Engine oil (resend)

["PDMG" <paulg@xxxxxxxxxx>]

I have just bought an ex UK '88 325i SE. I know it's history and it 
has 87K genuine miles on the clock. It's been serviced regularly, 
(the book has the BMW Dealers stamp on every service), but I 
don't know what type of engine oil has been used. The 
complication here is that the Dealer is in England, and I now have 
the car in New Zealand. The UK spec. 325i SE was the highest 
performance 325 back then, developing a little over 171bhp. Having 
in mind our very mild climate in northern NZ where a frost is a rare 
occurence, and summer temps regularly climb into the 90'sF, 
would a 15W40 oil be OK? It's likely to be a Shell oil due to a 
business connection I have and they market (in NZ) a 15W40 
which is synthetic based. (Shell Helix Plus) It's not a full synthetic 
and they describe it as "semi-synthetic". 
Any advice welcomed.

Paul Graveling
88 325i SE
89Toyota Four Runner.
New Zealand.

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