oil consumption

[boots]

I recently purchased a 1992 Nissan Sentra - only to find out that I have to top up the oil (1quart) every 4-5 days. My mechanic put some "cleaner" in with the oil - hoping to solve the problem - to no avail. Spark splugs are clean, no blue exhaust smoke, and no leaks. My mechanic suggests trying an Esso oil - he says this sometimes works - against all odds. Please help??? Any suggestions or help with what to try if this doesn't work????Thankx. - - boots