Recommended oil for FD - original 13B engine

[LynneE]

Hello guys,

Apologies in advance for such a basic question, but what is the oil of choice for an absolutely unmodified, bog standard, stock 13B engine (1995, UK spec, non-import)?
The Mazda main dealers here in Cardiff always service the car (they still have a rotary specialist technician!...), but they have recently started using 5W-30 semi-synthetic, instead of the 10W-30 full mineral oil that the manual recommends.
I've been looking at some brands on-line and wondered if anyone had experience of this one:

https://www.millersoils-shop.co.uk/millers-oils-classic-pistoneeze-10w-30-engine-oil

Any advice or recommendations gratefully received.
Cheers!   
Lynne

[RE5]

Hi Lynne,
There has probably been more written about "Which Oil to use" on Forums than any other Topic.
I use either 10/15  w 40 & use a known Brand like Castrol GTX, Shell Helix ... (these are Part or Semi synthetic) in both my FB & FC TII & change once a year or every 2000 mls & change the filter every 1000 mls.   Good quality Mineral is hard to find now,  do not let them put in fully Synth as  the engine soft seals are not used to pure synthetic & have been known to expand & fail as a result.
I hope this helps,
regards Pete

[LynneE]

Thanks Pete - your reply is much appreciated.
I have a rather elderly 'can' of Castrol which is all mineral, but the newer 'Magnatec' varieties available for purchase now seem to be synthetic, so I have avoided these.
Perhaps the semi-synthetic that Mazda are using is not so bad then? I would just feel more comfortable with the viscosity the old manual recommends.
Thanks again for your time! 😊
Lynne