It is either burning oil or leaking oil to use 6 quarts in 300 miles. In fact to loose 1 quart every 50 miles you would see lots of smoke. So if you see no smoke then it is leaking. No other explanation.
White smoke from the exhaust when the engine is warmed up indicates that engine coolant is getting into an engine cylinder from a bad head gasket , a warped or cracked cylinder head - sorry
It sounds like engine coolant is getting into the engine cylinder
If you are getting white or grey smoke out of the tailpipe , especially when the engine is warmed up , you have coolant getting into an engine cylinder from a bad head gasket or warped or cracked cylinder head
Sounds like engine coolant is getting into an engine cylinder
If white smoke is coming out of the exhaust when the engine is warmed up , it sounds like engine coolant is getting into an engine cylinder
If the check engine light is blinking , that indicates a cylinder misfire has been detected White smoke coming out of the exhaust ( especially when the engine is warmed up ) indicates that coolant is getting into an engine cylinder from a bad head gasket , a warped or cracked cylinder head
I have checked the oil pan and the cylinder cover gaskets and they are fine, the leak seems to come from the passenger's side of the motor, some of it is being burned but not enough for there to be smoke from the tailpipe. I cannot see any active leak or spray when the engine is running, but it has a steady small drip. I am loosing about 2 quarts/week, which is too much for an engine with only about 100K miles on it.
Blown cylinder head gasket. The engine burns water.
White smoke from the exhaust is a sign of coolant entering the combustion chamber. With the excessive oil usage, it sounds like this engine has been destroyed by this coolant. It has mixed with the oil, and has ruined the engine. Time for an overhaul.
Blue smoke = Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. Black smoke = Black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Another term for excess fuel is "running rich." White Smoke = White smoke is caused by coolant entering the cylinder, and the engine trying to burn it with the fuel. The white smoke is steam. Warning: If you see white smoke, stop driving this car immediately. Severe engine damage will occur if you continue to drive this vehicle. You have severe engine problems as in a blown head gasket or cracked head.
Black smoke= rich condition(too much fuel and not enough air). Blue smoke = burning oil(engine components excessivly worn). White smoke= possible blown head gasket. Check oil to see if coolant is mixing in. Also check coolant level to see if it is loosing it. Have cylinder compression test done to verify head gasket problem. Other possibilities are a cracked cylinder head or engine block.
If the engine has done high miles, check for how much oil is in the air filter hose to the inlet to the motor. You could be using it here as it mixes with the fuel in the motor.