6.0 silverado using alot of oil.

first determine if it is leaking or being burnt. Look for spots on diveway where you park it or look for blueish smoke from tailpipe. If it is being burnt you will also see oil and carbon on some of the spark plugs. Leaks are usually cheaper to fix. if it is being burnt then you may have an internal leak in the engine or the enigine may need overhaul. Dont agree to an overhaul until they have run a compression test to check condition of the engine. In either case make sure it is taken care of, to you complete satisfaction, before you run out of warranty.