how is oil life measured ?
by the condition of oil OR the KM it was used OR Time ?

after turbo my oil life goes down from
NA takes 10000 to go 15%
FI takes 4500 to go 15%..

WHY is that !!

 

im not sure how the computer calculates the oil life. it doesnt change the percentage at all if you are using synthetic vs. conventional.

 

The computer calculates oil life by measuring your RPM's and other information. At least that's how I understand it - not sure what other than RPM, if it does anything else at all.

 

I don't know the details either...but I know cold starts, engine idle time, etc are part of the criteria.



If Felix' turbo installation included a mod to make the mixture richer by making the PCM think the engine wasn't warmed up totally, that would explain the MM's decreased oil change interval. Generally that's a desirable thing as the oil must now lubricate that HOT turbo. More frequent oil changes are a good thing in his case.

On my (older) turbo car, I use Mobil 1 and change it every 3K miles (once a year)...

 

By fuel burned.

 

oil life is calculated by an algorithm using all of the parameters of of the engine: total rpms, coolant temp, load, total running time, speed etc etc.

the way that algorithm works, as in how much consideration is used for each parameter, i don't know.

it makes sense that the addition of the turbo would shorten oil life,
but i wonder if you can trust the oil life system after adding the turbo, one thing that springs to mind is that you now have positive manifold pressure, and im not sure if the computer knows how to handle that, being it was never made to see positive pressure.