Volkswagen Repair: Oil Burner, head gasket, weight oil

Question
My son has a 91 Passat.It has 124,000 miles on it.Just an older used car I got for him.This thing doesn't leak any oil but it sure goes through it.About a quart every other day.It doesn't smoke and you can't smell oil burning.But he told me that he noticed that in the rearview mirror he has seen a cloud of white smoke once.A big cloud of it.But it clears up and he doesn't see it again.I know the rings and valve seats are probably a little worn but to lose this much oil I would think it would have to do with this white cloud of smoke he mentions.It's a standard shift,he asked me if I thought maybe there was a product that he can put in to maybe curb some of the oil burning,told him I would check with you.Lotta miles, and a cheap car wanting to get some more time out of it without major engine work.Thanks,
Larry

Answer
Well, your right, that is alot of oil to burn. But, how many miles do you drive a day. I will asume that you don't drive that much. Check your spark plugs, with that much oil being burnt, there is bound to be residue(black oily)on the spark plugs. If not, the oil has to be going somewhere? You better hope that you haven't blown a head gasket. Check your cooling system for creamy looking coolant. You definitely can buy some heavier weight oil so that it doesn't burn as fast. They do make special oils for "higher milage vehicles" that also don't burn as fast. Check your parts store.