You can buy the additive by itself, to add to regular engine oil, but you can also buy Break-In oil in 1 quart or 5-quart containers. The oil is usually a single grade, like the SAE 30 in my earlier post, but it's also available in multi-grades. I think breaking in (or "running in") procedures for new engines, including the use of special additives, were much more common 50 or so years ago when manufacturing tolerances were not what they are today. And I think just about all the major car and motorcycle companies break in their engines on a bench now before the engine is actually fitted. Happy Memorial Day!