make sure not to use conventional oil in your car. My dad had to do a major service on his 2002 passat 1.8T recently because sludge had built up in the pan and clogged the pickup causing lower oil pressure which threw a CEL for the timing tensioner. he said according to the mechanic and VW vortex boards, synthetic is always recommended in those motors. His car has 85k miles and the oil was religiously changed every 3,000-3,500 miles but was never converted to synthetic. he said they switched him over to 10w-30 synthetic.