While Scott ponders the meaning of life
https://honda-tech.com/zerothread?id=1430227
and his confusion over where to winter vacation (monaco v. thailand?), I am trying to make an informed decsion on tire choice and can't seem to get it straight in my head.

Does anyone know the tire width of the Kumho V710 205/50/15? I see it is N/A on the Tire Rack site (maybe due to shoulder design?)
http://www.tirerack.com/tires/...+V710

But Kumho lists a "section" width (not the same) of 9.0in. on an 8 inch rim. Don't ask me why they have 8 inch when the recommended rim width size is 5.5 to 7.5 inches
http://www.tirerack.com/tires/...+V710

If the Kumho 205/50/15 has about the same tread width of the Toyo RA1 225/45/15 then I might consder it strongly.
http://www.toyo.com/tires/tire_specsheet.cfm?id=1

toyos spec sheet is a little messed up too and I figure it just slid over somehow or was entered wrong. I have thought of getting a tire that is smaller in diameter to effectively "shorten" the final (which is already 4.785). Kumho says their 205/50/15 is 22.9 in. in diameter which according to Toyo's messed up spreadsheet it looks like the 225/45/15 is 22.9 as well. So my first thought was "great it is a shorter tire". My current tire the 205/50/15 is listed as 23.0 in.

But then I look at revolutions per mile and I get really confused. Tire rack says 887 revs per mile on the Kumho 205/50/15 and Toyo site has their 225/45/15 doing 908 revs per mile. To confuse me more the 205/50/15 Toyo does 917 revs per mile but is a taller tire, 23.0. Huh?

I want a wider tire. I would like to try the V710. I am running ex SM 205/50/15 RA1s and want a change if it is better performance. I would think a taller tire would do less rpms a mile (the toyo 205/50/15) than its smaller diameter brother (225/45/15) but it is just the opposite.

I don't understand how the 224/45/15 Toyo and the 205/50/15 V710 can have the same diameter but the V710 25 less revs per mile. I don't get it but I am mathematcally challenged. Is it just apples and oranges and not useful data.

I want more grip=higher cornering speeds and a "shorter" tire to shorten up my fnial drive gearing a touch.

Help. I did do a search first. A 225/45/15 V719 might solve the whole dilemma if it would fit. I don't see where they have plans to make one at least in the V710.

Sincerely,
Confused.


Modified by apexinghonda at 10:16 PM 11/10/2005

 

Now also confused. I think they got their data mixed up...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by apexinghonda &raquo;</TD></TR><TR><TD CLASS="quote">

I want more grip=higher cornering speeds and a "shorter" tire to shorten up my fnial drive gearing a touch.

Help. I did do a search first. A 225/45/15 V719 might solve the whole dilemma if it would fit. I don't see where they have plans to make one at least in the V710.

Sincerely,
Confused. </TD></TR></TABLE>

Looks like you answered your own question. You want wider and shorter. The answer is 225/45-15. However, I would strongly recommend mounting it on an 8" wide tire, unless you have good reason to do otherwise.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by superpilun &raquo;</TD></TR><TR><TD CLASS="quote">

Looks like you answered your own question. You want wider and shorter. The answer is 225/45-15. However, I would strongly recommend mounting it on an 8" wide tire, unless you have good reason to do otherwise.</TD></TR></TABLE>

I can't say that I did and that is why I am trying to get it to make sense. I have seen several people that either race SCCA or NASA say the Hoosier R3s04 in a 205/50/15 has a tread width as big as the 225/50/15 RA1 but the spec sheets don't seem to bear that out. I have also read on here from people who say they have mounted 225/50/15 RA1s and they fit and then try the Hoosier 225/50/15 and it rubs the control arms and other things. I wished it was that easy but "it ain't". Tire size and aspect ratio is a rough guide.

I would be mounting it on a 7" tire because that is what I have for track wheels.

I would like the V710 but I want a "shorter" tire and the 225/50/15 is taller than what I have now. Thanks.

 

I have a set of the Toyo RA1 225/45/15 tires mounted on 7" wheels. The last track tires I had were Hoosier 205/50/15 Spec Miata R3S04's. The Toyos are not as wide but basically the same diameter. The Hoosiers had much more grip and decent lifespan. ALL the sizes of the 710 I have compared to Hoosier are wider than the same Hoosier size. My guess is that the 205/50/15 710 is wider than the RA1 in 225/45/15. It will also have more grip based on what others have said. The diameter does work out nicely on an Integra chassis.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">I have a set of the Toyo RA1 225/45/15 tires mounted on 7" wheels. The last track tires I had were Hoosier 205/50/15 Spec Miata R3S04's. The Toyos are not as wide but basically the same diameter. The Hoosiers had much more grip and decent lifespan. ALL the sizes of the 710 I have compared to Hoosier are wider than the same Hoosier size. My guess is that the 205/50/15 710 is wider than the RA1 in 225/45/15. It will also have more grip based on what others have said. The diameter does work out nicely on an Integra chassis.</TD></TR></TABLE>

Thanks for that useful info. . Now that is tempting now to buy the 710s. The diameter looks like it would also "shorten" my final drive but the revs per mile thing just throws me off.

 

I don't have 15" wheels, but I would assume that this applies to the 15" sizes.

I had 225/45/16 Falken GR-Beta on my 16x7 wheels. When I was at the tire store getting ready to mount the new 225/50/16 Kumho V710 on the same wheels, the guy there stacked my wheels with the Falkens next to the "not yet mounted" V710. Those V710s were at least 3" taller (meaning wider) than the Falkens.

Recently, I bought another set of 16x7 wheels and these wheels have the old BFG g-Force R1 225/50/16 tires on. I stacked them up side by side with my V710s (mounted on my original set of 16x7 wheels), the V710s were more than 1" taller than those R1s.

I've also compared my V710 with another H-T member. He has 235/40/17 Toyo RA1 on 17x8 wheel. My V710 is as wide as his RA1. This just confirms that the V710s are WIDE. Really wide.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Does anyone know the tire width of the Kumho V710 205/50/15?</TD></TR></TABLE>

I don't know exactly, but I do know with the same rim on my car, I need spacers on the rear to keep V710s from rubbing the shock. Don't need them with RA1s. On the front, the V710s rubbed in places I've never had issues with before. They are a really wide 205mm....

This has nothing to do with the topic at hand, but I am a little miffed at the last set of RA1s I got. I got a fresh set at VIR from Woodman (thanks again guys!) and only put 3 sessions on them due to rain/mechanicals that weekend. After Rockingham (total of ~110 miles over 2 days), they are all but done. I might get 1 more day out of them.

I got 4 weekends out of V710s. 1.5-2 for Toyos. Have they changed their compound???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">
I got 4 weekends out of V710s. 1.5-2 for Toyos. Have they changed their compound???</TD></TR></TABLE>

That's the rumor. You're not the only one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">
I got 4 weekends out of V710s. 1.5-2 for Toyos. Have they changed their compound???</TD></TR></TABLE>
I'm on my first set of RA-1's (only shaved to 6/32nds) right now but, FWIW, I've gotten about 3 hours of use out of them and still have measureable tread depth in all of the circumferential grooves... this was at Roebling Road with myself and the infamous Catch 22 co-driving my car.

Christian, who thinks the tires are holding up pretty damn well despite all the abuse thrown at them.

 

Seems to me that you are splitting hairs over the tire diameter issue. A difference of .1-.2 will not be perceivable. I only trust published tire diameters to about 1/4". Why? The actual distance from the axle CL to the ground will be dependent on the stiffness of the carcass, the load on the tire, and air pressure in the tire. For the purposes of this thread I would consider the 205/50/15 and 224/45/15 tires to have equal ODs.

As far as the width thing goes unfortunatly the only thing you can do to confirm which is wider is stick both tires next to each other. The "rules" on tire width are apparently open to some creative interpretation and tire mfgs are getting good at "cheating" those rules.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by paulyg &raquo;</TD></TR><TR><TD CLASS="quote">Seems to me that you are splitting hairs over the tire diameter issue. A difference of .1-.2 will not be perceivable. I only trust published tire diameters to about 1/4". Why? The actual distance from the axle CL to the ground will be dependent on the stiffness of the carcass, the load on the tire, and air pressure in the tire. For the purposes of this thread I would consider the 205/50/15 and 224/45/15 tires to have equal ODs.

As far as the width thing goes unfortunatly the only thing you can do to confirm which is wider is stick both tires next to each other. The "rules" on tire width are apparently open to some creative interpretation and tire mfgs are getting good at "cheating" those rules. </TD></TR></TABLE>

Then can you explain the vast difference in revs per mile for those three tires if the diameter difference is not perceivable? Or is the data just simply unreliable. To me it does not make sense using the Toyo data between their two tires that the imperceivable diameter difference between the 205/50 and the 225/45 have 917 vs. 908 revs per mile respectively. I would think the the "shorter" tire (although only by a little) would have more revs per mile

As to tread width and why it is N/A on the Kumhos I can only assume it is because of its shoulder design based on what you read when you click on the tire width link on their specifications page which takes you to this info below:
...
Tread Width
The tread width is the distance between the outer edge and the inner edge of the tread of a new tire. However today's radial tires often feature tread designs that incorporate rounded shoulders and there is no industry standard pertaining to "how much" of the rounded shoulders should be included in the tread width measurement. Because of this, it is difficult to accurately compare the tread width differences of one tire brand to another. Tread width measurements are best used when comparing the various tire sizes or lines manufactured by a single tire manufacturer. Several tire manufacturers have chosen not to publish tread width dimensions.

Barry H.


Modified by apexinghonda at 4:30 PM 11/11/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by apexinghonda &raquo;</TD></TR><TR><TD CLASS="quote">Then can you explain the vast difference in revs per mile for those three tires if the diameter difference is not perceivable? Or is the data just simply unreliable. To me it does not make sense using the Toyo data between their two tires that the imperceivable diameter difference between the 205/50 and the 225/45 have 917 vs. 908 revs per mile respectively. I would think the the "shorter" tire (although only by a little) would have more revs per mile

Barry H. </TD></TR></TABLE>

Tread depth?

 

The revs/mile numbers seem off more than they should with the slight difference in diameter. What may be contributing to this is the section height stiffness as mentioned above. If one tire has a softer sidewall, it will deform once weight is on it and lower the effective OD.

IMHO, I sacrifice some width to get a shorter OD on my ITC CRX due to the gearing advantage this gives me.

 

I would basically ignore the revs per mile as I suspect the numbers are junk. The effective diameters are so close on all three tires that it does not matter. I have seen some claims of more sizes next year on the 710's and the 225/45/15 was one that was mentioned. We'll see on that. Of tires you can buy today, I would pick either the 205/50/15 710 or the SM version of the Hoosier. I have the 225/45 Toyo's and they are noticeably slower than the Hoosiers were, and narrower, and do not look like the lifespan will be much longer. I'm guessing 1-2 track days more at best. I have heard numberous people this year saying that the RA-1's are not lasting nearly as long as they used to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">I would basically ignore the revs per mile as I suspect the numbers are junk.</TD></TR></TABLE>

I don't know that I would say that they are junk, but there are reasons for differences. Some manufacturers calculate outer diameter and revs per mile based simply by using the diameter calculated from the tire size, without measuring the actual tire and without taking into account any deflection at all. Some measure the actual tire, others don't; some take deflection into account, and others don't. And of those who DO take deflection into account, there are differences in the amount of deflection attributable to vehicle weight, tire inflation, etc, as paulyg rightly points out. Plus, some differences may result simply from rounding error.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">The effective diameters are so close on all three tires that it does not matter.</TD></TR></TABLE>

Agreed. For example, the diameters of the 205/50-15 and the 225/45-15 sizes, calculated from the size without taking inflection into account, are only 0.1 inch (0.4 percent) apart, so any differences in effective gearing are virtually insignificant. If you're looking for more grip, I would suggest considering a grippier tire (e.g. Hoosiers).

FWIW, I've been impressed with the tread life of the RA-1. They are lasting as long as the Yokohama A032R (usually around 1100-1500 actual track miles, plus another ~400 street miles between the track and the hotel). Tread life is roughly the same on both cars; tires have heat cycling but are not shaved. I haven't used the V710 so I can't compare that tire.

 

Just wanted to bring this thread back to find out if the original poster picked up the v710s?

I am trying to figure out myself if the 205/50/15 710s or 225/45/15 toyos will fit on my 93 civic coupe without having to roll any fenders. The wheels I am considering are enkei rpf1 15x7 41et, the car has koni yellow/GC setup with 550lb rear springs, 450lb front springs and weighs 2400lbs with driver.

After searching all the posts regarding offsets/tires etc, I cant seem to find a definitive answer. My 205/50/15 azenis on 15x6.5" rim have no issues whatsover but I thought a 15x7 would be more appropriate....

What do you guys think?

 

The 15x7 will be much better. I am pretty sure that you will need to roll the fender lips out to have no rubbing.
Why do you want to go to "R" compounds may I ask?