---
id: faq-0078
title: "What's the difference between synthetic and conventional oil?"
category: faq
subtopic: service-and-maintenance
page_type: faq
source_url: "https://www.castlecadillacmchenry.com"
tags: ["oil", "maintenance", "fluids"]
questions:
  - "Should I use synthetic or conventional oil?"
  - "Is synthetic oil better than regular oil?"
  - "How much longer does synthetic oil last?"
related: [oil-change, maintenance-schedule]
dealer: Castle Cadillac McHenry
---

Conventional oil is refined from crude and works well for most vehicles, lasting about 3,000 to 5,000 miles. Synthetic oil is chemically engineered to be more stable, cleaner, and longer-lasting-typically 7,500 to 10,000 miles or more-making it cost-effective over time despite higher upfront cost.

Synthetic also handles extreme temperatures better and reduces engine wear. Many modern Cadillacs benefit from synthetic or synthetic-blend oils. Your owner's manual specifies which grade is right for your model.

Castle Cadillac McHenry carries both conventional and synthetic oils in the correct specifications for your Cadillac. Our Service team can recommend what works best for your driving habits and vehicle. **Call (779) 265-4427** to discuss oil options or schedule your next change.