I used about a quart between oil changes until about 18,000 miles. I also need about 7 1/2 quarts to hit the full line. I was never able to get a straight answer to whether to use the full line on the stick or the manufacturer's stated capacity. It is actually more harmful to the engine to overfill than it is to be "a little" low. Back in the olden days (40 cent premium), running a half to a full quart low could pick up some free horsepower. The right way would have been to replace the pan with a deeper one. Those days, oil level was checked at every fill up. To have my 70 4-4-2 W30 back, priceless.

 

When I was a kid (back in the stone age of Chevy fuel-injected 427s, Ford 390 "Interceptors", Dodge 440 Magnums, etc.), a state trooper in my county always ran his '67 Plymouth cruiser a quart low. He said it was faster that way. I rode with him a few times (in the front seat). That Plymouth was fast. I saw a certified 145 mphmany times. I believe the speedometer would go to 160.

 

Just thought I would chime in again. I still own the truck and now I have 60K miles on it.

The seals are good, the engine looks clean. No oil slicks in the driveway or the spot at the office.

This was posted in a different thread as well.

I am going through about 2+ quarts, and I mean "+"in 5000 miles. Last round was nearly 1 quart per 1000 miles. That is ridiculous for an engine with 60K miles. I never see oil spots or smell oil in or around the truck. It must be going out the exhaust pipe. Also, coincidentally I have a bad O2 sensor now. Monday I have an appointment to have it looked at. The dealer seemed concerned about the rate of usage. He stated that Chryslers tolerance is about 1qt in 1K miles. That insane as well. I didnt buy a 2 cycle Hemi.

 

Going back to the old technology (prior to electronics), oil consumption not dripped, in the antifreezeor a bad value guide was usually caused by the recycling system of the "polution control loop." You would find the oil in the hose from the PVC valve, in the "air cleaner" or in the intake below the "carb." Today's engines should not use a quart every thousand miles. I'm sure the EPA would state that kind of usage would cause theconverter to fail over time and would definately foul the O2 sensor. The usage you are talking about should definately should up on your plugs. How offen did you replace them and what did they look like?

If you do not get any satisfaction on this trip to the dealer, take it to a good independant. Since you have documented a bad situation getting worse, you want it fixed prior to the experation of your 7/70.

Good luck and do not back down