I have a 2006 toyota vitz thats done 190K+ kilometers.
According to online sources, the 1 KR FE engine in my car should be filled with 5w30 grade oil.
However my friend whos very into cars advised me to get a higher grade due to the high mileage.
Should I? And if so, is there some foolproof chart?
Exactly what grade oil should I get?
Higher quality 5w30 oil? Sure. Going to 5w20 or another weight? Hell no. blow up the engine in one go.
Well that’s wrong. Please disregard this person
Oh so you should use the wrong oil then. that’s a smart idea 🙄 by your logic he should use any kind he wants then. Fuck it. Put in 0w10
Ookayyy Thank you everyone
Solved!
Use what is recommended for the car.
No.
Maybe if the engine has worn down a lot a slight increase in oil viscosity might help keep the oil pressure back to the original specification. But even then it would still be something like -40.
Found this image shared from the owners manual supposedly on local forums
The temps here range from 10 degrees Celsius to 45.
Technician here, that chart is trash. Use the weight of oil recommend for your car in the owners manual for it’s entire life.
Only reason to change is to accommodate extreme temperatures and that chart is not at all accurate for a reference in that regard.
Why would they print it if it wasn’t accurate?
Unless the engine is doing something wrong, the recommended 5w30 is what it needs.
There is some truth to changing the viscosity of engine oil as the car ages. That was decades ago. Modern oils and engines are very different. Stick with 5W-30.
Heavier weight oil as the engine ages is an age-old myth. The theory is that heavier weight oil produces a thicker oil film to help piston rings seal better as they age. That’ part has a tinge of truth to it— it does provide a thicker film. But that ignores the downsides to heavier weight oil. Optimal oil weight is based on bearing clearances and using a higher weight oil has negative affects on oil flow through bearings. Using a heavier weight oil actually reduces heat transfer from the bearing clearances. In addition, the internal friction of heavier oil actually creates more heat, which is the last thing you want. So using a heavier weight oil increases engine wear. How much? That depends on how much heavier you go. A switch from 20 to 30 weight is probably negligible. But 20 to 40 would not be good. Use the oil the carmaker recommends, not some self proclaimed oil expert friend who really doesn’t know jack about tribology.
