Hey Guys,

My 2007 Colorado just passed 200k miles. Never used oil. It is the 4 cylinder. Last oil change, I drained all 5 quarts out just like always before, filled it up with Pennzoil High Mileage with filter, and 2000 miles later it is 2 quarts low and the oil light coming on. Changed the oil again and went with thicker oil, 10w 40 instead of the 5w 30. Now at 500 miles later its a quart low.

There is no smoke at startup.
There is no smoke when running cold or hot.
There is no oil leak in the drive way.
No oil anywhere on the motor.
Pulled all 4 plugs, all 4 look exactly the same, dry and a dusty brown.
Coolant is clean.

Could it only be leaking at high rpms on the highway?
Losing that much that quick, I should see some evidence somwhere, shouldn't I?

Thanks,
Bo, Houston, TX