This one has me puzzled and I need some help. My 99 4 cyl Camry doesn't use any oil between oil changes every 3-4000 miles(I do it myself) when its just local driving or 200 mile trips around the state. But when we drive to the midwest -2 day trip - interstate all the way
- driving 65 to 70 mph steady -1200 miles one way - sometimes I use a quart of oil and sometimes I dont use any. We've made at least 10 trips. I cannot see any oil leaks and the exhaust pipe is not black with carbon buildup. I took it to the dealer when it was still under warranty and they coudn't find anything wrong. Other than that I have had no problems with it. Any ideas?