boost??

[20chevy04]

Hey guys so i was driving an 80mile trip with the truck in economy mode the boost pressure at 75mph, just cruising not pulling a load, was at 4-5psi. should i be under any boost when just cruising? it feels my tranny isnt shifting into one of those in-between shifts that lower the rpms.Any ideas or sounds normal?

 

[duramax hd]

Hey guys so i was driving an 80mile trip with the truck in economy mode the boost pressure at 75mph, just cruising not pulling a load, was at 4-5psi. should i be under any boost when just cruising? it feels my tranny isnt shifting into one of those in-between shifts that lower the rpms.Any ideas or sounds normal?

The boost is about right for the mph your cruising at. If I recall, that is pretty much what I sit at just rolling down the road. You have to remember the that your truck weights 7000lbs+ so theres always a decent load on the motor. As far as the transmission question, it sounds like your describing torque convertor lock up. When your not into the throttle to much as it upshifts, your trucks convertor will lock up (feel like an in between shift) at about 55mph. When your more then 50% throttle as it upshifts through the gears, the convertor will lock up in between 2nd and 3rd gear and stay locked all the way through 5th. Hope this helps