This is mostly in regard to Mobil's Clean 5000/7500 and Extended Performance. Does anyone else besides myself see their advertising as flawed? Don't you they they should really be advertising "will last up to 5000" "up to 7500" and "up to 15000".... Not Guaranteed to X number of miles. Because everyones driving condtions and climates are different and ever changing. I guess in some ways they do state what they consider severe service and not to drive up to the guaranteed mileage under those conditions, but it still seems to mislead the consumer and I wonder when it will come back to bite them? I'm eager to see or hear when people begin to make claims they drove the "guaranteed" mileage and toward the end of their engines life, they find it all sludged to #@$%! and back.