Mazda-Menders

Not to worry, I've got 10W30 Semi Synth to go in next till it's run a few miles.

Can judge how it's running after that, plan was to put fully synth in as I've no record on oil change history. Hopefully no harm in trying, regardless, if it's the wrong stuff another oil change will be beneficial in the long run.

The block originally started its life in a 323, and was re-worked for the Mx-5/Roadster the engine was built and engineered and tested to run on semi synth oil, or also known as part synth, 10/40 or 10/30 here in the UK, forget the rest for the minute as they just have different grades of semi synth dependent on the countries temperatures and conditions, The MK 1 from 1989 to 1997 uses and states semi synth the MK 2 1.8 and 1.6 from 1998 to 2001 states semi synth, the MK 2.5 1.6cc from 2001 to 2005 states semi synth, the Mk 2.5 1.8 VVT from 2001 to 2005 states fully synth, MK 3 fully synth and the MK 4 fully synth.
Mazda did not spend millions engineering these roadsters to run on the wrong grade oils, they state the oils to be used for the reasons they built them and tested them with at the time, using the wrong oils will do more harm than good.
M-m

Mazda Mender wrote:The block originally started its life in a 323, and was re-worked for the Mx-5/Roadster the engine was built and engineered and tested to run on semi synth oil, or also known as part synth, 10/40 or 10/30 here in the UK, forget the rest for the minute as they just have different grades of semi synth dependent on the countries temperatures and conditions, The MK 1 from 1989 to 1997 uses and states semi synth the MK 2 1.8 and 1.6 from 1998 to 2001 states semi synth, the MK 2.5 1.6cc from 2001 to 2005 states semi synth, the Mk 2.5 1.8 VVT from 2001 to 2005 states fully synth, MK 3 fully synth and the MK 4 fully synth.
Mazda did not spend millions engineering these roadsters to run on the wrong grade oils, they state the oils to be used for the reasons they built them and tested them with at the time, using the wrong oils will do more harm than good.
M-m

Ok, message received M-m, looks like I'll be returning the Fully Synth oil. It's 5W30 part synth I'll be putting in, thank you.

Another useful post. I was wondering what grade to put in my Black-in before it goes back on the road in spring.
Semi-Synth 10/30 or 10/40 it is

10W30 is not impossible to get in the UK but it is basically a US oil grade as virtually no UK engine oil blender produces it.