Not All Michelin Cup 2 Tires are Created Equal - Behind the Scenes of Making Bespoke

[Billj747]

Hey guys,

Check out my article where I dive deep in to tire technology and the effort Michelin puts into making bespoke OEM tires for a specific car model. This is written from my experience as a development driver working on creating bespoke tires for cars like the GT350/R, GT500/CFTP, and Ford GT. These concepts apply across Michelin's product line and the same amount of effort goes into creating tires for performance cars as they do for sedans, trucks, SUVs, transit vans, etc...


The article explains why replacing an OEM tire with a wider tire of the same model (even with thicker tread) will likely hurt performance, feel, be slower on track, and (if driven at the limit), will often NOT last longer. There is far more that goes into making your factory tires than you might ever have expected.


Not All Michelin Cup 2 Tires Are Created The Same - For good reason.

They may look the same, smell the same, and be the exact same size; but not all Cup 2 tires are created equal, and for good reason. Michelin produces off-the-shelf tires as well as custom bespoke tires that are engineered with specific construction, tread design, and compounding for a given car. Choosing the wrong Cup 2 tire can greatly impact the handling, feel, fitment, and performance of your car in terms of seconds per lap! Because of this, unknowingly swapping to a wider Cup 2 that has a less aggressive compound can actually make your car slower than using a smaller, stickier Cup 2 that was engineered specifically for your car, so pay attention!




https://motoiq.com/not-all-michelin-...ated-the-same/


In the article

-Michelin's development of bespoke tires for race cars and OEM street cars
-What goes into tire TREAD DESIGN: Tread Depth, Circumferential Grooves, Outer Shoulder Features & Sipes
-What goes into tire COMPOUNDING: Compound Variation Across Tread & Tread Depth
-What goes into a tire's CONSTRUCTION: Carcass Profile/Shape, Width, Ribs, Sidewall Stiffness,
-Cup 2R
-Cup 2 Connect
-How Tread Design, Compounding, and Construction Come Together
And much more...



Enjoy!

[SYT_Shadow]

Thank you for the article! Super interesting!

[SYT_Shadow]

Billj747

I have a practical application question for you.

I use 10.5" square wheels on my M3. I like running the BFG R1 tire.

Following your advice and taking the TireRack 'tread width' information, I am not sure I have done the right thing.

There are multiple 18" sizes for the BFG but we can center ourselves in just 3:
265/35 - treadwidth 10.6
275/35 - treadwidth 10.8
285/30 - treadwidth 11.3
https://www.tirerack.com/tires/tires...l=g-Force+R1+S

Also note that the 265 and 275 are mounted on a 9.5" wheel and, as you mention, every 0.5" you increase in wheel width results in a 0.2" increase in tire width.

Based on your recommendation that the tread width should be equal or smaller than the wheel width, it sounds like even the 265/35 is too wide for a 10.5 wheel


Please advise!

[CanAutM3]

Originally Posted by SYT_Shadow

Billj747

I have a practical application question for you.

I use 10.5" square wheels on my M3. I like running the BFG R1 tire.

Following your advice and taking the TireRack 'tread width' information, I am not sure I have done the right thing.

There are multiple 18" sizes for the BFG but we can center ourselves in just 3:
265/35 - treadwidth 10.6
275/35 - treadwidth 10.8
285/30 - treadwidth 11.3
https://www.tirerack.com/tires/tires...l=g-Force+R1+S

Also note that the 265 and 275 are mounted on a 9.5" wheel and, as you mention, every 0.5" you increase in wheel width results in a 0.2" increase in tire width.

Based on your recommendation that the tread width should be equal or smaller than the wheel width, it sounds like even the 265/35 is too wide for a 10.5 wheel


Please advise!

As a tidbit, it is important not to confuse nominal width, section width and tread width with the effect of wheel width. My understanding:

• Nominal width is the number specified on the sidewall and is the theoretical section width of the tire when installed on a wheel of "nominal width".
• Section width is the total width of the tire and it varies significantly with wheel width. This is the measure that varies 0.2"~0.3" for every 0.5" of wheel width variation.
• Tread width is what really matters (as stated in the article). Tread width is mostly dependent on the tire construction and varies very little with wheel width.

I believe the ideal relationship between wheel width and tread width varies depending on each tire's intended design application. There are some tires designed to have a tread wider than the wheel, so it is perfectly fine to use these in that intended context. For example, the 315/30R18 Toyo R888R has a 12.1" tread width for a Toyo recommended 11" wide wheel .