Eco Mode – Why Do Cars Have It And Should You Use It?

“Eco Mode” is a feature you’ll find on many newer cars. In particular, American and East Asian manufacturers often include a button specifically for the purpose of turning on Eco Mode.

It’s short for “Economic Mode” and represents the fact that you’ll be burning less fuel. That’s kinder to your wallet in both the short and long terms, thus “economic”. It’s also, as you can probably tell, better for the environment. (Or perhaps “less bad” would be a more accurate term.)

There are a couple of variants on the name, but we’ll get into them deeper into the article.

• What is Eco Mode?
• What does Eco Mode do?
• Eco Mode – on or off?
• Eco Mode disadvantages.
• How much money does Eco Mode save?
• Other engine modes.
• Eco light/indicator.

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What Is Eco Mode?

Eco Mode (also known by its other names – see further below) is an engine mode.

An engine mode, in turn, is an electronically-controlled way in which the engine’s normal running is adjusted. The ECU will change things such as the throttle’s responsiveness or the shift pattern of the transmission. More advanced versions, more commonly found on newer vehicles, will also work with the ignition timing and fuel quantities or the air:fuel ratio. A few will also work with the electrical system and air conditioning, reducing their load on the engine.

In Eco Mode, things are automatically adjusted for maximum fuel economy.

However, for example, in Sport Mode, the engine’s workings become more powerful.

Using Eco Mode is a good idea to keep your fuel costs as low as possible. I’ll go into how much you can expect to save later on.

What Does Eco Mode Do?

In the previous section, I mentioned a few common ways that engine modes adjust the way the engine functions. In Eco Mode, this leads to a better fuel economy.

All manufacturers build their engine modes differently. Because of this, no two are usually exactly the same and might affect different things.

• Throttle responsiveness – the throttle pedal (also known as the accelerator or gas pedal) controls how much air travels into the engine at any given moment. It’s a bit like bellows for a fire if it helps to think of it that way. The more air coming in, the more powerful the combustion reaction will be. In the olden days, a wire controlled the throttle plate – nowadays, it’s a position sensor (TPS). The ECU takes this information onboard, still, but slows the response down slightly. If the throttle opens slower, you won’t use as much fuel to accelerate the car.
• Transmission shift pattern – for maximum fuel economy, the transmission should be in the highest gear logistically available at any given moment. It should also change gear as infrequently as possible. Since there’s less going on here as well, the car might feel like it’s struggling more than usual with basic tasks. However, it will be saving fuel.
• Fuel quantities and air:fuel ratio – when you need to accelerate hard (for example), your air:fuel ratio becomes richer. That is, there is more fuel per unit of air than the optimum. This happens because richer mixtures tend to provide the engine with more power. However, it’s less efficient, not to mention worse for the environment. Turning Eco Mode on will keep the air:fuel ratio as low as possible, depending on your driving circumstances.
• Air conditioning and electrical systems – by essentially decreasing the effectiveness of the AC and less important electrical systems (such as the interior lights, heated windshield, radio, and stereo, etc.), the car will have less to power. As a result, the fuel it’s burning is more effectively converted into power and sent to the wheels.

There are many other things that different car makes will incorporate into their individual programs. For example, the new Honda Accord models use cylinder deactivation (VCM: Variable Cylinder Management).

All of these adjustments will, inevitably, lead to the car feeling more sluggish to drive. Everything will feel sort of lazy – not unresponsive, by any means, but less responsive than when your vehicle is in other engine modes. Such is the price of saving money on fuel.

What Are Some Other Names For Eco Mode?

Honda calls its Eco Mode setting “ECON“. It’s the same thing, essentially, just Honda’s name for it.

Some cars from Kia/Hyundai call the setting “Active ECO” – many still call it Eco Mode, though.

Other than that, “Eco Mode” is a reasonably unanimously used term across the automotive industry.

As this video from Kia shows, you activate it in different ways, depending on the vehicle. There is usually either a button directly for Eco Mode or for a wider selection of engine modes.

Eco Mode works very similarly to the overdrive system – the O/D button – especially if it works directly with the transmission. There are a few similarities as to how you should use the two. Check out an article on when to use overdrive here.

Should Eco Mode Be On Or Off?

In almost every situation, you can drive with Eco Mode on with no worries at all.

There are lots of people who suggest you should only use it here or there. In the majority of cases, that won’t be true. You can use Eco Mode pretty much all the time. There’s nothing wrong with having Eco Mode on. Your acceleration will be diminished, but it’ll be far from nonexistent. There will be no need to turn it off to accelerate hard in most situations. For example, you shouldn’t have any issue speeding up to merge onto a highway (unless the on-ramp is particularly short).

No matter whether you’re driving in the city or on the highway, you’ll be saving gas – to some extent, at least. It’s likely to have a more significant impact on your motor when you’re driving in the city with it on, but you’ll see results wherever.

It would be best if you turned Eco Mode off in a few select situations.

• Whenever you need the car to be more responsive – for example, if you need to accelerate hard or you’re driving along a road where you need a high level of car control. Doing this will mean you have greater control of the car and, therefore, that you’re safer. A few cents of gas is more than worth the cost here.
• When you’re towing – the jury’s still somewhat out on this one, but there are a good many reports of transmissions having been ruined by engine modes and overdrives if they’re used while you’re towing something. You should turn it off, so your car is at the very the least responsive. It might also save damage to your transmission, depending on how advanced the Eco Mode system is.

Are There Any Disadvantages To Having Eco Mode On?

Unfortunately, there are always disadvantages. Here, though, they aren’t anything more than what you might expect.

With vehicles – and, in fact, a lot of things – it’s well known that the slower you go, the fewer resources you’ll use to get there. The vice versa is also true: the faster you want to go, the more resources you’ll use. It’s all related to terminal velocity and resistance and thermal properties of materials… not things worth getting into just now.

If you want to drive more economically – thus engaging Eco Mode – you’ll need to drive slower and smoother. Smooth driving is good all-round – whether you want to go faster or slower – and well worth learning how to do correctly.

All Eco Mode does is, at its base level, force you to drive more like this. The car can’t speed up as quickly, and so you have to drive slower. It doesn’t use as much power for other things, even though you might try to force it.

In essence, it’s no different from having a light right foot and turning all your other devices off.

The downside?

• You’ll be driving slower than you might like.
• The car won’t be as responsive as it usually feels.
• If the AC or electricals are affected, it might make you want to turn Eco Mode off.

These aren’t so much the symptoms of Eco Mode as the symptoms of driving economically. If saving as much fuel as you can is what you need, you should be driving like this – with or without Eco Mode.

How Much Money Does Eco Mode Save?

First of all, disclaimer: there’s no real way to tell you this. We all drive differently. How we drive is actually what makes the most difference, rather than whether Eco Mode is turned on.

Most manufacturers estimate that you’ll save approximately 5% on gas costs when using Eco Mode. The average American spends $3,000 per year on gas representing an annual saving of $150. That’s not too bad.

For the most accurate reading possible, I decided to run my own test.

My Basic Test – Eco Mode Vs Normal Mode

First of all, this wasn’t a test confirmed in scientific laboratory-style conditions – as much as I wish I had the resources to do that. (Anyone got a spare test track?) Therefore, the results aren’t necessarily 100% accurate and would likely be different if replicated.

Nevertheless, my findings were interesting.

The VW Golf TSI Bluemotion has an Eco Mode that increases fuel economy “by optimising your engine and gearbox performance to save fuel”. It also reduces the power draw of the air conditioning system.

In my experiment, another person and I took the Golf 10 miles down the road and then 10 miles back again, from Lichfield to Sutton Coldfield down the A38. This route involves a good mix of fast, (usually) open roads and more congested city driving.

Although you can get your hands on OBD plugins that monitor your car’s status and produce all sorts of weird and wonderful graphs, I don’t currently have one. As such, I only had the car’s onboard “average trip mpg” calculator to use.

The plan was to drive to Sutton to see what the average mpg was for that trip. We would do that in Normal Mode. Then, on the return journey, we’d put the car into Eco Mode and see what happened to its average mpg. If the average mpg went up, it would indicate that the journey was more economical in Eco Mode than Normal Mode. And, of course, the vice versa would also be true.

Unfortunately, things didn’t quite go smoothly, and the last 2 miles of the return journey were held up in a traffic jam which added about half an hour onto the journey time. The Golf, however, is fitted with a stop/start system, so we (unintentionally but unavoidably) incorporated that into the experiment.

Here are the results.

The outward journey yielded an average of 41.8 mpg – in Normal Mode.

When returning, we pulled up with the car reading 44.1 mpg. That was in Eco Mode with the stop/start system on for the traffic jam.

Despite the jam, you can see that there was an increase in fuel economy. In percentage terms, Eco Mode led to 5.5% less fuel being burnt.

I was surprised by how close this number is to the 5% expected value from many manufacturers, but there you go.

As noted, those results aren’t an accurate, repeatable, etc. scientific experiment. It was also affected by other unavoidable factors, such as the jam and potential minor differences in driving style between the trips. However, it was interesting to go through.

When Was Eco Mode First Introduced?

The history of Eco Mode involves the history of all engine modes.

Some trace the development of engine modes back to overdrive. Overdrive systems were originally bolt-on extras to the transmission in a rear-wheel-drive car and were first seen in the 1930s and 1940s. The purpose was to reduce the amount of fuel used at high speeds (on highways) by “over gearing” the gearbox (transmission) – that is, for the transmission output speed to be faster than the input speed. Over time, this system developed from an aftermarket extra into an electronically-controlled gear system.

Many would alternatively argue that the first engines with alterable “modes” could be found on early Land Rovers, first debuted in 1948. The second gear stick allowed drivers to shift the four-wheel-drive settings. This, in essence, altered the “mode” of the engine, meaning the driver could use it for different things in different situations.

It’s hard to know, really, because each manufacturer went their own sort of way and then met up again in today’s age. Many things could have inspired – partially or fully – engine modes. Undoubtedly, the greatest of these is the ever-increasing amount of electrical components within a car and the dependence on ECUs and sensors.

Over time, engine modes have become commonplace on many cars – especially in the last decade.

As well as Eco Mode, you will also likely find several other types of engine mode.

Sport Mode

Sport Mode is usually the opposite of Eco Mode in terms of engine performance.

Everything gets sharpened up. The throttle response becomes even more sensitive, and the air:fuel ratio might become richer. You’ll move faster, yes, but you’ll be using more gas as a result.

My opinion on the whole matter – perhaps controversial, perhaps not – is that Sport Mode is actually the safest engine mode to drive with. That’s because everything is as responsive and as precise as is possible. The car will react quicker to your input, and in emergency situations, those moments could be vital. However, yes, you’ll be using more fuel. And if you choose to put it in Sport Mode and absolutely rag it… well, it’s not safe anymore!

It may also affect the suspension, tightening it up and sometimes making it unbearably juddery. If the engine mode affects the suspension, I usually wouldn’t put it in Sport Mode. Unless you’re on a track, stiffer suspension is unlikely to make any difference to your car’s performance whatsoever. And it’s just awfully uncomfortable. For long journeys, it would be a nightmare and cost you more in chiropractor visits than you’d ever save in fuel.

Comfort Mode

“Comfort” Mode might otherwise just be called “normal”.

It’s what most manufacturers build their cars to be – day-to-day runners. If you’re just using your vehicle for everyday things like an average person – shopping, dropping the kids off at school, or visiting friends, comfort is probably your primary concern.

This mode is something in the middle between Eco Mode and Sport Mode. The suspension is generally relaxed (if altered at all), and everything is focused on the balance between everything. Decent performance and decent fuel economy, but the main aim is comfort. Creating a place you like to sit in.

Snow/Ice/Winter Mode

This engine mode is designed explicitly for slippy roads. It’ll force the car to drive in such a way as to minimize the risk of sliding.

Usually, Snow Mode will make the following adjustments:

1. Throttle responsiveness is lowered in a similar way to Eco Mode. The slower the wheel’s speed changes, the less likely you are to lose traction.
2. On the subject of traction, traction control is generally tightened up and put into a hyper-alert setting. Your grip is, therefore, maximized.
3. Automatic transmissions select the highest possible gear so that everything is nice, gentle, and slow.
4. Brakes become gentler, meaning you’re less likely to lock the wheels up. In snow or ice, it’s imperative to keep the wheels turning – otherwise, you’ll have a very low coefficient of friction with the road, meaning stopping turns from a delicate squeeze into a panicked stamping affair with little in terms of results.

All of these combine to give you the best traction possible – vital in slippy conditions. You might also need to use this mode in heavy rain or where aquaplaning is a possibility.

Individual Mode

Most cars now feature this mode. It allows drivers to select and customize the settings they want.

It’s helpful, to some extent. However, manufacturers put limits on exactly what you can do for safety reasons.

Is The Eco Light On The Dashboard A Different Thing?

When you turn Eco Mode on, a light will illuminate somewhere to let you know what’s going on.

However, many cars also have an “Eco” light on the dashboard, often looking something like this.

This particular light is unrelated to Eco Mode. It’s not a warning light, either.

When you see the Eco light appearing on the dashboard, it’s simply showing you that the car is driving pretty close to its maximum mpg. As such, you’re most likely to notice it when you’re traveling along empty, flat country roads at a constant, relatively low speed. In these situations, your engine is doing the minimum amount of work.

The light doesn’t represent an engine mode. It’s simply an indication that you’re driving economically – an invitation, if you will, to pat yourself on the back and give yourself a gold star. Other than that? There’s not really anything going on.

It’s not a warning light, and there’s nothing to worry about. It’s just there – quite literally – to say “well done.”

For more information on the Eco light, consult your owner’s manual.

How Else Are Cars More Economically-Friendly?

In recent years, cars have become much more friendly to your wallet.

Here are just a few of the innovations that have led to more efficient dollar spending.

• Fuel injectors rather than carburetors.
• Exhaust Gas Recirculation (EGR).
• Improved tire patterns and treads.
• Hybrid systems – for example, kinetic energy recovery.
• Improved air conditioning systems.
• Advanced ECUs and computer programming.
• Specially designed body shapes to improve airflow and reduce drag coefficients.
• Smaller, forced induction (turbocharged/supercharged) engines.
• Diesel engines rather than gasoline (although, by the current trend, electric cars are soon to make diesel advances redundant).
• Weight-saving materials (aluminum, carbon fiber, etc.) and building techniques.

Conclusion

Overall, Eco Mode is a beneficial little gadget to have. It forces you to slow down and thus save money on gas.

For the best results, though, in my opinion, nothing can really beat learning to drive more economically yourself. Eco Mode – and programs like it – will certainly assist you and perhaps lead to even further savings, but there’s little Eco Mode does that you couldn’t do yourself.

• It reduces the throttle response – you could be more gentle with your foot instead. Doing this would also consequently affect the air:fuel ratio and amount of fuel used.
• Eco Mode reduces the power going to the AC and other electricals – turn them off.
• Driving gently and smoothly greatly improves fuel economy.

There are some things you can’t change. For example, the shift patterns in an automatic transmission or the ECU-controlled air:fuel ratio. That’s where Eco Mode is beneficial, covering the things that we can’t.

It would be best if you drove with Eco Mode on as much as you can to save money on gas.

Thanks for reading!

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