It is very sad that you don't know how to make an argument, and respect opinions of others, but instead patronizing them. You, as disrespectful AMSOIL dealer as they can get, is the sole reason I will NEVER buy and use oil that you're peddling. I also change my Castrol Sintec in my little TDI around every 2500 miles. If manufacturer says that this oil is good for 5000 miles, then even better. However, they don’t require this mileage but rather only recommend it. As far as environment is concerned, stop patronizing people and trying to make them guilty of some your BS. Nobody is throwing used motor oil into rivers (maybe in Canada folks do, so that’s why you are getting hardon on everyone that doesn’t think like you, but I doubt it). There are numerous facilities in US, which only business is recycling of used oils and putting them back in service. How such practices justify you calling someone being negligent towards environment? My advice to you: stop patronizing, chill out, and yes breed, and let folks do with their money and equipment whatever they want.