The answer options
- Around 15%Correct
- Around 40%
- Around 30%
- Around 5%
Why that is the answer
Driving at higher speeds greatly increases aerodynamic drag, forcing your engine to work much harder to maintain momentum. According to official DVSA guidance, driving at 70 mph uses around 15% more fuel than driving at 50 mph. While drivers often overestimate the extra consumption at 30% or 40%, or underestimate it at 5%, 15% is the accurate average. Easing off the accelerator saves fuel, lowers emissions, and keeps your vehicle running costs down.
How this comes up in the real test
Questions from safety and your vehicle appear throughout the 50-question multiple-choice section, and the wording changes between versions. Learn the rule rather than the sentence: the DVSA can ask the same point from the opposite direction, and a memorised answer falls over the moment the phrasing moves.
The pass mark is 43 out of 50, so seven wrong answers is your entire margin. If a whole category is shaky, run the topic practice below until you are getting every question right for the right reason, then go back to full mocks under the clock.
More safety and your vehicle questions
- A vehicle MOT test will include an exhaust emissions test. What is the reason for this?
- Before leaving your vehicle unattended, what should you remove from it?
- How can drivers help the environment?
- How can driving in a fuel-efficient manner help protect the environment?
- How can the volume of traffic on roads be reduced?
- How can you avoid wasting fuel?