I am going to replace the valve seals in my 103 engine in a couple of months. In the mean time, I have been using Valvoline Max-Life, formulated for high milage cars. The oil consumption has dropped from a quart every 1000 to a quart every 1500 miles. This may help.

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1990 190E 2.6
1996 Grand Voyager 3.3
1985 Mustang GT 5.0 5 SPD
1982 Suzuki GS 750T