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.
Mobil Super Synthetic 10W-30 is a full synthetic engine oil designed to help extend engine life in vehicles of all ages. 10W-30 is the viscosity recommended for many vehicles manufactured before the year 2000. Mobil Super Synthetic 10W-30 helps extend the life of your engine by protecting engine parts from high temperatures, sludge buildup, and wear.