synthetic is way better for your car as far as I'm concerned, especially in the winter
Thanks for the info on wrist pins! I REALLY did not want to pull the cylinder head.
As far as synthetics, no one disputes their superior charistics- but if you are running an older engine (like my 23 year old 1.6 or my 24 year old 1.6TD)and switch from dino to synthetics, CAUTION. Be prepared for seal leaks. Why? Because your old engine seals are used to running on and being saturated with dino oil, and synthetics can actually cause these old seals to CHANGE - sometimes shrink, sometimes harden, sometimes get way too soft. Which all produces leaks.
You won't see it immediately, but if it happens, you will see it witin 5,000 miles or 12 months.
I switched my 92 TD to synth at it had 430xxxkms on it at the time. No increased amount of leaks. I didn't own it for a year but definitely put well over 5k on it.
It was my understanding that the seal leak was more common with the older synthetics
considering that synthetics are generally thinner, the seal leak theory has some basis... going from a 15w40 dino to a 0w40 or 5w40 synthetic, there are possibilities for leaks, but mainly only when the engine is cold. i believe any oil leak is partially offset by the fact that synthetic oil doesn't burn like dino. if there was no oil leak before, there shouldn't be one after switching. however a small oil leak running thick dino would be worse running a thinner synthetic. hope that makes sense.