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Clean Transport

Published on December 30th, 2020 | by Barry A.F.

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A Guide To Fuel Efficient Driving — Part One

December 30th, 2020 by  


While electric vehicles (EVs) are very slowly taking over the world, most people still drive gasoline and diesel powered vehicles, known as internal combustion engine (ICE) vehicles. While we cannot bring them to carbon neutrality via greater efficiency, we can reduce their carbon footprint with how we drive.

For most people, they purchase a vehicle and go to the fuelling station when the needle is low. However, how one drives can get them many extra kilometres (or miles) from the same fuel, reducing the total amount of fuel consumed and the carbon pollution created (which also incidentally saves money).

This journey starts at the vehicle purchase. No matter how well you follow the steps below, a Hummer cannot match the fuel efficiency of a Geo Metro. But even the Hummer can achieve great gains in efficiency.

If you are looking at purchasing a vehicle, look up your local government’s mileage ratings and choose the most fuel efficient vehicle you can get away with. Buy only as much vehicle as you need, not as much as you want. Very few people need an SUV — it may be more convenient but it requires more fuel and will cost much more to own over its lifetime (more expensive tires, brakes, repair parts, insurance, etc.). Many people can get by fine with a compact or midsize vehicle even if they don’t want to admit it. Of course, check to see if an EV will fit the bill and is cost competitive.

Newer vehicles of the same class often have better efficiency than older vehicles, partly due to age/wear but also because technology has advanced. While we have not yet found a way to defeat the laws of thermodynamics, conservation of energy, and so forth, manufacturers have improved engines with technologies such as variable valve timing, direct injection, idle engine stop, more complex and more speed transmissions/continuously variable transmissions, and more. That said, if you are looking for a new vehicle, definitely consider an EV and remember that it may cost more up front, but, depending on your annual mileage and how long you keep the vehicle, it will often more than pay the difference compared to a gasoline vehicle in fuel savings.

All that said, you likely already have a vehicle and are not currently in the market for a replacement. So, on to the meat of this article: driving for fuel efficiency.


You may have heard of the term hypermiler. People who follow this philosophy seek to maximize their gas mileage and can use extreme and sometimes even unsafe methods to use less fuel. Do not do anything unsafe, even if it seems like it’s not a big deal.

To start with, you want your vehicle to be in tip top shape. In the old days of breaker points and carburetors, you had to get frequent tuneups, which entailed manual adjustments to make sure the air fuel mixture and spark/valve timing was as perfect as mechanically possible. With modern fuel injection and computerized timing and engine controls, you don’t need to do as much manually or as frequent maintenance. However, what you do need to do is even more critical. Make sure the spark plugs are within their rated lifetime and gapped correctly. Make sure the fuel injectors are clean, as fuel-injected vehicles need cleaner fuel than carbureted cars. Hence, you should aim to buy your fuel from companies that advertise the cleanliness additives in their fuel, which will also help maximize vehicle mileage (and consider using Top Tier fuel in countries that offer it, which has additional engine cleanliness detergents). Use the grade of engine oil recommended by the manufacturer. Thinner oil can improve economy a bit but may reduce engine life, so is typically not worth it.

Make sure your tires are at the air pressure recommended on the label inside the driver door. You can use a higher pressure for slight additional fuel savings (up to the maximum on the tire sidewall), but you will have to endure a harsher ride, which is not good for your suspension. Tire pressure will drop a few psi in winter and rise a few psi in summer. Check your tires monthly if you don’t have a tire pressure monitor built in. If you do, check its warning threshold — some will wait until a tire is very low before presenting a warning. Nitrogen in the tires has some benefits, but is not required. It holds pressure longer, so if you don’t check it frequently, it saves some work. Also, if you don’t drive a lot of kilometres per year, it slows down the aging of the tires somewhat — you may go a bit longer before the tires dry out from age. If your tires tend to die from tread wear, then the longevity advantage evaporates.

Of course you want to stay on top of fluid and belt replacement intervals so that components don’t wear out prematurely and cause a large repair bill. This does not help efficiency much but does improve vehicle reliability and expected lifespan. Your owner’s manual should have this information. Don’t skimp on preventative maintenance — for example, a timing belt that breaks on an interference engine or worn out automatic transmission fluid destroying the transmission are very expensive yet preventable. Skipped maintenance is false economy.

Keeping your vehicle exterior clean (especially in winter) maximizes its aerodynamics. Waxing may also help a few percent. And there are some rims that can improve aerodynamics slightly. Avoid aftermarket exterior accoutrements that change the exterior shape of the vehicle or add to it. Everything from grille guards to spoilers affect aerodynamics, and despite the claims, usually not in a positive way.

Tires also affect mileage somewhat, and you can buy fuel-saving ones. Some have less grip than standard tires, yet counterintuitively not all fuel-saving tires have less grip. Google can often help find the rolling resistance of any tires you are considering as replacements or fuel-saving tires in your vehicle’s size.

Higher octane fuel improves mileage in high compression engines. However, this is mostly in performance cars. There are some higher compression non-performance vehicles that gain a slight improvement from it, but nowhere near enough to justify its higher cost. However, many manufactures add extra cleanliness additives to their higher octane fuels and advertise this, trying to muddy the waters and get more people to buy fuel their car does not really need. Save your money and use the octane of fuel specified in the owner’s manual.

Stay tuned for Part Two — Driving Behaviours.


The standard disclaimers apply. All advice is for informational purposes only — CleanTechnica is not responsible for any damages caused by inaccurate information, and the user assumes all risks of following any advice provided. 
 


 


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About the Author

I've had an interest in renewable energy and EVs since the days of deep cycle lead acid conversions and repurposed drive motors (and $10/watt solar panels). How things have changed. Also I have an interest in systems thinking (or first principles as some call it), digging into how things work from the ground up. Did you know that 97% of all Wikipedia articles link to Philosophy? A very small percentage link to Pragmatism.   A link to all my articles



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