8 Myths About Fuel Economy

It’s ironic that though we live in a time when information was never more plentiful that misinformation, fallacies and myths persist. In the case of cars, the automobile has been called the second-most expensive purchase many will make, and marketers also have something to gain or lose depending on what you may think about saving money on fuel. Here are 8 common myths about fuel economy:

  1. Letting a vehicle warm up is best for gas mileage- This holdover from the good old days persists, but modern cars are designed to drive within a few seconds of being started. Letting them sit and warm up may be convenient – like in the winter to defrost and warm the interior – but this does not save gas. A car gets 0 mpg as long as it is sitting. It is true an engine must reach an optimal operating temperature for best fuel economy, but manufacturers often recommend gently taking off, and letting the engine warm up as it’s carrying you down the road. It will warm faster if you do this while avoiding heavy loads until the engine temperature comes up.
  2. A vehicle’s fuel economy decreases with age- If your car is 4- or 7- or even 10-years old, is it starting to become less efficient? Should you therefore think about replacing it? Well, you may want to just to get a more-efficient newer car, but as for whether it has dropped from original spec, assuming it’s maintained, it should be OK. “Vehicles that are 10 or even 15 years old will experience little decrease in fuel economy if properly maintained,” says the EPA.
  3. The smaller the car, the better the fuel economy- This also used to be true before the advent of newer technologies, and the idea hangs on. The most efficient little non-hybrid car sold is the 40 mpg Mitsubishi Mirage. A Toyota Prius c hybrid actually is a chart topper at 50 mpg, but many bigger and more powerful cars are also competitively efficient. Fuel saving technologies besides hybridisation, including direct injection, turbocharging, low rolling resistant tires, and even – despite the VW scandal – diesel engines. About half of the 2016 model year cars on the EPA’s top-10 list are mid-sized or large cars or wagons, as a matter of fact. Most are hybrids.
  4. The Government tests fuel economy for all vehicles- Actually most passenger cars and light-duty trucks are subject to testing, but law rules out testing for vehicles with gross vehicle weight rating of over 8,500 pounds.This means no official fuel economy rating is required for trucks that can do duty for passengers like the Ford F250/350, Chevrolet/GMC 2500/3500, and Dodge 2500/3500 vehicles. These exceed this weight limit and are not tested.
  5. EPA window stickers are a form of guaranty on fuel economy- After hearing “your mileage may vary” enough times, hopefully most people do not think the fuel economy certification is a federal vouching for the stated number. In case you did not make this connection, the EPA writes its own qualification on the subject. “The primary purpose of EPA fuel economy estimates is to provide consumers with a uniform, unbiased way of comparing the relative efficiency of vehicles,” says the federal government. “Even though the EPA’s test procedures are designed to reflect real-world driving conditions, no single test can accurately model all driving styles and environments.” There are too many variables to account for including how people drive and even the type of gas put in the car. Ethanol at a 10 percent mix with regular gas can decrease fuel economy by around 3 percent, says the EPA.
  6. Manual transmissions get better fuel economy than automatics- Do you hear that? That’s the imaginary loud buzzer for Wrong Answer! It is no longer a given that manuals trump automatics for fuel economy. Advanced automatics may now net the same or better fuel economy than a vehicle of the same type equipped with a manual – though there are exceptions here as well. The type of transmission used in most hybrids and now being used to optimise conventional cars – CVTs (continuously variable transmissions) – also tend to do better. Drivers however have pushed back, and some enthusiasts have said they can’t stand CVTs or simply prefer the feel and control of a manual. Even the new dual-clutch automatics that may be manually shifted have experienced vocal detractors now that these have been on the market several years. And, a well-operated manual may still yield great results but the watchword is how well it is operated. Meanwhile automakers have largely moved away from offering manual stick shifters in types of cars that used to have the option.
  7. It takes more fuel to start a car than allowing it to idle- The advent of stop-start technology ought to be proof enough this is a myth. In case you did not get the memo however, idling may use a quart to a half-gallon of fuel per hour at a cost of 1-2 cents per minute. One should thus turn off the engine when sitting still, except when in traffic or waiting in line. New engines start very well and efficiently, especially when warmed.
  8. Premium petrol yields better economy than regular- “You will probably experience no benefit from using premium fuel over regular,” says the EPA to anyone whose engine is not specified to be premium-only, or in the case of engines that don’t otherwise knock on regular. Otherwise, if it runs on regular, use regular. The extra octane of premium and plus do not improve economy says the EPA, but they will cost more to fill up.