Slightly OT.....Synth & then oil?

TTinCO · Jun 29, 2006

Some bozo gave me a synthetic fill on accident. I've heard a couple people saying to not use regular oil in an engine that has had synthetic in it?

BS?

Presto · Jul 1, 2006

"Once you go synthetic, you don't go back."

Sounds like something the synthetic industry would profess.
Never heard it. I wouldn't worry about it.

CapNCash · Jul 1, 2006

You are supposed to "flush" the engine if you go back to regular to remove the synthetic. I have gone back in forth before without any problems. The theory is that the synthetic sticks to parts more and is more likely to cause rubber gaskets to deteriorate. If you have a newer car I would just stick to synthetic cause u dont have to change but every 10k plus.

BASEHEAD · Jul 1, 2006

Total BS.True its not recommended to mix the two but now even oil companies make a 50/50 mix so go figure. However when they do an oil change correctly ,the vast majority of oil from the crankcase is drained.Even if filled up with synthetic oil wouldnt make a difference as the mixing would be at a minimum.Any car can run on synthetics but if your car is older and has any sort of leakage already it will be magnified b/c S Oil is like water vicosity-wise.Synthetic oil is everything its cracked up to be for sure....Id keep using it.

TTinCO · Jul 4, 2006

It's a 2000 Toyota 4 Runner Ltd with an engine that's tight as a drum.

I had never heard that you Synth only needs to be changed every 10k. That alone makes up for the price difference, so if that's correct, why not stick with it?

CapNCash · Jul 9, 2006

The fact that the oil doesnt break down for 10 or 15k doesnt mean that contaminants, i.e. metal shavings, are removed per regular oil changes. So its a bit of a trade off. If I were you I d stick with the Synth.