0 Likes on 0 Posts
Default

european regulations created the stretched look as tire tread is supposed to "inside" the fender. so all those ridiculously wide and/or deep dish rims need stretched tires

oem 225-40-18 on the front looks rather stretched to me. anyone else notice that?

and i'm not entirely sold on the decreased traction part. there are some ppl who run slightly stretched tires to reduce flex during cornering for autox
Old 09-13-09, 08:25 AM
  #12  
mdgrwl
Lexus Champion
Thread Starter
iTrader: (7)
 
mdgrwl's Avatar
 
Join Date: Feb 2009
Location: NJ
Posts: 1,871
Likes: 0
Received 1 Like on 1 Post
Default

well then we get into whats a 'stretch'? 'stretch' based on the way the tire 'LOOKS' or if its within the tire manufacturer's rim width guidlines.

according to ToyoTires, these size tires are 'approved' to fit on these rid width's:

225/35/19 - 7.5" to 9.0"
235/35/19 - 8.0" to 9.5"
255/35/19 - 8.5" to 10.0"

anyone visually looking at a 225/35/19 on a 9.0" wide rim would say 'wow, thats stretched' - but its still within mfr specs.
Old 09-13-09, 02:58 PM
  #13  
mdgrwl
Lexus Champion
Thread Starter
iTrader: (7)
 
mdgrwl's Avatar
 
Join Date: Feb 2009
Location: NJ
Posts: 1,871
Likes: 0
Received 1 Like on 1 Post
Default

eh, i'm fine.... my tires can handle 5,336 lbs total and the IS350 weights 3,500 so that give me 1800 lbs of fat people to put in my car before I even have to start to worry about failure....
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JDW379
GS - 4th Gen (2013-2020)
1
07-28-14 11:26 AM
BS ISF
IS - 2nd Gen (2006-2013)
5
05-23-12 01:56 PM
poorbong
GS - 3rd Gen (2006-2011)
2
04-17-09 10:27 PM
sam430
GS - 2nd Gen (1998-2005)
6
01-05-09 12:50 PM
gc86
IS - 2nd Gen (2006-2013)
3
12-13-08 10:10 PM



Quick Reply: Tire/Load Rating - safety question



All times are GMT -7. The time now is 03:46 AM.