Is it too late to switch to synthetic? My '90 300SE has 230K on it. During its life, it has had frequent 3K-4K oil changes with alot of highway miles.

It presently leaks a little at the timing chain cover but doesn't seem to consume much oil. Am I looking for trouble if I switch to synthetic?

Thanks,

Mr. BILL

90 300SE
85 300D
84 300SD (sold)