ms3 stock tire size..little options

[rjs_speed3]

Right. The tech that mounts tires on rims narrower than manufacturer spec "wins" this argument because he's been doing something sort of dumb for the last 4 years.

Good one.

if im doing something "sort of dumb", then why don't you do my job for me then....

you should tell the other couple hundred thousand people that like to run their cars aggressively, or race, or maybe like their car to handle a little better, about how "sort of dumb" it really is to run 225 instead of 215 on a 7" wide wheel..

just a tiny bit wider really doesnt hurt... does it?

or maybe you should tell everyone to buy a whole new set of 4 wheels and tires just to run 225 instead 215..

 

[happy and angry]

if im doing something "sort of dumb", then why don't you do my job for me then....

you should tell the other couple hundred thousand people that like to run their cars aggressively, or race, or maybe like their car to handle a little better, about how "sort of dumb" it really is to run 225 instead of 215 on a 7" wide wheel..

just a tiny bit wider really doesnt hurt... does it?

or maybe you should tell everyone to buy a whole new set of 4 wheels and tires just to run 225 instead 215..

I don't think you understand what is being said here. Perhaps in your outrage you are failing to notice the two main points I am making:

- tire manufacturers list 225/40R18 as requiring a rim of at least 7.5 inches in width
- however, tire manufacturers list 225/45R18 as being just fine on a 7 inch wide rim.

Perhaps if you had spent more time learning to read instead of learning to mount tires you'd have noticed this? Maybe then you'd have realized that I am just suggesting that people run 225's that meet our rim specs? Do you think that maybe then you'd have realized I have been saying "According the tire manufacturer specs, 225/40R18's don't fit our rims, but 225/45R18's do, so I'd lean towards that size if you're going to go wider"?

 

[whitey4311]

Not to take sides but Happy is right, lol. You cant argue what is clearly listed on tirerack.com and it is exactly as Happy describes it. I didnt know this and looked into it and sure enough he is correct. I dont know a whole lot about tires and rim widths but an idiot can see the point Happy has made.

On the other hand I am sticking with OEM sizes since I found a really good tire that is OEM size and also a good choice. I am getting the Toyo Proxes T1R next week or so. I dont consider a savings of $80 over the ECSTA tires to be a wise alternative when comparing a Toyo to a Khumo so I will fork over the extra cash. Also to spend $20-$40 more then per tire above the Toyo' I dont think is the best balance or price vs quality. Time will tell how good these are going to be but all the reports and reviews love them even on the high end cars.

I thought I had a bit more life on my Potenzas but I am at 22k+ miles and got down on my knees to look at the inside of the tire and it was bald as s***. I guess the camber these cars use allows the inside of the tire to wear most. Although, I think it is a appropriate amount of camber since most of the tire is evenly worn and to the wear bars. The sacrifice for performance seems to be right on the money because its not like the inside wore bald while the rest of the tire was still good.

 

[ericrapp]

I don't think you understand what is being said here. Perhaps in your outrage you are failing to notice the two main points I am making:

- tire manufacturers list 225/40R18 as requiring a rim of at least 7.5 inches in width
- however, tire manufacturers list 225/45R18 as being just fine on a 7 inch wide rim.

Perhaps if you had spent more time learning to read instead of learning to mount tires you'd have noticed this? Maybe then you'd have realized that I am just suggesting that people run 225's that meet our rim specs? Do you think that maybe then you'd have realized I have been saying "According the tire manufacturer specs, 225/40R18's don't fit our rims, but 225/45R18's do, so I'd lean towards that size if you're going to go wider"?

So with the formulae in place, can the 215/40 work? And as I mentioned before I could run 195/ and with a softer compound have more traction than stock. It seems tires are designed differently also. Is the width measured at the theoretical contact patch{tread surface ] or does it include the radius from tread to rim? I ask because some tires seem to to have a bowed sidewall and others not so much. But the sizing is the same when purchasing? i bet both you guys can help on this one

 

[whitey4311]

Getting the Proxes T1R this week at $771 out the door. ****!

I priced out buying online and taking them in to WalMart for mount/balance and would save only $70. Since buying them from the shop gets me free balance and rotations the savings would get eaten up in no time and isnt worth it.

Doing this every year is going to get old real fast, lol.

 

[sperry]

I don't think you understand what is being said here. Perhaps in your outrage you are failing to notice the two main points I am making:

- tire manufacturers list 225/40R18 as requiring a rim of at least 7.5 inches in width
- however, tire manufacturers list 225/45R18 as being just fine on a 7 inch wide rim.

Perhaps if you had spent more time learning to read instead of learning to mount tires you'd have noticed this? Maybe then you'd have realized that I am just suggesting that people run 225's that meet our rim specs? Do you think that maybe then you'd have realized I have been saying "According the tire manufacturer specs, 225/40R18's don't fit our rims, but 225/45R18's do, so I'd lean towards that size if you're going to go wider"?

So what do you have to say about the RX8 autocrossers that run 285/30's on 18x8's?

...I mean, other than "autocrossers are insane to pay for the 15 hours of shop labor it takes to jam tires that big on stock rims". :lol:

 

[happy and angry]

So with the formulae in place, can the 215/40 work? And as I mentioned before I could run 195/ and with a softer compound have more traction than stock. It seems tires are designed differently also. Is the width measured at the theoretical contact patch{tread surface ] or does it include the radius from tread to rim? I ask because some tires seem to to have a bowed sidewall and others not so much. But the sizing is the same when purchasing? i bet both you guys can help on this one

Just check Tire Rack. Search for tires of that size and click "specs", then look at the rim width range. Read the FAQ on the rim width range, too, just so you know what's going on. A link to show you the page I'm talking about:

http://www.tirerack.com/tires/Spec....&vehicleSearch=false&fromCompare1=yes&place=0

Our rim is 7" wide, but you can squeeze a tire that requires an extra half inch (or inch if you're nuts), but you'll have to be careful with it and how you run it. Maintain pressure properly, maybe even a touch high to add extra support to a stretched out sidewall, and you can probably run it fine. If your tire fails running on a rim too narrow for its rim width range, though, you'll have no recourse with the tire manufacturers.

The other thing you want to do is make sure whatever tire you buy will stay within a few percentage points (~2 is probably good) of the total stock wheel/tire combination's diameter. You can check out tire diameters here:

http://www.miata.net/garage/tirecalc.html

When you compare 215/40R18 to stock 215/45R18, you're running a bit smaller than stock. This will affect the speedometer and may affect electronic nannies like traction control and ABS sensors that depend on an accurate speedometer to do their work.

Why not just run a 225/45R18? The sidewall is not going to look that much bigger than stock, you'll get a wider contact patch, it fits on the rim, and the tire/rim combination is within 2% of stock diameter.

 

[sperry]

The other thing you want to do is make sure whatever tire you buy will stay within a few percentage points (~2 is probably good) of the total stock wheel/tire combination's diameter. You can check out tire diameters here:

http://www.miata.net/garage/tirecalc.html

The best way to compare overall diameters is to check the revs-per-mile for the exact tire you're thinking of buying on the tirerack specs page. The tire calc uses estimates, and the actual overall diameter varies from tire to tire even when they're the same size according to the sidewall markings.

 

[happy and angry]

So what do you have to say about the RX8 autocrossers that run 285/30's on 18x8's?

...I mean, other than "autocrossers are insane to pay for the 15 hours of shop labor it takes to jam tires that big on stock rims". :lol:

They don't run them all day on the street, do they? (If they do, I think they are insane ) Tire failure on a track in a controlled environment is much less bad than say, in traffic.

Racing applications are not quite the same as street. On a track you're always careful with pressures, constantly checking your tires for sidewall deformations and tread life, adjusting for weather, etc etc etc. Tires on the road need to run thousands of miles in varying temperatures and weather conditions, different road conditions, and generally without a lot of oversight. Most people don't pay the same amount of attention to their daily driver tire pressures or states of wear that people that track their car.

 

[happy and angry]

The best way to compare overall diameters is to check the revs-per-mile for the exact tire you're thinking of buying on the tirerack specs page. The tire calc uses estimates, and the actual overall diameter varies from tire to tire even when they're the same size according to the sidewall markings.

True, but it's not off by that much. But it's a good way to ballpark it. Tire diameter can vary if you run a few PSI off normal, for that matter.

 

[Engineer420]

I just bought a set of the new bridgestone potenza RE760 sports..225 /40/18. I saved about 400 dollars instead of buying the stock 215/45/18 and I got a better tire. Much nicer tread.

The Fit is better than i thought..I was concerned about the bulge but it looks fine and the car is about an 1/8 of an inch lower.

 

[sperry]

They don't run them all day on the street, do they? (If they do, I think they are insane ) Tire failure on a track in a controlled environment is much less bad than say, in traffic.

Racing applications are not quite the same as street. On a track you're always careful with pressures, constantly checking your tires for sidewall deformations and tread life, adjusting for weather, etc etc etc. Tires on the road need to run thousands of miles in varying temperatures and weather conditions, different road conditions, and generally without a lot of oversight. Most people don't pay the same amount of attention to their daily driver tire pressures or states of wear that people that track their car.

I was just poking the thread with a stick.

For reference, I run 255/40's on an 8" wide wheel on the racecar, but 255/40's on a 9" wide wheel on the street. Plus, the street tires are actually about 1.5" narrower than the race tires, even though they're both 255's.

My point is: the size on the sidewall isn't exactly gospel. Look up the specifics for the tire and see what the manufacturer requires. Depart from their recommendations at your own risk.

 

[happy and angry]

Look up the specifics for the tire and see what the manufacturer requires. Depart from their recommendations at your own risk.

+1 a billion times.

 

[pointysticks]

i have put a hurtin, on two sets of kumhos mx's. track time, AX, and happy go lucky street time. those things are bomb proof, and are very predictable on a track. i now run toyo RA1's on the track, but for the street, i will check out kumhos, for all my cars. they dont suck.

i will stay with the stock size on the MS3. the extra grip you guys feel on the streets is negligible, and probably more of a placebo. now if you want to LOOK good, no arguing that.

 

[ericrapp]

I was just poking the thread with a stick.

For reference, I run 255/40's on an 8" wide wheel on the racecar, but 255/40's on a 9" wide wheel on the street. Plus, the street tires are actually about 1.5" narrower than the race tires, even though they're both 255's.

My point is: the size on the sidewall isn't exactly gospel. Look up the specifics for the tire and see what the manufacturer requires. Depart from their recommendations at your own risk.

Thanks that is kinda what I figured. There certainly is some engineering involved with matching tire to a wheel to a car with a specific suspension set up. Thanks

 

[lenmakya]

There are several online stores that sell tires. But my sister and her husband were very pleased with: www.clicktire.com as they cater to specific needs and budgets at their online store. They also offer the provision of writing to them so that they can find the size of the tire according to customers specifications.