You need to change them when they wear to the edge of the dot.
What happens is that if you continue to run them the spring tension increases
and causes the shoe to slip more as the shoe wears down.
That in turn will cause the motor to work harder and cause the motor temps to
go up.

Got it thanks.

How are some of you guys getting up to 4 gal on the shoes? I was running the 1.0 springs with mediums on a truggy and only managed about 1-1.5 gal.

I run the hard shoes and 2x.95 and 2x1.0 springs and have had real good longevity, and that's in a truggy with a clocked 28-7. About 2 gallons on it and still tons of life left on them

Did you use your current clutch bell with any other clutch system? If so, get a new clutch bell to only use with m2c clutches. That or your clutch bell might be a little worn out.

It could also be your driving style and track conditions.
A really hard surface will cause shoes to wear quicker as you have more slip.
A weaker setup on the clutch such as .95 and .90 will also give longer life,
but that depends on you motor and driving style.

I love this clutch ever since CRE recommended it. I love the med hard shoes they last pretty long almost 2 gals with 1.0's. This clutch feels awesome with all my CRE engines.

I did use a new clutch bell but reused the springs. But this time I'm trying out the hard shoes also with a new clutchbell with 1.0 springs on a Nova plus 4 and so far it's working out great I guess I'll see if it's my driving style that wears it out.

If I run the 1.05 that give me more snap and more wear right?

Do any of you guys know the main difference between the normal 4 shoe flywheel and the steel?

Weight, the steel is much heavier. The steel slows the spool up which in return gives you less wheel spins which of course gives you more traction and run time. I got over a minute more run time simply switching from the aluminum to steel. Also I personally feel like it gives more bottom end, more usuable bottom. The only time I run aluminum is on a very high bite traction which I may only use 3-5 times a year. I run just about every week. Hope this answers your question

Thank you very much for your help. I'll be buying the steel one then.