2004 ZR2 Break-in (gas milage)

What is the normal break-in time for a vehicle? I've had my '04 ZR2 for about a month now and gets 15-16 miles per gallon highway. This is terrible. I have about 2200 miles on it and I was hoping after 2k I would see improvement, but no such luck.

These blazers are Known for their terrible gas mileage Dont expect more than 17 or 18 city

Ron

Yip, you will notice mileage like this until is fully breaks in at aroun 5000-10000miles.

After taht, switch to 5w30 Mobil 1 synthetic at a 8000mile change interval.

blazers have the worst gas mileage, there is not much u can do to get it any better.

Yea, they are incredible heavy vehicles and weigh in at 2 tons.

Lot of weight in a small package.