tl;dr version:
accidentally bought and used monograde petronas mach 5 SAE 40 in iswara.
what are likely adverse effects of this?

i recently serviced my old iswara (1998). I usually buy my own engine oil coz my mechanic doesnt stock the brand of oil I want.
in the past, i always use magnatec 10W40 for this iswara but my mechanic recently told me its too thin to protect my old engine so he recommended i switch to mineral oil - petronas mach 5 specifically.

so i went and bought a petronas mach 5 engine oil. since this is the first time im buying mach 5, i didnt really check properly what i bought.
turns out, i accidentally bought the monograde version, SAE 40. i only discovered it while i am preparing to buy another canister for my next service.

to be honest, i am quite happy with the oil, the car started fine and the engine runs cooler and smoother with less vibration than before which was a surprise to me. seems like a good move from magnatec to mach 5 monograde EO for an old magma engine.

but i am a bit apprehensive that my engine is not getting the protection it needs during morning starts. is this really a valid concern or is SAE 40 actually perfectly fine to use in Malaysia?

Likely fine. Dont get cold enough here to need multigrade. You want to look at the upper number anyway.

Is fine..my bike using SAE 60 monograde.. nothing happens even went to "cold" places in Malaysia.. still running fine..

thanks for the feedback, guys.

and to further confirm that its fine with technical data, i just found this chart below that shows SAE 40 grade oil actually has lower viscosity at 20 deg C than 10W40 grade oil at 10 deg C.

since the malaysian climate is between 22-32 deg C and 10w40 oil is designed to work in temps as low as -30 deg C, i can safely say that monograde SAE 40 is perfectly fine to use in malaysia.

I'll probably stick to using monograde for my iswara coz its cheaper and works great.



This post has been edited by homicidal85: May 25 2022, 10:23 AM

can use la. no issue.

My spare Car is also Iswara. Yes, old engines need thicker engine oil to protect its internals. Ideally 20w/40 la...thicker so it lubricates and sticks onto each internal part nicely to protect it from wear and tear.

You can get away using the thinner 15w/40 if your engine has been well maintained.

Iswara still road worthy?

Iswara surprises me too. My regular car is a BMW, but I find myself driving the Iswara more often than not LOL! it is the workhorse that taxi drivers in the 90's,00's and 10's love the most thx to its super tahan lasak engine and tough as iron gear box.

Most new Spare parts are so cheap...cheaper than even Kancil and Kelisa! I will never sell my Iswara

4G spare part now no original. Almost OEM that why is cheap.

even those days when the spare parts are original, the prices are still lower than Kancil's and kelisa's original spare parts. I know la..cos my good buddy has a Kancil and Kelisa in his house both used by his 2 younger sisters....and we often talked about cars those days.

I use Shell 20W-50

Buy 20W/50 for older car

where do u stay?? mount kinabalu?? or genting highland??

even if at genting highland should not be a problem. just remember dun "export" your car to country with 4 season.

normally older car, people use higher viscosity is so that is is better to protect the "wear" engine. also reduce possible leakage.

This post has been edited by brkli: May 25 2022, 11:01 AM

sae40 has HIGHER viscosity I.e. more resistance than 10W40 at 10°C.

and yes, if petronas sell it here, u can be sure it suits our local use. basically we don't need multigrade but it is cheaper to sell it than to create a monograde oil series

I want find ori alternator and power steering pump, all no more. Now all from china OEM. And the power steering rack also mcb, claim few pcs already. gg the labor fee.

Ori 4G parts not cheap. Unless you buy counterfeit mitsu product. That one is cheap.

nothing wrong with mineral oil, just need to change nore often.

Same goes for Wira la....but OEM parts are in abundance. It's your luck. Those days even the Original Proton parts also got manufacturing QC problems. what, you think Ori Proton parts those days are perfect is it ?

That API SF rating is the most concern to me. Many cars in the 90's already require minimum API SL rating and newer engine oil.

there is an iswara in my condo block that is well maintained it could put newer cars to shame
if drive nearby no problem la.

This post has been edited by cempedaklife: May 25 2022, 11:11 AM

Those multi-grade are meant for a range of temperature. Many people instead of more common 15W-40, 10W-40 even go for much more expensive 0W-40. The W stands for Winter or cold temp. The lower the number the colder the temp. When it is cold the oil gets thicker. So, the grade 40 oil will become like 50 or higher thus it is heavy to crank the engine and the oil may not flow easily to protect the engine. So, using multi-grade, you can assume that the oil is like grade 15 when cold (when engine start) and to back to behaving like grade 40 once engine reach normal temp.

In Malaysia, we do not have that big temp fluctuation. So, mono-grade is just fine and save you money as well.