Why did someone have to mention oil, the word oil should be banned on the forum !
I'm 62 now and have been working on engines either as a full time mechanic or "after hours" since I was about ten, I must have pulled down hundreds of engines in that time. In all those years I have never seen or even heard of an engine fail/blow up/wear out prematurely where the cause can be directly attributed to the oil. I lived and worked in central Australia for many years and have seen a couple of engines that were driven for a couple hundred miles on totally wrong oil (oil from a windmill in one case) just to get the people home.
Now there is no doubt in this case Penrite are going to push their own product, they wouldnt be very good at their jobs if they didnt. However I do use their oils in all my bikes, moderns to old ones.
I own a 1000cc Moto Guzzi that I bought new in 1994, it currently has 111,000 k's on it. I have run it on Penrite HPR 30 from new with changes every 3,000 k's which by modern standards is a short oil change period. Now Guzzi's are renown for lasting a long time but my bike after 111,000 k's doesnt use any oil at all, the oil comes out after 3,000 k's nearly as clean as it is when its put in and I have never had to adjust the tappets. All of which means there must be little to no wear in the engine including cam and tappets, no valve recession. Wether this is due to the oil or the quality of the engine is of course debateable.
So my take on the subject is if you use any brand of oil that is a half decent product you will be ok. All the talk about you must run one brand or a straight grade etc etc is a load of bollocks in my opinion.
So there ..........................................