I have a 07 mega cab 2500.installed 5" exhaust and and larger air box , it has stock tires and 3.73 rear axel.
this truck gets 14---14.5 hand calculated highway miles per gallon solo. Is this normal milage for this truck.Thank you for your help coffee cup

 

I get 13mpg with my camper and the equivalent of 4.10's with my G-56.
Stock exhaust and intake+ Smarty which does nothing for the mileage.
I think you're a few mpg's shy.

 

OP, you didn't indicate your speed. But yep, that's about right if your on 265s, 373s and 72+mph

With these trucks, fuel efficiency goes down with rpm/speed. There's a sweet spot but anything over 2000rpm and you start getting some negatives. Also driving conditions matter, like cross, head or tail winds.

Driving for efficiency takes discipline too, it isn't all truck.

I get 13-15city. 16-19hwy. My combined avg after 85k miles is 16mpg.

 

Makes me cherish the two injection event early '04. I get 19-22mpg. Optimum speed is 50 mph 1800 rpm. At 75mph, I see 16-17mpg.

 

I'd say that's low if that's average driving conditions on your stock tire truck.
I get 18 +/- mpg mixed city and highway summer driving, with a tune. That includes some 70-80mph freeway stretches and equal amounts of stop n go. This commuting is in the low 18s.
This is currently off the overhead display which was pretty close to actual last time I calculated it with bigger tires.

Haven't taken a road trip without a trailer in a long time, but I recall around 16 if cruise is on 80mph.

 

Those high psi 22's probably too!

 

It's funny how those tires work. They are wider than the original tires by about an inch. I run higher tire pressure than the 17s. I get worse mileage at lower speeds than the originals, but marginally better at highway speeds. I get MUCH more traction under all conditions with those tires. Tire wear is almost non existent. I never run the Alcoas in the winter, the salt will kill them.