Is it ok to switch to semi synthetic for old car?

[Albertchristian]

Is it ok to use 10w-40 semi-synthetic diesel oil for 1995 Daihatsu engine that runs 15w-40 diesel API CF-4 conventional oil all the time?
will it harm the engine?

Thanks alot
Albert

 

[daves87rs]

Does it leak or burn oil?

 

[sicko]

I don't think there would be any harm in it, but I'm basing this off the fact that many people switch their high mileage vehicles to Valvoline MaxLife which is a semi-synthetic (also available in synthetic but that's difficult to find).

Similarly, it's safe to switch old vehicles to a synthetic, though the one concern you normally here is that the synthetic might clean deposits that were preventing leaks/burning, and thus potentially cause leaks or burning oil.

Out of curiosity, why are you looking to make a switch? How's it running now, and what do you hope to get out of switching to a semi-synthetic?

 

[Albertchristian]

Yes it burns oil,
usually I add 0.5 liter per 2500 miles
and changed the oil at3500 miles

Thanks

 

[Albertchristian]

Thanks for your answer

basically Im looking for longer OCI and I hope that synthetic oil
will prolonged the engine life with minimizing wear, and maybe a slight fuel economy, because the price between the Semi synth and conventional oil is only slightly different..
What do you think?
regards
Albert