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.
TriShield is a unique triple-action technology that attracts, captures and disperses particles that can build up in engines and causes sludge build-up. TriShield stops small particles from becoming big problems, and protects the car you rely on. This innovative technology uses a polymer that contains two chemical hooks that attract and capture both sludge and soot in a single molecule, helping to prevent particles from building up. With TriShield Technology, Castrol has improved the potency and protection that GTX provides.
Unique TriShield technology actively protects against particles that build up in car engines with the most advanced sludge-fighting ingredients
Castrol GTX uses premium, custom-made additives and is the most advanced conventional oil available
Maximum protection against viscosity and thermal breakdown
Formulated to exceed engine protection requirements of Ford, GM, and Chrysler Corporation