Here's what GM has to say about it:

Tech Service Bulletin #01-06-01-011

Information on Engine Oil Consumption Guidelines-

All engines require oil to lubricate and protect the load bearing and internal moving parts from wear including cylinder walls, pistons and piston rings. When a piston moves down its cylinder, a thin film of oil is left on the cylinder wall. During the power stroke, part of this oil layer is consumed in the combustion process. As a result, varying rates of oil consumption are accepted as normal in all engines.

The accepted rate of oil consumption for engines used in the vehicles referenced is 0.946 liter (1 qt) in 3200 km (2000 mi). This rate only applies to personal use vehicles, under warranty, maintained in accordance with the appropriate maintenance schedule, with less than 58,000 km (36,000 mi), or 80,450 km (50,000 mi) for Cadillac, driven at legal speeds in an unloaded (for trucks) condition.

Of several reasons listed, they referred to running at high rpms as one of the factors.

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'99 Z28 A4 BLACK
▪ SLP air lid, K&N filter, air box mod, Borla exhaust
▪ Pioneer DEH-P77DH, Polk speakers

 

Here's highlights of the other TSB:

Bulletin No.: 01-06-01-023

Subject: Higher Than Expected Oil Consumption (Replace Rings)

Models:
1999-2001 Chevrolet Camaro, Corvette
1999-2001 Pontiac Firebird
with 5.7L Engine (VINs G, S - RPOs LS1, LS6)

Condition

Some owners may comment on higher than expected oil consumption. When checked, the oil consumption could be in the range of 400-600 miles per quart (700-1000 km/L).

Cause

The cause for this condition may be an interaction between the piston rings and the cylinder bore in vehicles that are operated at higher RPMs - typically manual transmission vehicles driven in a manner where the engine is frequently or consistently operating at greater than 3200 RPM.

Correction

A new set of piston rings is currently available through GMSPO. The new rings are part of a complete piston ring kit. Install only the number 2 compression ring and the oil expander ring from the piston ring kit. All other rings in the piston ring kit should be discarded. The original number 1 compression ring and the oil ring rails should be re-used in their original positions on the piston. All pistons should be used in the same cylinder bore.

Changing only the piston rings noted, with no change in driving style, should change oil consumption to an acceptable level. Changes in driving style that reduce the amount of time spent at higher RPMs will also positively effect oil consumption.

As like someone posted before, I agree with trying to avoid having the rings changed to correct the problem - unless you were going to upgrade heads, camshaft, etc. Then, it might as well be done.

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'99 Z28 A4 BLACK
▪ SLP air lid, K&N filter, air box mod, Borla exhaust
▪ Pioneer DEH-P77DH, Polk speakers