I'm new to the diesel world but I'm loving the new power. My question is about fuel mileage and how cold weather changes it. during warm weather, 70 to 90 degrees i was getting between 19 to 21 MPG now that the temps are staying between 25 to 45 my mileage is down to about 16 to 19 mpg. I have kept up with service, oil,trans, fuel filter and a K&N air filter. Should I run the cold weather cover to keep up the engine and trans temps or should I check for other problems.
Thanks
