I switched to Mobil 1 in my 89 GT with almost 150,000 miles and have had no problems. The timing belt broke on it a few weeks aftarward, but it was ready to go anyway. Synteyic oil is just as thick as regular oil, the only differance is it is more pure.
go here for more info
I don´t know if it´s an issue with the engine seals in a scort, but on some older engines (15-20+ years) switching to synthetic can cause oil leaks. The rubber in some seals gets saturated with all the mineral oil, and then when you introduce synthetics, the mineral oils have a tendancy to get pulled out of the seals. Once this happens the seals shrink up a little bit and the synthetic begins to leak through.
This isn´t a hazardous situation, but can make a clean engine greasy really fast, and you can also end up pouring a couple more cans of that expensive synthetic oil in than you bargained for. Of course.. if they start to leak you can always put dino oil back in and the seals will swell up again. :-] This isn´t common, but something to look out for.
PS: I just got done reading that FAQ on Mobil 1. Apparently they´ve done the job right and made sure their synthetics will keep those old seals conditioned nicely. :-] I´m not sure about other synthetics though. :-?
[ This message was edited by: Beaverboy on 07-04-2003 17:12 ]
What forces on the head will cause a DOHC engine to burn oil??
No engine is desined to or is supposed to leake oil in an amount. If oil is being leaked from ANYWHERE for ANY REASON there is a problem that needs to be fixed. Seals crack for the same reason no matter what type of oil is used. Heat is the #1 reason rubber seals fail, they get cooked and dry out overtime. They then become brittle and the crack. Oil gets into these cracks and erodes them making them bigger.