Fuel-Efficient Driving Tips

It often costs nothing more than modifying your driving habits. By doing so, you might save some 20 per cent on your fuel bill.	Minimal effort required – often just easing up on the gas and brake pedals.	You could reduce your emissions of greenhouse gases and pollutants by about one tonne per year.

Here’s some good news.  You can do something about fluctuating vehicle gas prices. No, it doesn’t involve abandoning your vehicle, though of course the best gas-saving solution is to drive less.  Even a hulking SUV, if driven infrequently, will consume less total fuel than a compact hybrid always on the go.

Still, there are a number of on-road actions you can take that, collectively, will significantly reduce your fuel consumption, as well as your emissions of pollutants and greenhouse gases.  Many require only modest changes to often long-ingrained driving habits.  Adopting the following fuel-efficiency tips will also make your driving safer and less stressful, as well as reduce vehicle wear and tear.

Don't drive aggressively

Some tests have found that aggressive driving habits – “jackrabbit” starts from stops, speeding, darting in and out of traffic and braking hard – can increase fuel consumption by as much as 37 per cent and increase some toxic emissions fivefold.  This astonishing fact is tied to physics: your vehicle uses the most energy during acceleration and loses much of that energy when forced to slow rapidly.  By simply retraining your right foot to go easy on the gas and brake, you can slash your fuel bill more than by any other change in driving habits.  When leaving a light or stop sign, pretend there’s a scalding cup of coffee on the dashboard, ready to be launched onto your lap if you hit the gas too hard.  Instead, accelerate slowly and steadily, shift into higher gears (if you have them) at relatively low rpms, and avoid “flooring it” when passing, except when safety demands it.  To eliminate hard braking, leave plenty of space between you and the vehicle ahead and anticipate changing lights, allowing you to coast to a stop and perhaps catching the light as it turns green.

Drive the speed limit

Depending on its aerodynamics, frontal area and weight, your vehicle is at its most fuel efficient somewhere between 65 and 90 kilometres per hour (kph).  Above 90 kph, wind resistance makes gas consumption a steadily losing game; i.e. the faster you go, the more fuel you consume.  As a rule of thumb, if you reduce your highway speed by 10 kph – say from 110 to 100 – you’ll cut your fuel consumption by 10 per cent.  Slow down from 120 to 100, and you’ll save 20 per cent or more.  Besides eliminating speeding tickets, sticking to the speed limit is also generally safer and more relaxing, especially on busy roads.  A European test revealed that aggressive driving, including speeding, only reduced travel time by about four per cent, or 2.5 minutes for every hour of driving.  On long trips, at slower speeds, you’ll easily make that time up by stopping less often for fill-ups.

Use cruise control

Especially on uncongested, divided highways, cruise control keeps your vehicle at a steady, efficient speed and generally avoids gas-guzzling surges.  One exception is on steep hills, particularly into strong headwinds, when it’s more fuel efficient to briefly get out of cruise and go a little slower up the hill, avoiding a hard acceleration, and regaining the lost speed on the downward side.  Incidentally, for gas misers, coasting downhill with the transmission in neutral or the clutch depressed actually uses more fuel than if you’re in gear, because it signals the engine to idle; it’s better to just take your foot off the accelerator.  On the flats, it’s best to get into an overdrive gear (if you have one) as soon as you can – it slows the vehicle’s engine speed and thus saves gas.

Should I consider buying a used vehicle?

Buying a used vehicle can make economic and environmental sense, as long as it’s only about five years old. Vehicles much older than that can emit considerably more air pollutants than newer models.

Air conditioning: myth or fact?

There’s been a long-standing debate about vehicle air conditioning (AC) and its effect on fuel consumption.  One camp says AC, because its compressor takes power from the engine, increases fuel consumption and should generally be avoided.  The other notes the alternative of opening windows on hot days increases aerodynamic drag, particularly at highway speeds, and thus reduces fuel consumption even more than if the AC was turned on.  But some recent tests, including one by Consumer Reports, indicate that with modern air conditioning and aerodynamics, it makes negligible difference to fuel consumption if you use the AC or open the windows.  The one place where it might still make sense to open the windows is at city speeds, where aerodynamic drag is less.

Try weight watching

Tests indicate every extra 45 kilograms of weight inside the vehicle can reduce fuel economy by up to two per cent.  So it’s worth shedding unnecessary weight, such as that sand bag sitting in your trunk year round.  A loaded roof rack, because of its aerodynamic drag, is even worse, reducing fuel efficiency by some five per cent.  So when you’re not using that rack regularly, remove it.

Keep your tires properly inflated

Tire rolling resistance is one of the main factors affecting fuel consumption and rolling resistance is most affected by tire inflation.  Each 10 per cent (typically 28 kPa or 4 psi) of under inflation translates into two per cent increased fuel consumption.  So a car with one tire running at 193 kPa, or 28 psi, rather than the recommended 220 kPa, or 32 psi, is underinflated by 12 per cent equating to 2.5 per cent increased fuel consumption.  Multiply that by four tires with likely the same inflation levels and you're at 10 per cent wasted fuel consumption.  The cost isn't just to our wallets either.  For each litre of additional fuel consumed, 2.4 kg of CO₂ is emitted to the atmosphere.

Idling gets you nowhere

When you’re idling, your vehicle is getting zero kilometres per litre.  Idling a typical 10 minutes a day can add up to 100 litres of fuel a year, plus produce considerably more pollutants than when you’re driving.  By simply turning off the ignition every time you’re stopped for more than 10 seconds, except in traffic, you can thus save $100 a year, at $1 per litre.

Even in winter, today’s computer-controlled, fuel-injected engines need no more than 30 seconds of idling. The best way to warm up a vehicle is to drive it.  A cold car does burn more fuel for the first couple of minutes – in fact, a short winter trip burns 50 per cent more fuel than the same trip in summer.  One solution, on chilly days, is to use a block heater, on a timer, for no more than two hours before setting out.  Another is to combine errands on winter days, so you’re not constantly starting a cold vehicle.

Keep your vehicle tuned up

A properly-tuned vehicle is more efficient and hence uses less fuel.  For example, dirty spark plugs increase misfiring, dirty engines oils increase friction and clogged air filters make the engine work harder, though the latter’s impact is not as great in modern engines as it once was.

Use the grade of motor oil recommended by your vehicle maker.  For example, using a 10W-30 oil instead of a recommended 5W-30 can reduce your mileage by one to two per cent.  Using synthetic oils or ones treated with friction-reducing additives can also improve fuel economy.

Monitor your mileage

The best way to measure the effectiveness of the above tips for your vehicle and the type of driving you do (i.e. city versus highway, winter versus summer, hills and winds) is to monitor your mileage, or kilometres per litre.  To do so, make a habit of setting your trip odometer to zero when you fill up, writing down the distance traveled and litres purchased when you next fill up and then dividing the former by the latter (km. traveled ÷ litres purchased = km. per litre).  If you’d like more precise, detailed information, use your vehicle’s onboard mileage computer (if it has one) or purchase an installable gauge.  Both can provide real-time feedback on how your driving habits are affecting your mileage.