How To Improve The Fuel Economy Of A Diesel Engine

Whether you are trying to save a penny or save the earth, fuel economy has been a healthy topic of discussion for decades. Diesel engines are notoriously known for their big gas guzzling capabilities so throughout this post, I have gone through some of the useful ways in which all of us can go about saving a few more drops and be a little bit more economic with our fuel usage as well as some helpful information about fuel economy in general.

There are ways that owners of vehicles with diesel engines can be more fuel economic in short, Some of the biggest things you can do to improve fuel economy are change the way you drive. Things like making sure not to suddenly accelerate or brake, trying to change gears under 2000 RPM and make sure to keep your diesel engine regularly serviced will help to keep those fuel bills down.

Obviously above is only some of the ways you can improve your Diesel fuel economy, keep reading to see some other tips and tricks.

What is Fuel Economy

A little bit of background.

To start things off I am sure that most of the readers of this will not need much of an explanation on what fuel economy is but for those of you that need a crash course read along carefully. Broadly put fuel economy is how far your fuel gets you and better fuel economy would be getting more distance from the same amount of fuel.

Car manufacturers have been working on making improvements to fuel economy from as early as 1910 and the many countries even have strict regulations and requirements for what new vehicles being imported must be able to achieve with regards to fuel economy.

When it comes to diesel engines we actually have an example of an engine that is more fuel efficient than a traditional gasoline engine. Obviously, that does not mean those of us paying the premium for the ticking of a diesel engine under the hood should be any less concerned with how to get even more out of the thing!


Ways to help Improve Fuel Economy.

Tire Pressure.

The pressure in your tires is responsible for just how much of the tread will be touching the road. If you have a low tire pressure you will have an increased amount of rubber holding you back as you drive which means the engine has to work harder for every bit of distance it covers. Making sure that you check and maintain that optimal tire pressure regularly (which you can find in the operators manual) will really help to hold back the drops in your tank from being used unnecessarily.

Tyre Pressures can make a dig difference to your fuel economy


Tires make a difference.

Big heavy tires with aggressive treads found often on 4x4s and SUVs will cause a huge amount of lost fuel economy as we mentioned already, with great traction comes less fuel economy (I don’t think that’s what they told Superman.) Surprisingly to me, new tires actually can cost you up to 7% on fuel efficiency. That does not mean you should be avoiding replacing those old torn up ones you still have but be aware that they will make a difference. According to the research, this is most impactful at speeds below 80 kilometers per hour.

Keep it light.

A great deal of vehicles with diesel engines are generally going to be working hard in their lifetime but even this tip is relevant even for the odd saloon diesel too. Make sure that you are not carrying unnecessary weight with your vehicle. Ever kilogram extra is costing you in fuel economy.

Other forms of vehicle maintenance.

Sadly, your vehicle can not get up and go have a shower all on its own and it is up to us to make sure we keep everything under the hood in the as best condition we can. Make sure that you keep your engine running at optimum efficiency by regularly doing maintenance such as having the oil changed regularly, ensuring that the spark plugs are clean and the air filter is replaced when it gets dirty as well as the timing of the engine should be checked to ensure that the engine is giving you your most fuel economic experience.


Now most of us do not have the supercar shapes of a Lamborghini, designed with a wind tunnel and the body of Marylin Monroe in mind, and with that said it might not be a surprise that drag can have a big effect on your fuel economy. One of the most effective ways you as a driver can reduce this is by making sure that the windows of the vehicle are only slightly open when driving above 60 kilometers per hour. This will reduce drag and shave a little off the top of your bill.

Air Conditioning.

While we are on the topic of cooling and airflow it would be a sin not to mention the dreaded drain of the air conditioner. Now I know like myself many of us just cannot help themselves on those blistering hot days but keeping the fans on cold without using the air conditioner will mean the engine will use be using less power which means more savings.


Driver Responsibilities

Cut it out.

Keeping the engine running when you do not need to is a key way to waste fuel. Of course, there are times when you may not find it worth switch off as the kids run back into the house to grab their lunch but as a whole try to keep this principle in mind as every second that engine is on and going nowhere it is burning away your money.


Some of us have a rather heavy foot when it comes near an accelerator but you might be using it to kick yourself when you find out that it is only costing you in fuel efficiency when you go looking for the floor of your vehicle. Sudden acceleration and breaking will use far more fuel than a smoother more calculated drive. It may not be as fun but you should consider the amount of wasted fuel in making the engine work twice as hard to reach a speed you would be reaching a few moments later in any case if you just took your time. It is not only about how fast you like to push down the accelerator but also the overall speed you want to be traveling as well Generally anything over 80 kilometers per hour will cause you to start losing fuel efficiency, and fast. The faster you go the harder the engine will have to work to keep up at that speed meaning that your fuel usage just continues to grow.


Making sure to use slower more steady gear changes will definitely help you to save on your bill. Moving from gear to gear more slowly will avoid unnecessary revving and keep you from need refills as often. Try to not over rev the vehicle too much before changing gears as well. Keep in mind that in a diesel car you should try and change up before reaching 2000 RPM changing up. A side, however, some engines struggle at low revs too and this should be kept in consideration in order to try and maintain an optimal operating area for your rev counter.


It is very important to try and find your engines sweet spot when you are going to be maintaining a speed for some time because this can stop a lot of unnecessary fuel wastage while moving at cruising speeds. Cruise control is also a good way to help with this if your vehicle is equipped with it as it can help avoid unnecessary acceleration up hills.

Think ahead.

Take the time to focus on the road and anticipate upcoming traffic lights when you can. Slowing down gradually to not come to a full stop when as the lights change will help to save you a significant amount in the long run. In a different light, you should also be trying to keep an eye on the rise and fall of the land. Using gravity and momentum of downhills to help carry you up the hill ahead will make a big difference that the engine does not have to compensate for.


Related Questions

Should I Use Biodiesel In My Diesel Engine?

While biodiesel is very well known as the green alternative to using traditional diesel in your engine it is important to note a few things. The idea of lowering your carbon footprint is not a myth here and with the decreased emissions it really is a great alternative to diesel if you are focusing on environmental impact alone. As this is mainly about fuel economy however it is important to mention that with the usage of biodiesel you will see up to a 10% loss in both performance and fuel economy.

Should I Use an Additive like Engine Cleaner In My Deisel Engine?

Simply put, im not sure. Other than feeling like I am being sold snake oil some of the time I have never had actual experience with any additives for an engine that is designed to increase performance or fuel economy. With that being said, there are mostly very positive reports regarding additives and seldom do I hear anything but good responses to the use of them.

I hope that for some of you there will be a few helpful tips to take away and become more efficient drivers and vehicle owners. We can all be a little bit sleepy sometimes when it comes to our maintenance but hopefully with the information provided you will find it somewhat easier to save a bit on your fuel bill.

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