GC (stands for German Castrol) is an oil that has plenty of praise here on BITOG. It is Castrol Syntec 0W-30, it will say "European Formula" on the front of the black bottle, and it will say "Made in Germany" on the back of the bottle in small hard to find white print somewhere near the bar code.
This one oil is unique in that it is made by blending 5 percent of a special oil made in Japan that has a weight of about 200. This oil tends to stop consumption and small oil leaks, it holds up well in hot weather and flow well in cold weather. If you look at the specks on Castrol sites you can see that it protects better than their 5W-30 and better than their 10W-30.
Auto Zone and Pep-Boys are the only places to get it.
-------------------------------------------------------------------------------------------------
Some other great oils are Mobil 15W-50 (great for hot weather), Rotella T5 15W-40 (for summer), Rotella T6 5W-40, Mobil TDT (turbo diesel truck), Mobil 0W-40, and Mobil Delvac 1300, or any oil marketed for use in a motorcycle. Most Pep-Boys have a separate section for motorcycle oils.
-------------------------------------------------------------------------------------------------
But probably the best to stop oil consumption would be the GC.
Try GC for about a half hour run, and if it still consumes oil the next thing you would have to figure out is who is going to pull the engine apart to check for things like a piston missing one or more piston rings, (you, a local small engine mechanic, or someone who honors the warranty). It would not be the first engine put together with someone forgetting to put one or more rings on a piston.