10W40 is typically a semi-synthetic that's good for oil change interval of 10000-12000 km , IMO .
I did 15000 to 16600 km with a Euro ACEA A3B4 spec'ed Total 10W40 .

10W30 is typically a mineral oil, an ACEA spec'ed oil would be good for 7000-10000 km easily , IME .
Unfortunately it is not available where an Euro 10W40 semi-synthetic is always available at Aeon Big/Giant/Tesco etc at a promotional price point of RM80-100 per 5 Litre pack .
Heck, you can always get fully synthetic (0W40 or 5W40,5W30) at RM100 from time to time from supermarket promotions .

This post has been edited by zeng: Feb 1 2020, 10:23 AM

0W40,5W40 ACEA A3B4/C3 are thin for a 12 yo Myvi whose manual calls for xW30/xW40 SM Ilsac GF4 ?
Wish you aren't joking ?

I'm afraid 5W30 ACEA A5B5 or A3B4/C3 is not 'thinner' than an xW30 SM Ilsac GF4 called for in the Myvi manual .

This post has been edited by zeng: Feb 1 2020, 12:38 PM

Sorry, I would like to stick to the goal post(s) as set out by OP .
I can accept OP shifting goal post(s) though .

OP, you may consider this Shell Helix HX8 5W30 (which someone here bought online cheap) for the 12 yo Myvi .

It has an HTHS (High Temperature High Stress ) @ 150*C of 3.5 cP or more .
I'm sure Shell Malaysia would consider your 'guarantee' request , if you choose HX8 X .

This post has been edited by zeng: Feb 3 2020, 11:26 AM

https://forum.lowyat.net/topic/4192241

Perodua recommends engine air filter change every 40,000 km ,as someone suggested .
During my typical oil change intervals of about 15,000 km , my mechanic normally 'blow and clean' my air filter on his own initiative (Maybe ,he understands my preference or bias) .
Having said that, when my mechanic ever suggests changing the air filter (like RM25) I would always comply as it would have been in use around 60,000 km or more knowing he is being helpful not to waste .
Having gone through some used oil analyses (UOA's) and blotter spot tests , IMO engine air filters (and oil filters) are being replaced and changed ever so often ......

This post has been edited by zeng: Feb 5 2020, 10:24 AM

Well, any branded (and Euro ACEA spec'ed) engine oil like Shell Castrol Total Elf Mobil ACEA AxBx or Cx etc from Aeonbig/Tesco/Giant is genuine IMO .

This post has been edited by zeng: Feb 5 2020, 10:29 AM