The 2014 E350 requires synthetic engine oil that meets Mercedes‑Benz specification MB 229.5 (and MB 229.51 in some markets), with common viscosities around 5W-40 and, in very cold climates, 0W-40.
For the 2014 E‑Class E350, the oil specification is tied to the manufacturer’s long‑life service plan. Using an oil that does not meet MB 229.5/229.51 can affect engine performance and warranty coverage. The following guide outlines the official recommendations and practical tips for selecting the right oil.
Official oil specifications and viscosity
Merced es-Benz specifies a fully synthetic oil that meets MB 229.5 (LongLife) – with MB 229.51 accepted in some markets – for the gasoline engines used in the 2014 E350. Viscosity choices depend on climate, but the typical baseline is 5W-40; 0W-40 is allowed in very cold environments. Always confirm on the bottle and in your manual.
- Specification to look for on the oil: MB 229.5 (and MB 229.51 in certain markets)
- Viscosity options: commonly 5W-40; 0W-40 suitable for very cold climates
- Formulation: fully synthetic motor oil; avoid conventional/mineral oils
- Service interval context: aligns with Mercedes’ LongLife service schedule (varies by market and vehicle usage)
In short, choose a fully synthetic oil labeled MB 229.5/229.51 with a viscosity of 5W-40 (or 0W-40 in cold climates) and follow the vehicle’s service plan.
Practical oil choices and where to buy
To make purchasing easier, look for well‑known brands that explicitly certify MB 229.5/229.51 compatibility. These oils are widely available and designed to meet Mercedes‑Benz testing and warranty requirements.
- Castrol EDGE 5W-40 (MB 229.5/229.51 compatible)
- Mobil 1 ESP 5W-40 (MB 229.5/229.51 compatible)
- Liqui Moly Synthoil Longterm 5W-40 (MB 229.5 compatible)
- Motul 8100 X-clean 5W-40 (MB 229.5 compatible)
Brand availability can vary by region, so always verify the MB specification on the oil bottle or the retailer’s product page before purchase.
How to confirm the exact oil for your car
Because regional variations exist and engine revisions can change recommendations, verify with the manual and a trusted dealer or technician.
Check the owner’s manual and the engine oil cap
Consult the owner's manual for the MB 229.5/229.51 specification and the recommended viscosity. The engine oil cap on many Mercedes models also indicates the standard (for example, 5W-40).
Consult a Mercedes-Benz dealer or certified technician
If you’re unsure, contact a dealer or a qualified technician to confirm the oil specification for your exact VIN, engine variant, and climate.
Summary
For the 2014 E350, use a fully synthetic oil that meets MB 229.5 (and MB 229.51 in certain markets), with a typical viscosity of 5W-40. In very cold climates, 0W-40 is acceptable. Always verify the specification on the bottle and in the owner’s manual, and rely on Mercedes‑Benz technicians or dealers if in doubt. Adhering to the MB 229.5/229.51 standard helps maintain performance, efficiency, and warranty coverage.
Overall, the key takeaway is to use a MB 229.5/229.51‑certified synthetic oil at the recommended viscosity, with following the vehicle’s service intervals to ensure optimal engine health.