2011 Ram only averaged 15.3 mpg on highway trip?
I've got a 2011 Ram Laramie 5.7 Hemi 4x4 with 17k on it. I've owned it since new, but this was the first time I've taken it on a road trip of any distance. To my surprise I only got 15.3 mpg on the interstate according to the display on the dash. Did the speed limit all the way, which averaged between 60/70 mph, Two adults. I do have a regular tools box, but isn't super heavy.
I thought this truck is suppose to get around 19 mpg on the highway? I'll admit I was running Walmart gas with 10% ethanol, but 15.3 mpg seems way off, and I'd think it would get better mileage than this. Any suggestions how to improve this? I've always kept it serviced at the dealership.