revs per mile

[siberian.mist]

every different revs per mile calculator online gives me a different number... what is the stock revs per mile? i need it for 255/35/20, im getting everywhere from 740-780 revs per mile.

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[mustangtestuser]

An online calculator will often be wrong, since they don't calculate real world variables (like load on the tire, etc.). The best way is to find the revs per mile either on Tire Rack.com or the tire manufacturer's website. I think the stock Perellis are 768 revs per mile.

[157db]

215/65R16 STOCK
8.464" WIDE
27" TALL
84.835 ROUND
747 REVS / MILE

235/55ZR17 STOCK
9.251" WIDE
27.177" TALL
85.379" ROUND
742 REVS / MILE

235/50R18 STOCK
9.251" WIDE
27.251" TALL
85.641" ROUND
740 REVS / MILE

The best way is to wrap a tape measurer
around one of your stock tires and divide
63360 by the diameter is inches.
That will give you revs/mile.
I have wrapped a tape around my OEM 16s and OEM 17s.
The above miles/rev figures are correct.

[Art161]

I have seen manufacturer statistics stating revs per mile at 45 mph. Do the revs per mile differ with speed? If so, can someone explain why this would occur?

[rford426]

i couldnt find the revs per mile on my toyo proxes 4s 255/35/20 and 295/30/20

thanks

[157db]

Originally Posted by Art161

I have seen manufacturer statistics stating revs per mile at 45 mph. Do the revs per mile differ with speed? If so, can someone explain why this would occur?

Its called centripetal force.
Have you ever seen those top fuel dragsters
make the diameters of their tires enlarge during
take-off. Same principal. The tread is trying to
get away from the point of rotation over 45 MPHs.

[AK_Kayaker]

Originally Posted by rford426

i couldnt find the revs per mile on my toyo proxes 4s 255/35/20 and 295/30/20

thanks

I think THIS is the page you are looking for.

[danbevsv6rumbler]

Originally Posted by 157db

Its called centrifical force.

Actually, such a force doesn't exist. Try reading a physics manual next time.

It's the tendency for any object along a rotation path to want to stray from the path of rotation at a tangent. A force is produced from accelerating this object, in the case of a tire: it's tread, is really the force that causes the tire to want to expand upward/outward. We commonly refer to this phenomena as centripetal force.

An object along a rotational path is always under acceleration by definition. The rotational velocity rate of change determines the acceleration, therefore, at higher speeds, a tire is experiencing a larger force on the tread that is wanting to stray tangent from the tires, which is what causes the tire to expand.

Chemistry would also show that as a tire experiences friction, heat produced from the friction will cause pressures to rise. I'm pretty sure it's safe to deduce that pressures are assumed as constant under these sort of tests.

[mygt500]

So where are the revs per mile derived from....front or back tires esp in a staggered setup.....back I suppose?

[rford426]

^^^^ good ? my front was 768 and my rear was 771 so i went with 770 i think its the closest to the two is what i guessed