Understanding Dexos oil: The Standard for GM Engine Oils
Learn what makes Dexos oil different and why you must use it in GM vehicles
For owners of General Motors (GM) vehicles, using the right type of engine oil is crucial for maintaining optimal performance and protecting the engine from premature wear and tear. GM has developed a proprietary oil specification called Dexos, which is designed specifically for use in their vehicles. Understanding what Dexos oil is, why it’s different, and why it’s important to use it can help ensure your GM vehicle remains in top condition for years to come.
What is Dexos Oil?
Dexos is a unique oil specification developed and licensed by GM. It is not a brand of oil but rather a set of stringent requirements that motor oils must meet to earn the Dexos certification. The Dexos specification covers various performance criteria, including oxidation resistance, aeration control, seal compatibility, and protection against low-speed pre-ignition (LSPI), a potentially damaging phenomenon that can occur in modern turbocharged engines.
Why does GM need a different oil specification? What was wrong with the old one?
GM felt that the existing oil specifications didn’t work well with their engines. Oil manufacturers have had to reduce the amount of zinc wear additives due to zinc’s propensity to damage catalytic converters. GM felt, that with their “cutting-edge designs”, such as direct-injection systems, turbochargers, and advanced emission control systems, they needed a different oil.
The Dexos specification addresses these demands by requiring the use of specialized additives and base oils that can withstand the higher temperatures, pressures, and stresses found in GM engines. Additionally, Dexos oils are designed to enhance fuel efficiency, reduce emissions, and provide improved wear protection compared to conventional oils.
How importance is Dexos Oil in GM Vehicles?
• Void your GM powertrain warranty — Not using the recommended oil can void your engine warranty
• Timing chain and camshaft wear — Not using Dexos oil can result in additional timing chain can camshaft wear.
• Lower fuel economy — The oil is formulated to reduce friction and enhance fuel economy, so you may suffer fuel economy if you don’t use the recommended oil
• Emissions Compliance — Dexos is designed to work seamlessly with GM’s emission control systems, ensuring that the vehicle remains compliant with environmental regulations.
The two types of Dexos oil
Dexos™ 1 is for gasoline engines meeting ILSAC GF-5 Resource Conserving specifications. This has recently been updated to Dexos™ 1 GEN 2 for even better engine protection particularly against LSPI (Low Speed Pre Ignition) in GM vehicles.
Dexos™ 2 is for Diesel and some gasoline vehicles and meets Low SAP requirements* for vehicles fitted with exhaust treatment devices such as DPFs (Diesel Particulate Filters).
©, 2021 Rick Muscoplat
Posted on by Rick Muscoplat