Good questions. I steer clear of the new emissions engines. They're not as efficient as the older motors. You have a problem with that Def system, you're broke down. Thing is the ultra low sulfur fuel they've been selling since 2007 isn't as efficient as it was before either. That's when they came up with the new engines as well to compensate for the power loss of the old to new fuelI don't own a diesel so this may be a stupid question. But whats the cost of the DEF stuff and how often do you have to add it? And why isn't it just already in diesel fuel at the pump?