Everyone swears their favorite synthetic oil is the best—but very few people actually put them to the test. So we did. In this video, we compare 10 of the most popular synthetic engine oils using real testing data, including: ✔️ Viscosity breakdown ✔️ Additive strength ✔️ Cold start performance ✔️ Wear protection ✔️ Detergent and cleaning ability ✔️ Extreme heat resistance Some brands performed far better than expected… Others failed shockingly fast—and could be damaging engines long-term. Whether you drive daily, tow heavy, motorcycle ride, or do high-performance driving, choosing the right oil can mean the difference between: 🛠️ Engine lasting 300k miles or 💀 A destroyed engine before 100k. Before you buy another bottle—watch this. 🔧 Subscribe to Cars Guide DIY for honest testing, real results, and zero sponsorship influence. 📩 Business: dyka21129@