Yes I can see it on their dipsticks after a highway run ... plus they
"Use" more oil ... until it gets down to about 3/4 on the stick.

I've had my '84 7 passenger for 16 years so I've had plenty of time to
notice this phenomenon.

I park them on a fairly level surface and my '84 7 passenger has no
problems with the lifters leaking down.  The '85 has one lifter that
does, though, about once every month or two.  I don't see it as a
problem but might replace the lifter(s) one of these days.  The '84
Westy is a recent acquisition so I can't comment about that one yet.

Mike

David Kao wrote:
> How do you know there is oil frothing? Can you see it?
> If I fill it to the mid point between max and min on the stick
> both my 83 and 84 would make lifter noise something like
> once a week even if I drove them alternately every other day.
> But when I top up to the max they both become good boys.
> That's an obvious difference over a decade now.
>
> David