95 buick uses 2+ quarts of oil in 30-40 miles. there's no smoke, wipe the tail pipe and it's clean. can't see a leak from underneath. runs like normal

To burn that mauch oil without a visible leak or smoke is really hard to believe but if you have no leaks then its burning the oil. Your engine had a problem with valve stem seals and GM came out with new seals.

The oil has to be going somewhere either is running out the engine or burning it!