Ahh but what is he doing with them

short term, with very little difference bewteen tyres, I reckon none. Long term, and/or large differences between tyres, I reckon a reasonable amount. I dont personally think it could lead to catastrophic failure if used for normal street use.

Andrew

 

Would the diff actually be slipping though? Most of the time, the diff will only power one wheel anyway ... considering from what I remember from 1st year uni ... that power is only applied to the outer wheel in the event that the inside wheel slips.

 

Ah, but it's a limited slip diff, so it will only allow ...well...a limited amount of slip...before it locks. I guess if that slippage tolerance is continually exceeded, even in the straight ahead, it could lead to premature failure -- that's what I meant about first principles

 

as long as the "driving" wheels are the same brand/size/compound/age.... (for FWD and RWD)

 

Of course ... but if you're continually exceeding the slippage tolerance you'll be causing premature failure anyway!

I doubt either'll be a problem though, modern metallurgy is much different to that of the the day when they used to make old Datsun 180B's.

 

And if they are not..? Actually, I think the key factor is circumference, although grip would also have an effect
I'm not sure it's an issue of metallurgy, more one of unbalanced force that could dislocate bearings or other components. Diffs tend to fail..."spectacularly"

Anyway, this is all theory at the moment, apart from the experience of the guy on Ausrotary. I have searched here but didn't find anything...but then maybe I didn't look hard enough

 

Actually I think its rolling circumfrence (or was that rolling radius)...as the width of the tyre comes into it as well.

Search knows all

 

Everything is theory until it happens to me!