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which tire is better?

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Technically speaking, 235's will fit on a 7 inch wide wheel, but it's not safe and not recommended. Stick with 215's or 225's.
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Exactly...what's 10mm's? Local Discount Tire Man ***Tech Note***The stiffer the sidewall, the more issues that could arise. H-rated...no biggie...Z(sub Y-W)-rated...you could actually start to split the shoulder/sidewall area of the tire! tata
 

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Discussion Starter #22
Exactly...what's 10mm's? Local Discount Tire Man ***Tech Note***The stiffer the sidewall, the more issues that could arise. H-rated...no biggie...Z(sub Y-W)-rated...you could actually start to split the shoulder/sidewall area of the tire! tata
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wow - sounds pseudo scary - any pics of what this looks like when it happens?
 

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there's an "rim width range" that you'll see for any specs on tires. for 225/50 for instance, it'll say "6-8". it'll perform to the fullest at the median of that range, so 7" in this case. 235/45 is 7.5-9" range, the middle ground being an 8" wheel.

235 should NOT be on a 7 inch wide wheel, period.
 

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these guys like to talk in extremes. :D

under no normal day-to-day driving is this setup not safe ;)
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I guess you would know better than ALL of the tire industry on this issue. :sarc:

What would possibly be my agenda other than providing information to ensure his/her safety?

wow - sounds pseudo scary - any pics of what this looks like when it happens?[/b]
Note what is says under Possible Conditions, last entry:
[attachmentid=12070]
 

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Discussion Starter #25
Note what is says under Possible Conditions, last entry:
[attachmentid=12070]
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interesting... does this happen under 'normal' dtd driving? or auto-x stuff?
 

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there's an "rim width range" that you'll see for any specs on tires. for 225/50 for instance, it'll say "6-8". it'll perform to the fullest at the median of that range, so 7" in this case. 235/45 is 7.5-9" range, the middle ground being an 8" wheel.

235 should NOT be on a 7 inch wide wheel, period.
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ONLY BECAUSE OF THE WHAT IF's!!

Anytime...that bead grooving pic actually looks like the clip of a wheel weight just being pressed in!
 

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Discussion Starter #27
ONLY BECAUSE OF THE WHAT IF's!!

Anytime...that bead grooving pic actually looks like the clip of a wheel weight just being pressed in!
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hmm - now that you mention it, the 'abrasion' looks like the wheel weight issue... fortunately, our wheels use the sticky weights and not the rim clips :)
 

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And that showcases exactly why its a bad idea to put wide rubber on thin wheels. Look at the sidewall in photo 2. Its actually bending in like so.

/

\


This shows you how the sidewall is getting absolutely zero support from the wheel. Instead of the wheel pressing into the shoulder, and reinforcing its stability, its flopping around so much it has to bend in to get any type of support.

This is not only awful for lateral stability (you'll have to run 40 psi+ just to keep the sidewalls from rolling over), but you can see exactly why its easier for the tire to seperate from the wheel.

Here's an example of the opposite situation. This is a 225/45/17 on a 17x8.



Here you can see the width of the wheel is actually pushing the sidewall out and reinforcing it. Now the angle of the sidewall is significantly more vertical, and even tilted back in slightly like so

\

/


These are of course exaggerations, but help to illustrate the point.

Another shot.


In the first situation (235/45/17 on a 17x7) the sidewall will fold in on itself in a corner. In the second situation, (225/45/17 on a 17x8), the wheel width stabilizes the sidewall shoulders, and helps them maintain their shape under cornering stresses.

Is it dangerous to put wide rubber on thin wheels? (Past spec). Yup, more so then if you followed manufacturer recommendations. Its quite similar to ignoring the load ratings on the tires. You increase your risk of something bad happening.

Will something bad happen? Probably not. Will the fact it provides less stability, less traction, and is more dangerous stop people from running the tire size? No, people like to do what they want regardless of advice given. Then when something bad happens, they'll just blame it on poor wheel/tire design.
 

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most passenger cars I see on the raod seem to be violating this rule. hence my comment that it should not cause problems in day-2-day driving.

it appears that toyoguy is unhappy with my comments. Sorry. it was not meant to be personal, nor a challenge to ur knowledge.
 

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Discussion Starter #32
And that showcases exactly why its a bad idea to put wide rubber on thin wheels. Look at the sidewall in photo 2. Its actually bending in like so.

/

\
This shows you how the sidewall is getting absolutely zero support from the wheel. Instead of the wheel pressing into the shoulder, and reinforcing its stability, its flopping around so much it has to bend in to get any type of support.

This is not only awful for lateral stability (you'll have to run 40 psi+ just to keep the sidewalls from rolling over), but you can see exactly why its easier for the tire to seperate from the wheel.
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good stuff... considering i have a higher weight load tire now (94W) vs stock -will that help?
 

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it appears that toyoguy is unhappy with my comments. [/b]
Frustration is more like it, chikoo. I just don't understand why people seem to think there are exceptions to these specifications. It's like, "Yeah, I know these manufacturers do all these tests and stuff, but they really don't apply to me." Crossbow hit the nail on the head:

...people like to do what they want regardless of advice given. Then when something bad happens, they'll just blame it on poor wheel/tire design.[/b]
I don't remember reading anywhere that the rim width specifications are for racing. They are for normal day-to-day driving. Racing would only exacerbate the problem.

most passenger cars I see on the raod seem to be violating this rule.[/b]
How could you possibly know this unless you walk around all day with a tire spec guide in your hand and are inspecting tires in parking lots? How would you know the width of a wheel just by looking at it from the outside? I'm not even that good. My experience has been that the vast majority of vehicles on the road are using tire/wheel combos that are within spec. I know this because I'm in tire shops on a daily basis. I see the tires that come off people's cars on a daily basis. The vast majority of vehicles on the road have the factory wheels on them and the vast majority of those vehicles have the factory size on them. I get asked by tire dealers to evaluate tires that have come off cars with problems. And I go through a systematic process of determining probable cause. The people who "violate" specifications are typically the ones who have problems.

Toadster, you might get lucky and nothing bad will happen, but if your tires start to exhibit irregular problems (ie bead grooving/chafing, shoulder cracking or even irregular wear) and you go back to see if they are covered under warranty, you can bank on getting a warranty claim denied because you mounted the tires on non-spec wheels. And higher load ratings have no correlation or effect to compensate for mounting tires on non-spec wheels.

I'm just trying to help you guys from frustration down the road, but you know, it's your car, do what you want. I'm not some tire Nazi who says "do what I say or else!" Just trying to make you guys' lives easier.
 

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no arguments.
this is going nowhere.
What I was trying to explain is that bulging sidewalls like pic#2) is what is see on so many cars. if that is no indication of a violation, I withdraw my comments.
 

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A bulging sidewall doesn't indcate that the tire has exceeded the minimum spec's, but it does indcate that factors other then optimal handling were chosen during the purchase of the tire.

I think you can easily agree that 98% of the automotive population could care less about tire grip and performance.

Their primary concerns are longevity, wear, and noise/comfort. Walking around a parking lot, the general tire you'll see is either OE brands, or the tires pepboys has on sale...every weekend.

The remaining 2% are split into various divisions, depending on auto sport they participate in, or what car shows they try to represent in.
 

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Discussion Starter #38
Looks GREAT to me!
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thanks!! and to be honest, i am VERY surprised at how 'plush' these tires ride... VERY smooth, and i've put about 300 miles on them so far... turns are MUCH more predictable and the car feels much more nimble now that i actually have some tread down there :D

tomorrow i'll pack on about 400 miles to the bay area and back...

so far - VERY happy with these tires!
 

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no arguments.
this is going nowhere.
What I was trying to explain is that bulging sidewalls like pic#2) is what is see on so many cars. if that is no indication of a violation, I withdraw my comments.
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Relax, chikoo. We're not arguing, just having a discussion. It's good, b/c perception doesn't always equal reality. If it's bulging sidewalls you're referring to, then taller profile tires, such as 65, 70 & 75 (which are common among most passenger cars and light trucks) tend to have the bulge in the sidewall because there is more surface area and the sidewalls are more flexible. Lower profile tires don't bulge as much b/c they are stiffer and the rim width affects performance much more due to the fact that the rim width changes the angle of the sidewall to the road much more prominently in shorter sidewalls. Makes sense?

For example, this standard passenger tire has a relatively tall sidewall, thus the curvature to the sidewall profile, even though it is mounted on an approved width rim:


Notice the nearly vertical sidewall on this low profile performance tire:


Mounting a tire like this on too narrow of a wheel more drastically affects performance and creates more chances for problems with bead or shoulder cracking. A narrow wheel would "pinch" the sidewalls inward, putting them at a less-than-optimum angle to the road. Hope that explains where I'm coming from.

Again, this is not a "can of worms," guys. The reason I bring this stuff up is to help you get the best performance, the longest life and the fewest problems out of your tires and to help you understand/diagnose why sometimes things go wrong.
 

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thanks!! and to be honest, i am VERY surprised at how 'plush' these tires ride... VERY smooth, and i've put about 300 miles on them so far... turns are MUCH more predictable and the car feels much more nimble now that i actually have some tread down there :D

tomorrow i'll pack on about 400 miles to the bay area and back...

so far - VERY happy with these tires!
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the plushness very much has to do with your rim width :)
 
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