What is best cruising speed on highway with D/A?

[QUIKAG]

My brother finally picked up his truck and loves it.  He's really interested in getting the hyped much better mileage than he was getting with his old 5.3L 1/2 ton Z71 pickup.  Anyway, what is the best cruising speed on the highway with no weight in the bed and nothing being towed?  Is there a best speed to cruise at.  He said at 90mph it was quite a ways up the 3200rpm tach.  

[Shaners]

I'm sure 90 MPH isn't the best cruising speed to get good MPG's.

 

I would think that 65-70 MPH would be fine for seeing the upper teens in the MPG dept...  Remind your brother that he won't be seeing those good numbers until there is at lest 5-10K miles on the odometer...

[SoMnDMAX]

About 1800-2000 RPM, or 60-70 MPH. Any higher and mileage will drop off greatly, at least for me.

 

60-70 MPH MPG = 20-22

70+ MPH MPG = 17.5-19.5

 

[BlackSilver]

Mine seems to like the mid-60's the best, either empty or towing.

[QUIKAG]

Thanks for the input guys!  He said he got about 17mpg on a 400 mile road trip.  Of course, he was going 80+  

[odoh]

Mines best @ 1850/55mph. However, when so doing, beware of road rage