I keep on hearing that synthetic oil is bad for an old engine

>>17373213
I have never heard that synthetic can be bad for your engine wtf

>>17373213
it's only bad if you flip from conventional to synthetic repeatedly, and all it really does is leak more and require new seals.

I've heard about this for motorbikes but not cars. The potential issue is that synthetic oils often have a lot of lubricants added, which in a wet clutch bike can make the clutch slip. Don't see why it'd be a problem in a car though.

>>17373240
Basically this. It is thinner and can leak if your seal isn't basically perfect. It can also help remove old sludge from conventional oil, and can cause that sludge to damage other components. Basically, if you use conventional, check all your seals and your filter, since it might get clogged.

>>17373213
>>17373240
>>17373423
Like these guys said.

Only reason I have heard is that because seals tend to wear and the thinness of the oil will leak and/or smoke from the seals.

>>17373213
It depends on how the engine has been treated, OP. If it has been maintained properly synthetic is fine. If not, if it's leaking and burning oil, you probably want to add something like motor honey to the engine and only spend to get the Supertech stuff at Waw-Mart.

>>17373213
Some retard told me it would cause knocking. I got my old car at 83,000 miles where a synthetic blend was used. I switched to full synthetic and did it every 5,000 miles and never had an issue. Sold the car at 106,000.

>>17374976
106k miles is fucking nothing
>83k miles bought
That's fairly lows miles and selling it after driving 20k miles, did you just drive it for a year?