.boB

Here's another thought, since you live in WY.

I drive through WY on 80 3-4 times a year. Often in the winter when it's dang cold up there. I have experimented with opening and closing the winter cover. I wanted to see what effect that would have on mileage.

My initial test was between Evanston and Laramie, where the terrain is fairly stable. I did it in December, when the temps were below 0* all day.

I did a second test this January, through Colorado and northern NM.

What I learned was that if the intake charge is too cold, you'll lose mileage.

In WY, keeping the flaps closed provided the best mileage by a long shot. In CO, it was warmer, like 25-55*. I learned that above 45* it didn't really matter. Below that, keeping the flaps closed provided a slight improvement.

I would think a cold air intake would provide a similar result. On cold winter days in WY, you'll lose mileage. Above 40* or so, there's no difference in fuel mileage by changing the intake charge temp.

I think the advantage to a different intake is that it flows a bit more air with less resistance. If you have a bigger turbo and trying to move more air in and out, I can see the advantage to that. Otherwise, the stock components appear to be up to the task, and changing them does nothing for you.

viper67

Diesels run worse when it's cold. Known issue. Whether it's super cold air, or the truck is cold.