Join Date: Aug 2007
Location: Staunton, VA - USA
You don't say where you're located, but if it's in the USA any car produced by 1988 should have been equipped with seals that are compatible with ethanol in fuel if they were destined for the US market originally. I'd be shocked if there were any difference in seals used no matter what market the car was originally destined for.
I have no choice, and have not for decades, to use ethanol-free fuel routinely and my 1970s vintage SY cars have had zero difficulty with it. When it comes to octane rating, I subscribe to the philosophy that the lowest that can be used without causing knocking/pinging is just fine. Modern engines with electronic spark control will adjust as needed to prevent knock, though I cannot say whether the 1988 SZ series had knock sensors or not. I have been using US regular [87 octane via the (R+M)/2 - AKI method] in my SYs and used it in my 1999 Jaguar as well with no loss in performance or efficiency for my driving habits.
I've been using 10W40 rather than the originally recommended 20W50 in my SY cars for quite a while now. Conventional oil, as the changes are so frequent that there is very little (if any) benefit to synthetic (in my opinion - others will disagree vehemently).
The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth. ~ Niels Bohr