Rolling resistance is highly sensitive to tire pressure. Did you inflate the new tires all the way to maximum pressure?
Its not just the rolling resistance of the tires that kills the efficiency. The air resistance is also a large factor.
You went from 356 square inches of frontal area per tire to 393.
Ignoring the tires being tucked into fenders, you added a square foot of front surface to push through the air. The truck is about 36 square feet to start with, so you added just under 3%.
Air resistance impacts the drag by a factor between the square and the cube of the speed. You can make up for a 3% loss in aerodynamics by driving 1% to 1.5% slower.
Its not just the rolling resistance of the tires that kills the efficiency. The air resistance is also a large factor.
You went from 356 square inches of frontal area per tire to 393.
Ignoring the tires being tucked into fenders, you added a square foot of front surface to push through the air. The truck is about 36 square feet to start with, so you added just under 3%.
Air resistance impacts the drag by a factor between the square and the cube of the speed. You can make up for a 3% loss in aerodynamics by driving 1% to 1.5% slower.
