Confused on what semi to buy

I found few 2016 Kenworth semi trucks and would like to know which ones have the best mpg. The articles claim the t680 model advantage has the best mpg but I am not sure if the ones I found are t680 advantage. I found 2016 t680 day cabs and 2016 t680 sleeper. I would like to use it to transport heavy freight 2000 miles a week. Is the sleeper going to have lower mpg?

the sleeper details:

Paccar MX-13 6 Cylinder 12.9 L

Ultra Low Sulfur Diesel 455 hp

Engine, 2015 US EPA Label, Requires Diesel Exhaust Fluid,

5295.8 Engine hrs, Air Conditioner, Cruise Control, Power Windows, Engine Brake, Eaton Fuller FRM-15210B 10-

Speed Manual Transmission, Differential Lock, 12350 Ib Front

Axle, 38000 Ib Rears, Spicer Drive Axles, 2.39:1 Axle Ratio,

50350.0 Ib GVWR, Air Ride Cab, 76 in High Rise Sleeper Cab, Bunk Beds, Bunk Heater, Thermo King TRIPAC EVOLUTION Auxiliary Power Unit, Aluminum Outer Wheels,

295/75R22.5, Air Ride

Suspension, 238 in Wheelbase,

Dual Fuel Tanks.


The day Cab details:


2016 KENWORTH, T680, Heavy Duty Trucks - Day Cab Trucks, PACCAR MX-13, Manual, This is a rare find! This is an Off-Lease Vehicle. That means the truck has been maintained properly over its entire life and we have all the documentation and invoices available to the future owner of this truck. How often do you find a truck maintained by a dealership and that has service records from the day it was built? Our financing experts will help you find a financing option that fits your needs, we welcome Trade-Ins, and we can ship anywhere in the U.S. Ask about out Extended Warranties. Please call or visit our showroom for more details. Se Habla Español, 455 Horse Power, AG 400L

Suspension, Aluminum Wheels, 172 Wheel Base, , Axle,

3.7 Ratio,

 

I have a job already making $10k a month and want to try trucking for a year. I found someone to let me use the truck with his MC# to get loads instead of calling brokers that require experience

 

I was looking online and found a flatbed 48-foot trailer to carry heavy load up to 48,000 lbs