The basic answer: use 5W-30 motor oil that meets API SN/SM/SL and GM’s older 6094M specification; Dexos1 certification is not required for the 2008 model year.
In more detail, the 2008 Chevrolet models equipped with the 5.3-liter V8 (such as the Silverado, Sierra, Suburban, Tahoe, and Yukon variants) typically call for 5W-30 oil. You can choose conventional, synthetic-blend, or full-synthetic oil as long as it satisfies the API level and GM’s 6094M specification. Dexos1-certified oil is common in later years but is not a strict requirement for this vintage; always verify the exact specification on your vehicle’s manual or under the hood cap.
Recommended oil types and specifications
Below are the typical options that satisfy the engine’s needs. Each option assumes a 5W-30 viscosity and compliance with GM’s older specification; choose the one that fits your preference and local climate.
- 5W-30 conventional motor oil that meets API SN/SM/SL and GM 6094M specification.
- 5W-30 synthetic blend that meets API SN/SM/SL and GM 6094M specification.
- 5W-30 full synthetic motor oil that meets API SN/SM/SL and GM 6094M specification.
- 5W-30 Dexos1-certified oil (not required for a 2008 model year, but compatible if your manual allows Dexos1). Always confirm with the manual or dealer guidance.
In short, any 5W-30 oil that carries the appropriate API rating and GM 6094M specification will work well for a 2008 5.3L engine. Dexos1 approval is optional for this year, but using Dexos1-certified oil is acceptable if your vehicle’s documentation permits it.
Practical details
Oil capacity and change interval
The 5.3L V8 typically holds around 6 quarts of oil with a filter change. For conventional oil, many owners follow a 3,000–5,000-mile service interval; with synthetic or synthetic-blend oils, intervals often extend to about 5,000–7,500 miles, depending on driving conditions. Always refer to the owner’s manual or the service sticker for the exact interval and capacity.
Tips for checking and topping up
Check the oil level when the engine is cool and on a level surface. Use the dipstick to ensure the level is between the two marks. If topping up is needed, add small amounts and recheck to avoid overfilling, which can cause foaming and other issues. Use a clean funnel and wipe the dipstick clean before rechecking.
Summary
For a 2008 Chevy with a 5.3L V8, the standard guidance is 5W-30 oil meeting API SN/SM/SL and GM’s 6094M specification. Dexos1 is not required for this year, though Dexos1 oils are compatible if your manual allows it. You can opt for conventional, synthetic-blend, or full synthetic oil; always confirm the exact specification and capacity in your owner's manual or on the under-hood oil fill cap. Regularly changing the oil according to driving conditions will help maintain engine health.