You can tell it's there at times. They still in my opinion oil up a little - nothing like a "traditional" two stroke in that it will quite happily do 8 hours at idle towing live baits but has a stumble for a second or so when you give it the beans until the oil burns off. Personally I prefer the smell of the old school oil over the XD100 but it's not bad enough to worry myself. All that said mine is a 2006 model. There have been changes to injectors and mapping since.