how do you figure out what tire sizes are needed to keep all settings normal when upgrading from a 245/50/16 to a 17 or 18" size rim?

say using a 265 or 275 front and a 295 rear..

 

275 x .45 x 2 divide by 25.4 + 17 = 26.7 inch wheel


215 x .65 x 2 / 25.4 = 15 = 26.0 inch wheel

 

there is a rule of thumb called +1 you go up 10 on width, down 10
on aspect ratio and up 1 on rim size. this will be very close.

245/50-16
255/40-17
265/30-18
275/20-19

but won't always be exact here are the tire sizes that are exactly the same height.

245-50-16 is 25.7" tall
275/40-17 is 25.7" tall
315/35-17 is 25.7" tall
275/35-18 is 25.7" tall

http://www.smokemup.com/auto_math/tire_diameter.php

 

thanks for the info..


according to that chart it seems i would have to go a 275/35 in the front and a 295/35 in the rear to get a close height in 18

 

Using the formula in my prvious post I get 25.5 inches and 26.1 inches for the 275/35 and 295/35 respectively on an 18 inch rim.

 

thanks...

 

Hey,

How can you find out what tire to get if you want a low profile tire?

How can you tell how wide the tire is?

thanks

 

run flats??

first of all these tires only come in certain sizes which are extremly limited and they ride terrible when compared to similar tire sizes from other companies.

why do you want those; is it truly for the use or to have the name?




to answer your question on profiles you understand how to read a tire correct? in otherwords a 245/50/16 is taller than a 245/45/16 but at the same time a 275/45/16 is going to be taller than the 245/45/16.

the first number depicts how wide the tire is....most 17 size rims have anything from a 245 to a 275 as the norm. most 18 rim sizes if they are 9.5 or larger again use the same diameter. it's only when you step up to a 10.5 or larger that you'll see the need for a larger tire than a 275.


tire size first of all depends on the width of the rim and secondly on the size of the rim wether its 15 or larger like a 18. once you have the diameter down you then choose the width keeping in mind that a 9.5 is about the widest rim you'll fit with little to no modifications in the front wheel wells. then you pick your tire height according to the area your driving in as well as the width of the tire you've chosen.

two tires with the same profile of a 40 series; the one that's wider will be taller....so you have to take all things into account. main reason why you see me posting everywhich way trying to get enough info before i pick my tires. i thought rims were the hardest things to choose.....i was wrong.

 

thanks for all the info.

By run flat I do not mean true run flats, sorry just used to calling tires that look like run flats, run flats. I mean the tires with extremly low profile. I am thinking of running something around 10 inches wide on a 17 or 18 inch rim on the rear and 17 in by 8 or 9 inch wide.

Thanks for your help:hail: :hail: :hail:

 

little confused by that post but as far as i've seen 9.5 is the largest in a 17...although i'm sure there are others out there.

the most common of this size is the TTII's.

if you want to step up to the 10" or more prominent 10.5 wide rims to run the larger tire sizes they your going 18's.

good luck with it, i know i'm having a hell of a time. :lala:

 

I found some afermarket z06 take offs with 17s at 10.5

 

But I will probabl be using 18 in the rear anyways

 

Ya, dont ever get runflats, I got a set of goodyear GS-C's 285/40/17 for the rear of my camaro, they are the worst tires I have ever had!!!

 

what did you not like about them?

 

Too much road noise, and all round crappy tires, that could just be because they were GS-C's though. They had no traction at all!!! I had donlop sp5000 on my stock 16" rims, the tires stuck like glue, Threw on the goodyears and a new set of rims, good bye traction, hello wheel hop!!! had to get some edelbrock lower control arms to solve that problem.

 

wow, just seemed like they would handle more power and higher speeds.

Thanks for the info

 

where did you find the 17x10.5?

 

I found them in corvette magazine. Performance wheel outlet. They have 17x11 too and 18x10.5.

www.performancewheeloutlet.com

 

Somebody maybe already said this in different terms, but say for instance with a 245/50/16 tire:
245 = Tread width in millimeters
50 = Sidewall height is 50% of tread width.

To find total tire height, multiply sidewall height by two and add rim diameter.

 

Are there profile tires for 18 inch rims?

Does the vette have run flats or profile?

thanks:hail: :hail: :hail:

 

show me the exact place on the site where you see this....i only see 17's in 9.5 as the widest unlike the 18's.


what exactly are you asking....?

are there profile tires for 18" rims? yes

what profile do you want?

corvette uses a 40, i have 35, some have 30....trucks go as high as normal cars which can be around 50+ if needed.

do vettes have runflats or profile?

what are you asking here? all tires have a profile.....runflat is a type of tire made by a certain brand. corvettes typically come stock with them.....are they prefered? no.


hope this helps...

 

I thought runflats were a type of tire?
I am confosed now

 

i don't know what your asking if they are run flat or PROFILE tires. but the c5 vettes have 245/45-17 run flat front and 275/40-18 rear run flat. the zo6 has 265/40-17 front and 295/35-18 rear.run flat tires have stiff sidewalls. so stiff, they will not flex. which is why you can run them w/o air in them.

the zr1 corvettes had the 17 x 11 rims on the rear.

 

oops,

I see why I am confusing you guys, I thought run flats were a type of low profile tire.

Are there many low profile non-run flat tires for 17 inch plus rims?

Thanks:hail: :hail: :hail:

 

yes

 

Alot of confusion on this thread.

The first number of the P-metric size coding (P245/50R16) is the section width of the tire, not the tread width as stated above. In other words, a P245/50R16 (or even a 245/50R16) tire is 245mm in section width. Depending on the design of the tire, the actual tread width could be from 85% to 95% of the section width. The section width is defined as the overall width of the tire section, this would be a measurement taken across the mid-sidewall location on each side of the tire.
I should know, I have designed tires for 28 years, take my word for it.

"Run flat" tires: Run flat tires are designed so that in case of a puncture and the tire looses all of its inflation, the tire can still be driven about 50 miles at reduced speed, enpough to get you off the expressway anf into a service station. They are usually very hard for ride.

 

Do tires have a grip rating to how much they will hold a corner or anything?

thanks:hail: :hail: :hail:

 

There are the three UTQG ratings for wet traction, temperature, and treadwear. These ratings must be stamped on the sidewall of every passenger tire sold in the USA.

Nothing for grip or cornering or handling.

The wet traction and treadwear tests and subsequent ratings are done versus a control tire.

 

understand as well the smaller the sidewall the more chance for "lift" when taking hard turns..........so don't think you can pull a 90 mph exit ramp move with really low profile tires.

you have to counter balance everything and keep proportions equal.

 

thank for your help, learning alot now