[beach57]

If breaking in a cam you should use an oil for that then dump then use oil for engine ,see what the cam make recommends ,as on fast and load did not which they found to there cost,they put an additive in which did not work and destroyed the engine.

 

[beach57]

If you use straight 30w oil you should not then use a mutigrade as 30w oil sticks the bits carbon etc it to the insides of engine and multi grade keeps it in the oil ,so when switching the multi cleans the insides so you get a sudden dump of crap going through the bearings etc, thus knocking engine.Also you should not put oil in a hot engine as it destroys the additives,warm yes, hot no.This was from BP yrs ago.

 

[beach57]

Are not new production engines run in before entering the car,or components made of alloys so as not to,remember the old days or signs in the back of cars running in please pass.On cam breaking in oil use what the cam manufacturer recommends,on mutli grades this is why you should oil change every 3k and oil filter every 6k,also did anybody see 5th gear about oil,they did a test on a golf with its old oil in ran a 1/4 ,then oil changed for new and gained 1/2 sec on the 1/4 mile.