I've been pondering the same question. When my Herald Coupe's been
re-pistoned, bearing-ed et al, what should I use? Synthetic, mineral or the
cheapest I can find in the supermarket?
Decided to have a chat with an old chum of mine in Shell who is a marketing
chemist (whatever that is) and fairly clued up on modern lube suitability
vis a vis older engines. I respect his opinion and as he runs an XK120 and
a 150, thought I'd ask what he puts in those.
For a start, its not synthetic. Even with his employee discount, (yes, he
does claim to buy it) he says he can't afford it. However, the following
are his views, not mine........
MINERAL?
Cheaper, gets dirty, advisable to change regularly, has many technical
shortcomings for the MODERN engine. Older engines run at lower operating
temperatures and pressures which are well within the scope of the excellent
additives blended into mineral lubes.
SYNTHETIC?
Far more expensive compared to mineral. Alleged to find lots of leaks in
older engines where they didn't leak with mineral. Keeps things inside
squeaky clean and capable of taking a lot more abuse than mineral as well
as lasting longer. Question to me "Do people really want to treat their
cars that hard for the benefits of synthetic to become apparant?"
Apart from the leaks and cost angles, I commented Synthetic was probably a
better bet. His reply was that he thought it was money wasted because the
vast majority of classic engines worked no better and probably lasted no
longer with synthetic than mineral. On the cleanliness aspect he felt a
change every 3000 miles with a new filter but using a flushing oil between
every other change was a better and more practical alternative.
That's good enough for me, maybe not for some of you, so each to their own.
The Herald will continue to have a diet of Castrol GTX in the engine and
super thick industrial treacle in that abortion of a back end to hopefully
shut it up for all time. BTW, re-built the rear spring over the Easter
holiday. Now got rid of the rust, moly'd, new interlayers between the
leaves and wrapped up snug and tight in a greased Wefco spring gaiter I
salvaged from a garage clear out four years ago. I thought I'd better throw
away the Nylocs - so spent all my pocket money on some nice new ones and a
bottle of threadlock. No doubt when finally installed, car will still look
as though someone has kicked it up the backside. Wouldn't be a Herald if it
didn't.
John Mac
|