i have 1990 mercury marquis i drove 800 miles low 1 3/4 quarts of oil does this hurt my engine

in the long run yes. any time you run your motor low on oil or are not prompt on your oil changes there is unwanted friction inside your motor that will take away from the life of your motor. chances are you may never see the results on a car that age something else may happen first or you may end up selling the car. the real question is..where is the oil going?

yes.oil not only lubes but cools ur motor,,,new engines dont take kindly to abuse.but dont worry about it.just keep eye on oil and all fluids

yes it will after a while, just what ever you do DO NOT OVER FILL IT it can blow your gaskets

As long as there is enough oil in the crankcase, it doesn't

Yes it does-it makes it use oil even faster than it does and will lead to engine failure.At the rate you are losing oil you should check it at least every 500 miles and never let it get more than 1 quart down.

Technically no. As long as you still have oil pressure then you are getting the same amount of oil to the moving parts. The worst part is the amount of metal particals and trash per quart of remaining oil is alot higher when the oil is low and passing through the filter. Ok let me jump on the others bandwagon here, instead of getting 5,000,000,000 miles out of your engine now you will only get 4,999,999,999mi. out of her.

No. Low on oil does not mean dangerously low. There is enough oil in the motor. Just fill it back up. But no, it does not hurt your engine.