I am going to change the oil on my w203 C180k using the extraction method. can anyone tell me is it better to raise front or rear of car (park on slope) or leave car on level to achieve the greatest amount of oil from the sump. Will be using 10W- 40 as per dealership on last change. Any suggestions on whether semi-synthetic or synthetic. Only 1500 miles per year.41K on clock. Look forward to any replies.