What oil should I put in my Smart Fortwo or Roadster engine?
Smart and Mercedes dealers in the UK seem to use Mobil One, which is a fully synthetic oil available in grades such as SAE 0W/40 and 5W/40 fully synthetic. The oil that is recommended by Smart gmbh in Germany is SAE 10W-40. This isnt commonly available, as the winter ratings of most synthetic oils are now lower. We recommend you use a good quality synthetic oil with a specification close to SAE 10W-40, although we have run our remanufactured engines on semi-synthetic oil of the same grade, for many thousands of miles, without any instance of failure. The quality of the oil, and the frequency of the oil change, is very important. We suggest the oil and filter should be changed every 5000 miles. (Please note: the above oil viscosities are based on the UK climate, but they should also be good for other areas where the outside temperature is in the range from 25 degrees down to minus 20 degrees Celsius).
