Oil Usage Drop (long)
 

Well I assumed I was headed to a top end rebuild due to rather heavy oil usage of around qt/275-300 miles. However, (I hate to admit this) my car had not seen any significant highway driving in about a year...or more. I decided to run a couple of bottles of Techron through it just before and during about 600 miles of highway driving where I kept it in 4th much of the way to keep the rpms up. Oil usage has now dropped dramatically...I added a quart and the level has only moved slightly over the last 350 miles! What could have caused this? Stuck rings...?
Note that I only had occasional puffs of smoke on start up which has also diminished somewhat.
(FYI, I am extremely familiar with how the check the oil)
Thanks,

sounds like good news - you need to drive more!

sounds as though most of your usage was down to oil seeping into the cylinders while the car is parked up.