The Buick LaCrosse generally uses Dexos1 Gen 2 approved motor oil, typically 5W-30, with variations by engine and model year. Older 3.8L V6 models often accept conventional or synthetic 5W-30. Always check the owner’s manual for your exact specification and capacity, but most LaCrosse engines take about 5 quarts with a filter.
Oil type by engine
3.8L V6 (2005–2009)
The 3.8L V6 that powered early LaCrosse models typically requires a standard 5W-30 oil, which can be conventional or synthetic. Dexos1 certification is not strictly required for this older engine, but using a Dexos1- or Dexos-compatible oil is acceptable. The oil capacity is about 5 quarts (4.7 liters) with a filter.
Commonly approved oil options for the 3.8L engine include the following:
- Conventional 5W-30
- Synthetic or synthetic-blend 5W-30
In practice, either option provides adequate lubrication; follow the maintenance schedule in your owner’s manual and use a quality oil filter.
3.6L V6 (2009–present, including later LaCrosse models)
The modern 3.6L family in the LaCrosse requires Dexos1 Gen 2 approved motor oil, with 5W-30 being the standard viscosity in most markets. This can be a synthetic oil or a synthetic blend, depending on climate and driving conditions. The oil capacity is typically around 5 quarts (4.7 liters) with a filter.
Recommended oil for the 3.6L engine:
- Dexos1 Gen 2 5W-30 (synthetic or synthetic blend)
Always verify the exact specification in the owner’s manual or with a Buick/GMC service advisor, especially if you operate the vehicle in extreme temperatures or under high-mileage conditions.
Oil-changing considerations
Adjacent to the oil type, consider the change interval and quality of oil. Synthetic oils typically allow longer drain intervals than conventional oils, often up to 7,500–10,000 miles (12,000–16,000 km) under Buick recommendations when the vehicle is primarily highway driving and the oil is Dexos1 Gen 2 approved. In severe service or with older engines, shorten the interval and use the grade recommended by GM in your manual.
Summary
For most Buick LaCrosse models, use Dexos1 Gen 2 5W-30 oil, with 3.6L engines leaning toward synthetic or synthetic-blend formulations and 3.8L engines accepting conventional or synthetic 5W-30. Confirm the exact specification and capacity in your owner’s manual, but plan on about 5 quarts with a filter for a typical oil change. When in doubt, consult a Buick dealership or trusted technician to ensure you meet GM’s current recommendations.