toyota Better engine oil for KSP130 over 120,000km milage?

Piumal Kulasekara · August 29

Hi Experts,

I am wondering which engine oil should be a better one for a 1KRFE engine (Toyota Vitz KSP130) which has a 120,000km milage?
So far I have been using 0w-20 since it was the recommended one on the user manual but I've heard from one of the engine mechanic that I should be using 5w-30 since the engine has this higher milage.
So far from the info I gathered over the discussions and the internet (yes the most trusted one 😛 ) 5w-30 is also okay to use since we are in a hot climate and it is somewhat better in lubricating due to the thickness in oil.

But is it the right thing to do now? If I increase from 0w to 5w, then there is no going back to 0w again.

Can someone please help me with this?

TIA

RusT · August 31

If there's no oil burn, best to use the oil viscosity that you have already been using.

iRage · September 1

On 8/30/2025 at 3:56 AM, Piumal Kulasekara said:

But is it the right thing to do now? If I increase from 0w to 5w, then there is no going back to 0w again.

For starters, the W part of the viscosity rating has nothing to do with you, as you do not live in a winter zone where temperatures drop to zero or below. Even if you change from 0w to 5W there is no such thing called no going back.

As for whether it is the right time to change the type of oil...it is highly subjective. If your engine has no oil burning issues, no compression loss, no heating issues, etc...then there is nothing wrong with continuing with 20. But then again if you want to change to 30 it really doesn't matter either.

The ethos behind the move to higher viscocity oils as the engine grows old is with wear and tear the thicker oil will help with heat dissipation, provide more lubrication and offer a bit of fluid resistance (to counter any compression loss). These qualities, even if used on a "fresher" car, are believed to prolong the life of the engine a bit more than using a thinner oil but relieving some stress on the engine. If you move to 30 then it will help your engine dissipate heat a bit better,the thicker oil will not thin out on long drives so it will offer a bit better lubrication and heat dissipation on long drives.

As you may know, manufacturers put 0W-16, 0W-20 and now even 0W-8 to increase fuel efficiency in order to meet emissions regulations (it says so on the manual itself !). Manufacturers recommend a whole spectrum of oil viscosity owners can use on their cars depending on the environment. They ask you to contact your local dealer to get a recommendation on the best oil. So...there isn't anything wrong with going to 5W-30.

Once you do switch you might see a slight drop in fuel efficiency and you might feel that the engine feels a bit heavier (that is the fluid resistance causing some pressure, it is not that the engine has failed). On the other hand if you decide to take a long drive in the scorching heat you will also notice that the engine feels less clanky and is a bit more smoother than when on the thinner oil.