Not at all,take it in. You can often see burning oil by examining the spark plugs. Unless you drive something with a rotary engine,you should not consume oil like that. (I had an RX7 and I had to add a quart of oil with every fill up because there was a little pump on the side of the carburetor that pumped oil into the float bowl. One time it broke so I just put a quart of oil in the gas tank each fill up until I could afford to replace it.)My 3.8 has just turned 4000 kilometers, puffs blue on start up, oil is black, and was down 2 litres after 3500 kilometers. I cannot believe this is normal.