Originally Posted by cucotx
So around 2007, some regulations came in for diesel engines. A few years later, DEF and other regulations kicked in ...
So what are we dealing with when we buy a new coach with the newer engines?
Do we lose mpg?
Do we lose HP?
I'm guessing they're going to be more expensive to maintain?
Yes to all the above, and add the big YES to the increase in cost just for the privileged of having them hang all the junk on the engines. Yeah, Cummins and the EPA swear the mileage increases and things are all rosy, but in reality, to meet the 2007 EPA requirements the engines were de-rated so badly that the mileage really went into the toilet. Now they give you a small part of that back at the high cost of all the trash they hang, and claim it's such an IMPROVEMENT... Just another line of BS. How can mileage increase when all the extra garbage they've added is in the EXHAUST STREAM---after the power has been extracted from the fuel to drive the engine and coach? The answer is that the engine has not been de-rated as much as it had in the previous iterations, but it isn't what the previous engines were before the EPA started telling us just how great their changes were.