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FordMan
By FordMan | AA Member | 1 Post | 1 September 2011 at 8:48pm

Please explain to a non mechanical person about those petrol numbers and is there any way of knowing which is right for which cars??

jbiddle
By jbiddle | Community Member | 1657 Posts | 9 September 2011 at 1:24pm

Refer to link provided on a similiar Q&A on this subject.

http://www.aa.co.nz/motoring/ask-jack-forum/fuel-running-costs/show/1638/

If your engine has a compression ration of around 10:1 then the lower 91 grade octane should be fine.