Tittle say it all, I have a 96 Passport with a 3.2 125k, would there be any benefit to going synthetic now. Been on a dino diet all it's life, 5-30 or 10-30, changed every 3k with new filter.

Thoughts, as I want this buggy to last as long as possible.

Synthetics are great stuff, but a total waste unless 1) The engine came with it from the factory & is the 'required' oil, 2) You plan on going FAR beyond 3mo/3000miles with it. 3) you live in arctic cold conditions Below 0degF, or super hot, above 100degF. You absolutely wont hurt anything by switching, by why switch? Looks like your current plan is working great!
G/luck
Joel

I agree. The only hard evidence I've seen is oil analysis done by a guy on the VWVortex forum to see if his synthetic was holding up at 5K. It wasn't. So where's the advantage to using it?

I agree; I don't believe you should switch. I have the same engine, same routine, every 3K - and have the same feeling = want to keep it for a LONG time.

But I am not switching to synthetic; best thing I can do is use good oil, Havoline 10W-30 and Isuzu oil filter.

I have pretty much the same truck. 97 rodeo v6 with 115K. I switched to amsoil full synthetic at about 100K. I made the decision after looking at all the facts on synthetic oil and its protection it provides. I live in Texas and it gets HOT for almost 6 months of the year. The extended drain interval is what I like but have not fully bought into. I have not yet done the oil analysis and may change my mind after I see what the results say. FOr now I am hoping that I can change my oil about once a year and change filters out about every 3 months. I can say that so far it has not changed colors the way my dino oil would. I have been very good about changing my oil every 3K or sooner on a dino diet. It really comes down to how you want to spend your money. It may not really benefit my truck that much but I believe the best lubrication possible is what I want. I hope to get 200K out of the engine.