A Core deposit is a form of deposit you pay until returning your old part. If you don't have the core at the time of purchase, you must pay the core charge. That charge is refunded to you when you return the core.
Lucas High Performance Synthetic Racing Oil is an excellent product that provides the consistent viscosity needed for precision ET racing. It's blended with an exclusive additive package that includes lubricity agents and anti-seize agents that control drag like a zero weight oil and protect metal like a heavy multi-viscosity oil. It is excellent for normal highway usage.