Class 8 trucks don't use gas - they use diesel. The capacity of the fuel tanks depends on how it's ordered. A local truck might only hold 100 gallons or so, while a long distance line haul truck might hold well over 300 gallons. For most fleet truck, 240 to 280 gallons is the norm. The truck I'm currently driving (and typing out this post from the sleeper of) has a capacity of 260 gallons.
None. They use diesel fuel, which a North American tractor might hold up to 300 US gallons of (although 250, give or take, is a bit more common).
As much as the fuel tank can hold
The tractor weighs 20,000 pounds, the trailer weighs whatever it weighs, and the maximum weight of a loaded tractor trailer with one trailer is 80,000 pounds.
A ten foot spread axle trailer is allowed 20,000 lbs. per axle, for a total of 40,000 lbs.
Around $60,000, and unless you work for a company you can't buy a separate trailer. $135,000 for a fullsize tractor, $72,000 for a reefer trailer.
It depends on the tractor.
Four to nine MPG, depending on a number of factors. It's pretty much the same with any tractor trailer.
To get the answer, you need to weigh your tractor trailer empty. When you get that weight, Lets talk numbers, this is wrong but it is a big example. If your tractor trailer is 35,000 pounds empty. Means you can haul about 45,000, as long as you are not overweight on your three axles. Steer, Rear, and trailer axles. 12/34/34.
trailer is 70Lx46Wx23H
70khm
If the round about question is how much does a trailer cost then what type of trailer...flatbed, refrigerated, dry van, car hauler, ect. Cost ranges between $30,000 and $100,000. Specialized trailers can be substantially more.
It depends on the commercial vehicle, how it's licensed, the state it's running in, and a lot of other things, but a tractor-trailer combination with tandem axles on the tractor and the trailer can generally carry 80,000 pounds--12,000 on the front axle and 34,000 on the tractor and trailer tandems.