Bikeman is right, and that is where your oil's going! Next it will be skipping for the plugs will be fouling out! 
What Could Be Causing Blue Smoke To Come From My Tailpipe?
Ive changed the valve cover gaskets,PVC valve,fuel filter and my car runs good{1994 lincoln town car} but it still has blue smoke coming from the tail pipe
Try this page out it explains the different colors of smoke that can come out of a tailpipe .Www.trustmymechanic.com/troubleshoot_smoke.htm
Blue smoke is the oil seeping by the rings. Thus getting on top of the piston burning up and going out the exhaust. Sounds like the car has many miles on it.This is a sign the motor is worn and getting old.Keep a eye on the oil level and save your money for new ride. Hope this helps . good luck
It is a sign of oil burning. If the power is good it might only be the valve seals. Check the compression by removing the spark plugs and installing a compression tester. These are available at most auto part stores. I had a car that would burry the car behind me in blue smoke after sitting at a stop light. The car was a 1988 Doge Dynasty (Mitsubishi engine). After I pulled the heads and brought them to a machine shop, the car stopped burning oil.
Simple-ring wear.Here's a quick test-go up a hill.If it smokes going up,it's your rings.If it smokes going down(do not give it any gas,just coast)it is your valves.End of story.