About 6 months ago, my car was using 1 quart for every 1000-1250 miles.
I started using Valvoline Max-Life 20-50 or Castrol High Mileage 20-50.
After 4 oil changes, (I drive a lot from NYC to Raleigh, NC) Can you believe it now uses 1 quart between changes (3000 miles)?
I do not work for either of the 2 oil companies.
Now I believe that oil does help the valve seals.
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car