TimW

iTrader: (6)

another flame thread? he already said he was kidding about the 275.

I assume you want to argue with him on this, in that case, I'll step out... just keep it on topic and dont get personal.

y2kse

iTrader: (1)

No Tim. This has nothing to do with the person who was talking about the 275s. What I'm waiting for is someone to come up with a manufacturer of 235/45R17 tires who is willing to stipulate in writing that it's OK to mount those tires on 7" wide rims. Maybe . . . just maybe . . . such a manufacturer exists. And by provoking a few people, maybe . . . just maybe . . . I'll get them to actually try to find that manufacturer in an attempt to prove me wrong. If they can find one, I'm sure they'll think they've put one over on me. But just between you and me, I'll still be the winner. You see, no one would like to run 235/45R17 tires on their OEM rims more than I would. So even if I lose, I win!

Beautiful, ain't it?

PS: Here's a little trump card I've been saving. I knew if I played this one, there would be hell to pay. But I'm more interested in getting to the truth than in making myself look good. So despite the fact that I'll probably be flamed mercilessly, I'll play it now.

This is from the Tirerack.com web site:

" . . . some vehicle manufacturers and tire companies have permitted rim widths that are not within the tire's original approved rim width range. For example: BMW has combined 235/40R17 sized tires on 17x7.5" rims (which are 0.5" less than the narrowest 8.0" wide rim listed for the size) on certain M3 models; and Chevrolet has combined P255/50R16 sized tires on optional 16x9.5" rims (which are 0.5" wider than the 9.0" wide rim now listed for the size) on certain Corvette models. While these applications have received the approval of the vehicle and tire manufacturers, staying within the approved rim width range helps assure that the tire's internal stresses are within its design parameters."

Source: http://www.tirerack.com/tires/tirete...#rimwidthrange

So the possibility of locating a tire manufacturer willing to stipulate that their 235/45R17 tires can safely be mounted on 7" wide rims isn't outside the realm of possibility. But I'm not going to change my position until that manufacturer can be found.

Fire away, gentlemen.

TimW

iTrader: (6)

I think I will start bugging Kumho daily about it. I'd really like to see the 712 in our size. They'd sell a ton of them.

y2kse

iTrader: (1)

From your lips to God's ears, my friend. But if Kumho won't do that, a simple written statement from them stipulating that their 235/45R17 tires are OK to run on 7" wide rims would get the job done. I just want to be able to cover my a$$.

nddst

Unless they're driving next to ME on the highway!

Norm Peterson

Guys, this tire size and rim width thing is an engineering problem. No matter how badly you might wish otherwise, acceptability does not rely on appearance or the physical feat of successfully getting the tires mounted and inflated. Rim designs and contours can disguise how much "bulge" actually exists and, at the other extreme, I've seen some truly scary combinations.

What I'm waiting for is a clearly written, engineering evaluation regarding the installation of overly wide tires on the OE 17 x 7's. Preferably from somebody with some grasp of tire structure and who has personally mounted a few tires and knows what this looks like up close. Then we can all talk details.

Like y2kse, I'd like to see written evidence from any tire mfr that considers the 235/45 on 17 x 7 an acceptable combination. I fully expect that such approval would be restricted to only certain tire models, so don't get the idea that if one tire mfr says it's OK that you just got blanket approval to use anybody's 235/45 on the OE rims. Individual tire models vary slightly in their dimensions, so I can see the possibility of a "narrow" 235/45 getting the OK from its mfr to go on a 7" rim where a "wide" one would not.

Norm

srbarnes4ever

Does the 7" apply regardless of rim diameter? I'm looking at some Enkei CDR9s over on tires.com and they are spec'd at 18" x 7" so does that mean I'm still unable to put a 235/45 or 235/40 tire on this rim? Thanks in advance!

y2kse

iTrader: (1)

In keeping with the general principle that you should never take anyone's word for tire specifications other than the manufacturer's, let's use your question to help you and others figure out how to acquire this information for yourselves.

First, go back to my post on page 3 of the FAQs and take each factor I listed one at a time. Remember, this is the information you need:

1) Overall diameter - stay within 3% of the OEM tire/rim diameter.

2) Rim width - do not exceed the tire manufacturer's specifications.

3) Speed rating - do not select a tire with a speed rating less than the speed rating of your OEM tires. (The speed rating of your OEM tires is located on page 10-9 of your owners manual.)

4) Load rating - do not select a tire with a load rating less than the load rating of your OEM tires. (The load rating of your OEM tires is located on page 10-9 of your owners manual.)

Begin by using the tire size calculator in the FAQ to determine which tire would provide the best overall fit from a diameter perspective. Then go to the web site of the tire manufacturer for the other specifications. Use an internet search engine to locate the manufacturer's web site.

When you've figured out the answer to your rim width question, come back and let us know what you found out. Then tell us about the tire size you selected in terms of its overall diameter, speed rating and load rating. If you need help, send me an e-mail at bld522@yahoo.com and I'll gladly walk you through it. I'll also keep our communications confidential.

Ready . . . set . . . GO!

y2kse

iTrader: (1)

Excellent points, Norm. Thanks.

srbarnes4ever

Without going through all the old links and posts, I believe the answer will be that rim width is the key to what size tire can be mounted, thus I would be outside of tire specs to mount a 235/40 or 235/45 tire onto an 18 x 7 rim. The dunlop page says the acceptable rim width must be at least 85% of a sub 50 series tire and in this case it is in the 75% range which is too low....Looks like Enkei CDR9s are off my list. Tell me if I've got it all screwed up though, and thanks as always!

srbarnes4ever

OK I've confused myself on this one now. Based on the rim width required to be 85% of the section width on a sub 50 series tire,then even a 235/45 would not be acceptable for use on a 7.5" rim for Dunlop tires because the rim would only be 81% of section width. Is this correct Y2kse? Teach me please!

y2kse

iTrader: (1)

Man, you've got me there sbarnes4ever. I'm not an engineer. My advice to you is to follow the manufacturer's specifications . . . period. You shouldn't go wrong if you do that. And if you do go wrong, you've always got the manufacturer to fall back on.

BTW, you stated that rim width was the key in deciding what tire size could be mounted on a given rim. I'd argue that load rating is an even bigger key. But there are several factors that have to be considered when selecting a tire/rim combination other than the OEM tire/rim combination. And failure to pay attention to any one of them could have serious consequences.

Norm Peterson

That's the conclusion that the technical side of this discussion strongly supports. Use it in lieu of specific mfr data to the contrary.

What you're trying to do is maintain the curvature and flexing of the tire's sidewall within acceptable limits, so given that a 235/45 tire (or the 235/40) has the same cross-section dimensions regardless of the wheel diameter, the same rim width requirements will still apply.

Ultimately, it would be up to the tire mfr to determine whether or not the extra inch of wheel diameter makes it possible to justify mounting those sizes on the slightly narrower rim. Or whether that extra inch makes the 7.5" minimum width less negotiable.

Norm

srbarnes4ever

Thanks Y2kse, I didn't mean to brush off the load rating as I definitely won't go lower than OE on that. I just checked Dunlops perf. tire section and Bridgestone's and Dunlop does have a minimum of 8" rim width on all 235/40 or 235/45 tires so I guess they are following their own recommendations. bridgestone has several 234/45s that are OK for 7.5" rim widths so you're certainly right in that EACH tire manufacturer may have unique requirements based on their engineering design specs.

y2kse

iTrader: (1)

Keep in mind that manufacturers don't set their own specifications for certain parameters, including rim width. Those specifications are established by standards organizations. The governing standards organization in the United States is the Tire and Rim Association of America (T&RA). Failure to conform to their specifications creates an assumption of liability no tire manufacturer is willing to accept (with a few notable exceptions such as the M3 and Corvette situations I referred to previously).

Norm makes an excellent point. Some 235/45R17 tires are "narrower" than others, and you cannot tell which ones they are by looking at how they fit on the rim. So without knowing in advance what the specific design parameters are, it's impossible to determine which 235/45R17 tires are the "safest" to mount on 7" rims. But I sure would like to know which tire manufacturer BMW selected when they decided to mount 235/40R17s on the M3s 7.5" wide rims . . .

srbarnes4ever

Well I'm a bit confused again. So the tire manufacturers themselves DO NOT set this rim width spec.? If not then how is Dunlop saying one thing and Bridgestone another in this case? I'll do some google searching on tire and rim association and see what I come up with.

y2kse

iTrader: (1)

I don't believe they are saying something different, srbarnes4ever. Do their rim width specifications differ for the 235/45R17 tires they manufacture?

BTW, I don't believe the T&RA has a web site. I suspect they don't need one. But here's how you get in touch with them if you're interested:

http://www.tirestyres.com/assn/tara.html

And you understand that the "safest" 235/45R17 tire that you can find is still unsafe to mount on a 7" wide rim according to the manufacturer of the tire. I believe the point Norm was trying to make is that if you must do something unsafe, it makes sense to do the least unsafe thing you possibly can . . . assuming you can figure out what that is, of course. Correct me if I'm wrong about that, Norm.

y2kse

iTrader: (1)

Could this be a clue?

http://www.bmw-tokyo.co.jp/after/b_0322.html

MAX2000JP

What year is the M3??? Most E36 M3's run on Pilots(Sport and MXX4???). My moms got a 330i Sport with Dunlop 8080Es on it. I think i am gonna check the rim width when I get home.

BuddyWh

I know this thread isn't really about it... but I have to take issue with the speed rating suggestion. One should feel free to select a tire with a minimum speed rating that is consistent with the way they actually drive their car.

If you never exceed 100 mph, and do not plan on it, there is no reason to artificially limit yourself to a U or V rated tire. Unless, of course, you like other qualities of such a tire and there are many to like since manufacturers typically submit top-of-the line tires for testing and certification to higher speed ratings.

IMO the only reason an OEM like Nissan establishes such a criteria is to limit their liability exposure because they have no idea how I will drive my car, and it is capable of 130+ mph. But I do have an idea how I will use my vehicle, and so do most other users (well, those without teenagers perhaps).

And, besides, speed ratings are so highly over-rated anyhow: they are only meaningful when a tire is new and undamaged. One should never think their Z-rated tire is safe even at 100 MPH if it has ever gone flat with the car's weight on it, had a leak repaired, struck a bump, has a sidewall bulge. Nor, even, if it has more than a few thousand miles wear because age, sun and heat change the rubber compounds.

And I would add to the load rating consideration that just observing the OEM's recommendation is not always sufficient. You should increase it if you've modded the suspension to carry heavy loads with the expectation of actually doing so. Probably not pertinent to Max owners, but I imagine not just a few are also truck/SUV owners who've added trailer packages and/or after market heavy duty springs increasing load capacity. Please consider that too!

Buddywh

y2kse

iTrader: (1)

Excellent points on both speed rating and load rating, BuddyWh. My only concern regarding speed rating is whether or not you can always determine who will and will not drive your vehicle. If you KNOW that no one will ever drive it but you, then you can safely lower the speed rating to the highest speed at which you will ever drive. If you cannot, then it's probably a good idea to stick with the OEM speed rating. And your concerns about the effects of wear and repairs also argue in favor of higher speed ratings at the outset. After all, if a Z-rated tire with a lot of wear or repairs cannot be trusted at 100 mph, can an H-rated tire with the same wear or repairs be trusted at 70 mph?

And yes, load rating should be increased if it's anticipated that the vehicle will be heavily loaded. BTW, I suspect that load rating is the most dangerously overlooked factor in tire upsizing, particularly when the rim is upsized as well. Case in point:

http://forums.maxima.org/showthread.php?threadid=116540

srbarnes4ever

[QUOTE]Originally posted by y2kse
[B]
I don't believe they are saying something different, srbarnes4ever. Do their rim width specifications differ for the 235/45R17 tires they manufacture?

Thanks for the link, I'll check it later today. To answer your question above though, yes. Dunlop says that for a 235/45/17 that rim width per their charts is 8" while Bridgestone says 7.5 for the same. Let me run back to their sites and double check that my vision isn't screwed up.

y2kse

iTrader: (1)

[QUOTE]Originally posted by srbarnes4ever
[B]Yes. I've also noticed that on occasion, srbarnes4ever. My suspicion is that a manufacturer doesn't have a problem issuing a specification that's more conservative than the T&RA guidelines. And if you contact the manufacturer with the more conservative specification and point out to them that the T&RA guidelines are more liberal than their spec, you might get them to conform to the guidelines rather than insist on maintaining the spec. But that's just a guess on my part.

My only experience in dealing with specification discrepancies is when the manufacturers' specifications are more liberal than the T&RA guidelines. In every instance where I brought this to the manufacturers' attention, they changed their specifications to bring them into conformance with the guidelines.

Blackgums100

I always thought speed rating was relevant, it is not just regarding top speed but you have to factor in taking turns also. My understanding is you have to use percentages. So if you decide to use say a T rated tire you should not assume you could take a turn as fast as say with a Z rated tire.

y2kse

iTrader: (1)

Good point, Blackgums100. After you posted, I found the following information on a tire dealer's web site. I think it speaks to your point:

"Speed rating is a government regulated measurement which is given to a tire for meeting minimum standards for reaching and sustaining certain speeds. Generally a higher speed rated tire will have better handling. Whalen Tire does not recommend downgrading the speed rating on your vehicle. Doing so may result in undesired handling qualities. Your vehicle was designed to use a minimum speed rated tire to handle properly. Installing a higher speed rated tire will help the handling of your vehicle especially in cornering. Make sure however that you do not mix different speed rated tires on the same vehicle as this will cause handling problems."

Source: http://www.whalentire.com/faqs.cfm#speed

Norm Peterson

The point I was trying to make was that if a tire mfr was going to OK a tire/wheel combination outside the usual range, as is apparently the case in the above BMW and Corvette examples, they would do so in the least adverse manner, and with access to far more information than most if not all members of this forum have. Worth noting is that in both of the above cases the "violation" is only to the next half inch.

The specific tire's actual design section width and profile would be kept in mind. i.e. is the specific 235/45 tire really a 231/47? If so, that specific tire would certainly be more likely to get an OK on 7" than would a 239/43. Rim flange profile is another applicable parameter, as it has some effect on the shape of the tire carcass in the bead region.

I did open up the concept that tire diameter might have some effect, but qualified that by stating that I don't know which way that would influence the matter. Haven't tried to figure it out yet either.

Noted in another post above is the way in which the "measuring rim width" is established. Tolerance either way is permitted, but you'll probably notice that tires are usually permitted on wheels more wider [than the measuring rim] than narrower. IOW, given an 8" measuring rim width, the range of acceptable rim widths might fall between ½" narrower and 1" wider. My guess is that with the wider rim the flex component of tire fatigue effects drops (due to more effective support from the wheel) and partially offsets the stress added from stretching the beads further apart. With a narrow rim there is increased fatigue due to increased flex instead, so the total goes up both from the flex and from pinching the bead inward. .

I've had some thoughts about measuring rim width vs percentage of tire section width, namely that there are only two specified %ages to cover at least 10 tire profiles over a 2.5 to 1 range of profile. A good case could be worked up for a few more % of section width brackets. Not for me to decide though, only to make stray comments about . . .

Norm

AznWontonboy

heres something else to keep in mind. A lot of aftermarket wheel packages use 205's or 215s on 7" rims.. so..

doublea

iTrader: (7)

I have been running Ecsta Supra 712 235-40-17 on TMW GTV 17 x 7" for almost a month and my ride is very good, no bulge, it's a perfect fit, no matter what anyone can say. Oh btw the 235-40-17 is not as wide as 235-45-17 make the calculation yourself.

A Y-Pipe is not street legal and many of us have one and no one give us **** about it, same thing for other mods, so I say use your good sense and you will live long, because a mods is a mods.

Here the proof of what I'm saying.

http://community.webshots.com/script...bumID=36218860

Cheers

AA

y2kse

iTrader: (1)

Specifications for the 235/40R17 Kumho ECSTA 712:

Minimum rim width = 8"

Load rating = 90

(Look for yourself: http://www.tirerack.com/tires/Spec.j...CSTA+Supra+712)

Speedometer error compared to 225/50R17 = 5.6%

Anyone else want to follow in doublea's footsteps . . . or should I say, tire tracks?

Never underestimate the power of denial!

BuddyWh

Sorry, but that statement is so disingenuous it can only have been written by a marketing blurb artist! First of all, implying that speed ratings are a government standard when they aren't... and that's pretty obvious because the majority of tires sold do not have a speed ratings at all!

Read the blurb carefully- only the way speed ratings are measured are regulated (and probably not by the US government except under truth in advertising because speed ratings are a European thing) and from what I have read the measurement process does not consider "handling qualities" in any way. It sounds possible to speed rate a solid steel tire all the way to Z and I'd hate to try a corner on four of those!

And about that magical linkage of speed rating to handling quality... if there were such a close relationship then would it not follow that as a tire loses it's speed rating in service, as all tires must, then it must also loose all it's handling qualities and become no better than a Pep Boys weekly special which also has no speed rating! I don't think so!

I'm not saying speed ratings aren't relevant and a good indicator of tire quality as they obviously are... for now. I'm just saying that this marketing drivel is not proof of anything except that advertising companies have learned how the internet uses FAQ's... and have subverted the acronym to their own purposes of confusing us with emotion disquised as facts!

BuddyWh

doublea

iTrader: (7)

For the speedometer off by 5.6%, ask me if I care... I didn't denied anything you may have said about manufacturer spec. This is the set-up I have and it's just fine, I dont have a problem with it, so if it ever happend that I have one I will deal with it, you can debate and say whatever you want to inform other that's fine with me, but you dont need to be sarcastic, BTW I didn't buy anything from tirerack, Mr Right.

Good night.

AA

nddst

Anyone running unsafe tire sizes on their maxes, please post here, so I know who to avoid on the roads!

Heh

BuddyWh

Actually... as I read it, any tire with wear and tear doesn't decrease in actual speed rating a little bit it loses it's speed rating entirely, and what's considered wear and tear sounds pretty light to me. And nebulous... it could be as much as 40,000 miles or 10,000 or 1,000 or 100, you just don't know where that point is. It needs to be considered unsafe at high speeds, and not driven to that point. End of story. Don't drive faster than you'd be comfortable having a blow out at.

Another way to look at it... it is no better than the Pep Boys special we all spurned but was oh so much cheaper. Yet we drive around with it on our cars that are capable of 130+ mph without a thought, naively confident we're safe if I or someone I allow (or don't) wants to punch it up there. Gee golly wow. How silly of me.

The ONLY thing a speed rating is good for is, for now, giving us a clue what a really good tire is. However... I have read that most tires could be rated to U or V territory. Apparently, though, it's not too bright to rate a tire with low profit margin that high and incur the added liability risk. It's a business decision, and I can only hope it stays that way, but as more manufacturers discover a gold mine in high speed ratings I've no doubte they will get flaky handling tires rated into V and U territory.

Finally... check out Goodyear's thoughts on replacing speed rated tires...

"However, if you never drive at speeds near the limits of your speed rated tires, you may choose to replace them with tires having a lesser top speed rating.
..
Speed ratings do not indicate how well a tire handles or corners. They only certify a tire's ability to withstand high speed."

This is their advice to government and police agencies that are replacing their tires. Organizations motivated more by facts than emotion.

Check it out at
http://www.goodyear.com/gov/policetires/speed.html

BuddyWh

y2kse

iTrader: (1)

Thanks, BuddyWh. There seems to be a disparity of opinion in this area. Here's what Dunlop has to say:

"Can I fit replacement tyres with a lower speed rating than the original?

Currently this is not illegal in the UK but it is strongly recommended that tyres should be of at least the same speed rating as those fitted when the vehicle was manufactured. This will help to ensure that they will be adequate for the car’s overall performance including handling, braking and acceleration. In some countries, it is illegal to drive on tyres with a lower limit than the car’s maximum speed capability."

(Source: http://www.driveradviser.com/tyre/faq.shtml#q9)

and

"Never downgrade

Never fit a tyre with a lower speed rating than the vehicle manufacturer’s specifications. Speed, acceleration, braking and cornering have all been taken into consideration for your model of car. If your vehicle is involved in an accident, and is fitted with ‘downgraded’ tyres, your insurance company may refuse to cover you."

(Source: http://www.dunloptyres.co.za/SafetyHints.htm)

Call me silly, but whenever tire manufacturers square off on an issue (as appears to be the case here), I ALWAYS adopt the most conservative position. Under the circumstances, I will not run a tire on my Maxima that has a speed rating less than that of the OEM tire. Others, of course, may do as they please.

y2kse

iTrader: (1)

Sweet dreams.

y2kse

Norm Peterson

I'll stipulate that the actual measured width of a 235/40-17 could be different from that of a 235/45-17 even within the same tire make and model. But in the absence of such information, please demonstrate with some calculations how 235 does not equal 235.

Norm
(Call me Oscar today)

srbarnes4ever

[QUOTE]Originally posted by BuddyWh
[B]

Actually... as I read it, any tire with wear and tear doesn't decrease in actual speed rating a little bit it loses it's speed rating entirely, and what's considered wear and tear sounds pretty light to me. And nebulous... it could be as much as 40,000 miles or 10,000 or 1,000 or 100, you just don't know where that point is. It needs to be considered unsafe at high speeds, and not driven to that point. End of story. Don't drive faster than you'd be comfortable having a blow out at.

I'd like to look into this topic a bit more. Any non-tire manufacturer related sites to browse? My understanding is that a speed rating means the tire has been tested and confirmed to be able to withstand the maximum speed per that rating category for a MINIMUM of 6 consecutive hours! Therefore Z rated tires are supposed to be able to run 150+ for 6 consecutive hours without any failure of tread. The basis of the speed rating would be derived from the chemical breakdown of the tire itself and in theory should not deteriorate over the life of the tread. It makes no sense to me that a tire can be rated Z for example and in 10K miles be a Pep Boys POS. Of course I'm no chemical engineer or tire manufacturer so I could be wrong.

Blackgums100

I now on our stocker 17's the Potenzas were fine up until about 5K then they started to worsen. I researched that Bridgestone actually skipped a process in the manufacturing of the crap stockies that cause it to breakdwon at a drastic rate, shameful f*cks. Were as on say there RE950's, one of their latest, they have added a process which makes it a great tire, long tread life and great traction throughout the treadlife. The majority of the tire company's and auto manufactures should be ashamed of the stock tires they provide.

y2kse

iTrader: (1)

PS: Do you think we should tell doublea that as the aspect ratio decreases, so does sidewall flex, hence the need to mount a tire of a given width with a lower aspect ratio onto a wider rim than a tire with the same width and a higher aspect ratio? Or should we let him prove that to himself the hard way?

PPS: Hey nddst. If you and I are out driving our Maximas one day and you happen to spot doublea's Maxima out in front of you, call me on my cell phone and let me know. I'll line up right behind you!

BuddyWh

[QUOTE]Originally posted by srbarnes4ever
[B]Of course you are right... what I point out is a problem with certifications wherever employed: for instance, an EMT is certified to administer CPR through, say, May the 15th. Does that mean, at 12:01 AM May the 16th anyone he touches instantly dies???? No. But HE IS NO LONGER CERTIFIED and MUST NOT WORK until re-certified.

The problem with speed rated tires is they lose certifications the manufacturer gave us at some nebulous point... we don't know when. And, obviously, there is no practical means to recertify, so how can we rely on it at all.

Rubber absolutely changes chemically and mechanically over the course of the tire's life; ask any chemical engineer (I have). I can tell it myself in how much rougher a tire rides as the rubbers harden and lose resiliency. Even though there is good tread depth handling has degraded and cabin noise is higher (I have dumped a couple sets of Pirelli's for that very reason).

FWIW: the best handling qualities are typically seen in new rubber with low tread depth. In fact it's quite common for racers to buy brand new tires and shave tread. Of course it greatly reduces total tire life... but doesn't it also make sense from a safety perspective if one shouldn't run a tire with high mileage at high speed?

And what you said about the certification criteria also gives me cause to wonder: since a certification is for extended operation at speed (you indicate 6 hrs, I don't know for certain but I'll accept that) doesn't it stand to reason that a T-rated tire can run at speeds greater than 118 mph for shorter duration (do you believe a T-rated tire magically blows up at 119mph?) I ask: does anybody actually believe they can operate at even 118 mph in the USA, on public roads, for 6 hrs?? Only in the movies! Where does the 6 hr number come from? maybe the approximate length of time to cover a West German autobahn at speed? Why do we apply, as gospel, a requirement so focused on German conditions? Over there, they mean something, over here they are just plain arbitrary!

Again, I'm not saying speed ratings aren't relevant as they are: but not to what everyone want them to be. They are one indicator of the quality of a tire if for no other reason than manufacturers certify to higher ratings their top-of-line performance tires, and top-of-the-line typically means a tire has a lot of other qualities that are very desireable to enthusiasts.

And, of course, if you are actually going to operate at such speeds... in the US that typically means racing. Absolutely shop speed ratings and then dump those tires "early". Don't rely on their being safe at speed for any significant length of time/miles!

But then... even PepBoys has V-rated tires on sale! What's a tire buyer to do!

Buddywh