Hi-po fully synthetic oil OK for 3VZ-E V6?

[headwerkn]

This may well be a dumb question, but I thought I'd better check anyway... is it fine to use something like Shell Helix Ultra in the V6 on my '91? I've always used it in my old Saab Turbos where it has been fantastic (saved one turbocharger that was condemned to die within months) but I have heard the modern fully synthetics can be a bit too slippery for older engines. I know such an oil isn't strictly necessary in a 4Runner but I'm a card-carrying member of the "oil is cheap, engines aren't" brigade.

Incidentally, here in Tassie we don't really suffer from extremes of temperature... at the moment we're in the dead of winter and dropping below freezing overnight is rare... summers occasionally go over 30 degrees C.

Cheers, Ben.

 

[Some1esle]

A 91' I would not put a synth oil in it. Here's why. Over time the seals and gaskets set, get dry, become weak and sometimes it's just the git and grime that is holding back the oil from leaking. If you were to put a synthetic oil in it runs a good chance of doing a bunch of cleaning the grit and grim out. This would give the possibility of the engine starting to begin leaking.
I changes everything in my 95' to synthetic fluids when I got it. It took about 3 days before the oil pan gasket started leaking. After doing some research on oils, I found this to be information. I drained and changed back to dino oil in a flash. I changed the pan gasket, and no leaks since.
So, in short I don't recommend it. It's crazy how guys on this forum will steer so clear of everything but what has been rehashed a million times. Not this poster but those that you normally see giving advice and didn't reply.