How does aerodynamics affect fuel efficiency

Find Near Me. Enter a Postal Code. We are currently experiencing technical difficulties. Please wait a few minutes and then try again. Back to Articles. Ever made a paper airplane? Why it matters to your commute At high speeds, these competing drag and lift forces can make objects act in erratic ways — not exactly ideal for highway driving.

Go to front page. Search results Search Haynes. Year Year Make Make. Model Model. Here are a few of the things makers do to improve the airflow, some of them surprising. Car Buying. Recommended for you. When is the best time to buy a car? Log into your account. Forgot your password? Create an account. Sign up. Password recovery. Recover your password. Friday, November 12, Get help. The GoMechanic Blog. Nothing in the automotive world is ever actually free, and getting the aerodynamics right requires many hours of research, using some very expensive equipment.

A moving vehicle has to push air out of the way, and it takes fuel to do that. Engineers measure this air resistance as coefficient of drag Cd , and a vehicle with a low Cd is more aerodynamic than one with a higher number.

By comparison, a square-styled sedan from the s could be close to 1. The most aerodynamic car possible would be a low-slung, teardrop-shaped, completely smooth vehicle not much wider than its occupant — great for setting fuel-economy records, but not really big on practicality.

Instead, engineers have to work such with such realities as cabin volume, ground clearance and engine cooling. When the initial design is set, it goes to a wind tunnel, usually using a clay model or mock-up. These are generally full-size, but smaller versions have their place.

Anything that takes away from that super-smooth ideal needs to be considered, such as door handles, windshield wipers and roof gutters. Engine compartments can also be problematic. Air has to flow in to cool the engine, but it also increases resistance when it pushes against the firewall.