wira ... only first batch is best. after 1998 or 2000 almost all rubbish.

Yes, Iswara first batch also the best. After that all lousy too. Why> cos Proton wants to impress the buyers first...and when word goes around that the car is very good then they cut costs by using cheaper parts from second batch onwards.

after making this discovery, i feel like i have been cheated all this while. i live in malaysia. i dont need multigrade bullsh*t that gets thinner faster. i should have been using cheaper, better monograde on all my cars all this while.

I don't even know that there is mono-grade oil out there

Anyway, since my car is service at SC because under warranty then just let it be. The SC will put the full syn because they can make more money

We are hot country, there is no need for W (winter) rating here. Monograde should do fine.

Iswara? Multigrade? LOL
Iswara can use subsidised cooking oil also. RM10 kaotim.

You are right! Many people also didnt know

up

UPDATE: after 3 months using monograde oil, my car takes 2 cranks to start in the morning. I think initially it was perfectly fine because there was still some residual EO (castrol magnatec probably was still sticking to the pistons and cylinders) but over time, the magnatec wore off. So, the monograde oil isnt fluid enough for a one time crank during early morning. But once it starts, it works fine. The engine still runs cooler than when i used multigrade oil.

if your engine is new, I wouldnt recommend using monograde oil just to make sure you have proper protection during the early morning cranks. but for old cars which might burn multigrade EO, its probably a better choice to use monograde because it doesnt suffer from thermal breakdown as quickly as multigrade so there is overall less chance of damage to the engine.

so are you happy using monograde ?

20w40 and 15w40 are actually the same viscosity during normal temperature. Both 40.
I believe your first one might be 20w50 which usually makes the car really sluggish and slow.

later just dump this 4G61 engine into your Iswara

IMO, its the best option for my iswara so I will stick to monograde for this car. multigrade oil tends to degrade quite fast in this car so it is a less reliable choice than monograde. i have googled and there doesnt seem to be any issues with cranking twice. cranking for long periods more than 10 times a day is when you start to see wear on the starter motor, flywheel and carburetor so I dont think my 2 cranks lasting 1 second each time would cause any significant issues.

Actually, multi-grade oil does still matter even in country like Malaysia. The "W" does not only indicate winter usage. A 15W-40 oil is about as thin as SAE 30 oil so it flow better than a SAE 40 oil at normal cold start temperature of around 30c but it stay as thick as SAE 40 oil at engine running temperature.

Most of the time, it won't happen in a short time but long term excessive wear on engine can happen during the first few seconds of engine cold start if the oil is too thick for a fast and smooth pump during cold start. This is especially true for a car that are not start often, for example, once every few days. Oil pump, filter and other key areas has to be taken into account as well. There are reasons when the car manual recommend a 5W-30 oil rather than a 10W-30 oil or SAE 30 oil despite all of it being a SAE 30 grade oil at normal engine running temperature.

This SAE 40 oil, like other monograde oil, are usually only used for older engine model and design or where engine condition are no longer at its optimum level or car that are up and running most of the time such as taxi for cost effectiveness reason.