by P Sanchez
Whether it's about counting pennies with every trip at the pump, or being legitimately concerned about the environment, saving on fuel is practically on everyone’s mind. Sure, the government already has in place strict emissions laws for manufacturers to follow (which makes for ever-more fuel efficient vehicles), but you are wondering how much you can do to make the EPA of the car you already have, better.
We’re not going to talk about aftermarket gadgets and gizmos that claim will put 50 more horses for just $15 (I’m looking at you Turbo Air Intake Gas Fuel Saver Supercharger Fan) but practical tips that won’t cause you a dime but have real-world benefits.
Keep your Tire Pressure Up
A favorite tip among car experts is keeping your tire at the OEM recommended air pressure. This practice has a host of benefits, not the least improving fuel economy. According to the Department of Energy, every 1 PSI drop from the recommended tire pressure lowers the gas mileage by 0.4%.
The percentage seems trivial but consider how difficult it is to judge how under-inflated your tires are without the proper tools. A tire that’s only at 22 PSI looks almost the same as one in 32 PSI, and that’s already a 4% inefficiency on one tire.
Keeping the tire pressure right also means making your tires last longer because under-inflating or over-inflating tires will cause uneven tire wear which will shorten the tires’ service life. Additionally, since it takes more energy to move a car with under-inflated tires, this translates to undue stress to your cars’ wheel bearings, axle joints, transmission, and engine. Tires cost a few hundred dollars per piece, engine repairs a few thousands.
So remember to have your tire pressure checked once a week at your local gas station or auto repair shop (or purchase your own pressure gauge since they’re relatively inexpensive). Quick Tip: You can find the information about the recommended tire pressure for your car near the door latch of the driver-side door or under the hood.
Improve Your Aero
I don’t mean doing eco-modding extremes like grille blocking, adding wheel skirts, or constructing boat tails. Sure, those modifications work especially if you’ve got a knack with fiberglass-making and you don’t mind the odd looks but we’re talking about more practical things you can do. And when it comes to improving your car’s aerodynamics, you can do two simple things: roll-up your windows and lose the roof rack.
Wind resistance increases exponentially with vehicle speed and at over 55 miles per hour, most of your vehicle’s effort goes into overcoming the wind. At 65 mph, estimates show that wind resistance uses 90% of your car’s energy even if it’s a sleek modern sedan. An open window increases a car’s drag coefficient by 20% more so you actually save more gas keeping all your windows closed at highway speeds, even if it means using your car’s power-sapping AC.
According to fueleconomy.gov, roof racks and luggage containers cause additional drag and lower fuel economy by at least 2% in city driving and as much as 25% on the highway. In fact, any protruding part of a car that interrupts the flow of air around the vehicle will contribute to drag. These would include side-mirrors, windshield wipers, outboard radio antennae, and even spoilers (at least the ones installed for “show”). So shelf the rack until your once a year vacay.
Stop Driving Like a Maniac
The last practical tip to increase fuel economy is changing the way you drive. Experts agree that driving conservatively brings the highest improvement in fuel mileage and promotes a longer service life from your car.
It is known that rapid acceleration uses more gas than slower acceleration for the same mileage. The faster you want to overcome inertia, the more force is required, therefore more energy. It’s simple physics. In the operation of your car, this means lingering at the higher rev-range of your engine which uses a lot of gas. Rapid deceleration and braking also decrease fuel economy by wasting a lot of the fuel-fed motion to heat.
All these rapid fluctuations in vehicle speed can increase fuel consumption anywhere from 20 to 50%. Staying in the lower rev-range and getting up-to-speed through proper gearing of the transmission saves the most gas as well as coasting to a stop or slower speeds.
At slow speeds, you’re probably revving the engine too much at low gear, while at really high speeds you’re fighting against the wind. Experts say the sweet spot is keeping a consistent speed between 30 and 50 mph as much as possible.
If you’re not in a big hurry, ease off the gas pedal. Besides, how much time are you really saving overtaking cars and doing jackrabbit starts? Plan your routes, leave early and cruise the highways. Your car, as well as your wallet, will thank you for it.