Mechanic's comment on synthetic oil...

[Drumster]

I had my oil/lube done the other day at my friendly neighborhood JDM sales & service place. We talked briefly about a few things including synthetic oil. He said that while synthetic oils are great for crank bearings & most engine internals, they are actually bad for piston rings. Without putting words in his mouth, my understanding of his explanation is that this is because rings actually require wear & tear to seal properly & remain seated etc.

I don't know - anyone here heard of this before?

[loki]

Without putting words in his mouth, my understanding of his explanation is that this is because rings actually require wear & tear to seal properly & remain seated etc.

I don't know - anyone here heard of this before?

if that was the reason, and it sounds like something I've heard before, it wouldn't apply to a 15 year old engine with close to or more than 100,000 km IMHO once you get to that stage the rings had better be worn in and perfectly seated and sealed. less friction at this point seems like it can only be favourable at this point in the game.

[Manitoba deli]

Synthetic oil is usualy not recomended for the break in period of a new engine, as the piston rings do need to wear into the cylinder walls, after that, synthetic oil is your best friend. An engine will break in with synthetic oil, but it will take a lot longer.

[Drumster]

Comments from each of you make sense to me. I'm at about 58 K right now so not quite at the 100K range but the engine runs like a clock and I'd like to keep it that way for as long as I can. I'm going to stick with my plans to go synthetic.
Cheers!

[Mr. Flibble]

Comments from each of you make sense to me. I'm at about 58 K right now so not quite at the 100K range but the engine runs like a clock and I'd like to keep it that way for as long as I can. I'm going to stick with my plans to go synthetic.
Cheers!

You can go pretty much synthetic after 5000km. And, most new vehicles come with synthetic already from the factory now. Any used vehicle can be moved to synthetic without a problem - UNLESS is is so far gone that the synthetic oil will leak past rings etc. But if that happens, you will know from the bad condition of the engine already.