How much more fuel is consumed when driving at 70 mph compared to 50 mph?

Answer: C — 30 percent more fuel

Driving at 70 mph compared to 50 mph generally results in significantly increased drag and other aerodynamic forces acting on the vehicle. The relationship between speed and fuel consumption is not linear; as speed increases, the resistance against the vehicle increases exponentially, leading to higher fuel consumption. Studies have shown that for many vehicles, fuel efficiency can decrease dramatically at higher speeds, often cited as being around 30 percent more fuel used when traveling at 70 mph versus 50 mph. This significant increase can be attributed to factors such as wind resistance and the engine working harder to maintain higher speeds.