How to Use Castrol 5W 50 in a Mercedes Benz E 320

1. Determine the temperatures at which you'll be operating the Mercedes E-320. You can use any viscosity oil between freezing point (32 degrees) and 86 degrees or higher. If you plan to use the vehicle at temperatures below 23 degrees, do not use SAE 20W-40 or SAE 20W-50 oil.
2. Use SAE 15W-40 or SAE 15W-50 at temperatures down to 5 degrees, but not lower. Use oil with a SAE 10W rating down to about -4 degrees. Use the Castrol 5W-50 down to -13 degrees. You can also use SAE 5W-40 and SAE 5W-30 at that temperature.
3. Don't use Castrol SAE 5W-50 if you will be operating the Mercedes E-320 below -13 degrees. Use an oil with a SAE 0W classification, like SAE 0W-30 or SAE 0W-40.