Decrease in mileage and increased boost
I have noticed my E99 has been getting lower mileage than normal lately. My mileage has dropped from 15mpg to the mid 13's (hand calculated.) I have also noticed that while cruising at 60mph, I am seeing increased boost. Currently at 60mph I see 5-6psi. I used to see 3-5psi. WOT boost of 27psi has not changed.
I have lifted the truck with the transmission in neutral and the wheels spin freely.
I have AE and do not have any codes. I replaced the EBPS and tube within the last 6 months. I do not see any boost or exhaust leaks.
This is my first winter with a 7.3.
Could the mileage/boost changes be due to winter fuel and 30* temps or should I keep looking for more issues.
Suggestions would be appreciated.