Need to now how many miles It will go.

That's quite a bit, I had a 87 cutlass with a 307 V8 with that many miles, and I sold it; it ran for about another 20-25,000 miles before the original transmission started slipping and the second owner got rid of it. The 3.1 is a very good, durable engine. I assume that you take car of it and perform the required maintenance, oil changes, tune-ups etc. If so, I would not be surprised it went to 300,000 or more. I would, however, prepare myself for any surprises. Meaning if something happened to the car mechanically which would require an investment that is more than the car is worth, ie. slipping transmission, worn engine bearing. So you should have a back-up plan, like money set aside for another car just in case yours suddenly expires. I would say keep doing what your doing and let the car decide for itself. You should get many more thousands of miles out it. Keep us posted. Too bad they don't make Oldsmobiles anymore!

Depending on driving habits, I would expect this vehicle to run up through 300k.

My father passed me down an Oldsmobile Cutlass Supreme that he's had for over 18 years and it currently has 520,000 miles and it still runs smoothly

WOW what year was it and what kind of engine is in it? Any special oil or trick used...