As of 2012, NACE reported that mechanical engineers with a master's degree started at an average of $75,700 -- significantly more than the average starting salary of $61,300 reported by mechanical engineers with a bachelor's degree.
How many gallons does a semi truck hold? Quick Answer. Semi truck fuel tanks vary in size, but they hold an average of 125 to 300 gallons of fuel. There is a fuel tank located on each side of the tractor, and fuel is distributed between the two tanks to balance weight.
Annual miles driven divided by your truck's average miles per gallon = the total gallons used per year. Do that math. Multiply the answer in Step 1 by the average price of fuel per gallon to determine about how much you spend on fuel each year. Next, estimate how much the modifications will increase your fuel mileage.