My engine rolled for the first 100,000 miles without burning/leaking more than 1/2 quart every 3,000 miles (my standard oil change interval). Over the next 125,000 miles, the oil useage varied from the 1/2 quart number to as much as 2 quarts during the oil change interval. The predominant path for oil departure from the engine was the various leak paths that were addressed during the 60K services.
The oil use increased gradually over the next 60,000 miles as the rings and seals aged. I was adding as much as a quart every 800-1000 miles. All of the cam seals were leaking and the greatest leakage path was the rear exhaust camshaft seal. After replacing the camshaft seals during the 60K service at 269,000 miles, the oil leakage was reduced to nearly zero and I no longer needed a catch tarp beneath the engine when parked in my garage.
With no evidence of significant external oil leakage, my seasoned SHO engine now consumes about 1.5 quarts during the 3,000 mile oil change interval. That comes out to about 1/2 quart every 1,000 miles. Quite good for an engine with nearly 300,000 miles and even acceptable for a brand new powerplant.
