Has anyone had this experience - my engine one day decided to sound differently for some reason - difficult to describe but here it goes: when is engaged, say third, and I start to coast (slowing down), the engine gives a sound like heavy knobby tires on the road. It's not entirely bad and it doesn't affect anything - just louder and a bit more vibrating- but it's just strange that at around 15K miles, with no accidents and no mods, the engine started sounding so differently. I'm going in the dealer later this week to get a faulty brake check light looked at so I may ask them to check this out too.