No, but if you start using synthetic you have to stick to it or it will fuck your engine up when you got back to the dirty stuff.
I think we discussed this here before, something about the sythetic cleaning away residual goop from the old stuff and revealing cracks/worn seals/etc that had otherwise remained plugged by the goop.
Coarse edged youth, the irish pendants string from their smiles
not yet plucked as to slacken the seams
and drag down the features of age,
no folds or creases from unkempt wear
eyes of tranquilty, crystalline-beads
no sign of despair in their hair, nor their hearts
but oh they have yet to be experienced and that makes aging so very worth it...ML circa2012
You nailed it Manic ... plus the synth loosens up chunks of sludge that then get to wander around the engine on there way to the oil filter.
If you have already done the deed run a bottle of Lucas moter flush before you change your oil.