No one blows an engine (due to lack of lubrication) while using API
certified oil that has been changed regularly and kept up to level.
i will address stan's comments.
i have studied oils since 1961, and have taught lubrication at
automotive and industrial businesses. the catch phrase is changing oil
regularly. there are so many variables in this dept.
for example - on mineral based oil, the API classification is based on
the temp. of 180 degrees in order to come up with it's standards. but
the society of automotive engineering states that for every 20 degree
rise in the base line, will cut the life of the oil by 50%. so, if one
was to put this oil in the family station wagon, pack it full of kids,
and people plus luggage, add a heavy trailer to drag down the road,
turn on the a/c, and head for the mountains on a hot summer day. what
is the life of the oil? could be over in less than 2,000 miles. now,
if someone was into abusing the engine, then many of the properties of
the oil have changed and may not offer the protection as fresh oil.
i could go into synthetic oils, but let me say this since it is coming
upon the growing season. take your old trusty lawn mower out, chank it
up and made some passes and push the mower to the choking point, but
don't let it die. notice where this point is. then, if you want.
change the oil with fresh mineral based oil and do the same thing.
after you are satisfied where that choke point is, then put in synthetic
oil in. (doesn't make any difference in brands) and go cut the same
lawn and notice where the choke point is. remember, you haven't done
anything to the mower, just change oil. and if you see any improvement
on a 3 1/2 hp engine, think what you would see if you have a 150hp
engine. then write back to the newsgroup and tell what you found out.
and tell how slow the synthetic oil gets dark. then you decide whether
or not it's worth the difference.
it's not me telling. people say put up or shut up. well, there's the
challenge and it's your mower, your lawn so how can it be fixed?
you will notice a difference, but you will be surprised of how much.
knowledge is power - growing old is mandatory - growing wise is optional