Let’s face it, nobody likes paying for gas (or petrol, or whatever you call fuel in your neck of the woods).
With fuel prices skyrocketing in recent years, more and more drivers are turning attention to ways to reduce their fuel consumption and minimise pain at the pump.
And why not? You’d be crazy not to try and reduce your fuel bill, after all.
Many modern cars come equipped with an ‘Eco mode’ or ‘Eco drive’ option, which is designed to reduce fuel consumption and CO2 emissions.
However, this technology is present in various forms on older cars as well (such as my fifth generation Subaru Legacy – I’ll use this as an example later in the article) and so I thought it might be relevant to the readers of this site to discuss whether you can use Eco mode all of the time, and the pros and cons of using it frequently.
While using Eco mode may seem like a no-brainer, as it can save you money on gas and reduce your carbon footprint, there are some benefits and drawbacks to consider before you decide to drive in Eco mode all the time.
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Can You Safely Drive In Eco Mode All The Time?
If you’re after a quick answer, then that answer is ‘yes’.
It is perfectly safe to drive your car in eco mode all day, every day and it won’t cause any damage to your engine or transmission (provided you are keeping up-to-date with routine maintenance and servicing – not adequately servicing your car within the manufacturer’s recommended intervals is what really tends to kill a car’s longevity and reliability).
So if you like the fuel savings that eco mode brings, or you prefer the way your car drives when eco is selected, feel free to keep doing that to your heart’s content.
However, if you’d like a more comprehensive explanation of eco mode, its pros and cons, and the safety of using it all the time, then keep reading:
What Does Eco Mode Actually Do In Your Car?
Firstly, let’s take a closer look at what Eco mode actually does. When you activate Eco mode, your car’s engine and transmission are adjusted to deliver maximum efficiency.
This means that your car will accelerate more slowly, and the transmission may shift earlier into a higher gear to keep the engine revs low.
The air conditioning system may also be adjusted to reduce its power consumption, and the throttle response may be dulled to discourage hard acceleration. In fact, the dulled throttle response is often what you will notice the most.
Long story short, when eco mode is activated the electronic brain in your car adjusts the manner in which the car responds to throttle input to focus on running as efficiently as possible.
Benefits Of Eco Mode
One of the main benefits of Eco mode is that it can help you save fuel. In fact, this is the primary benefit and the main reason drivers use eco mode.
Because eco mode effectively configures the throttle response, engine and transmission of your car to prioritise efficiency over responsiveness and power, you’ll generally reduce fuel consumption provided that you don’t then compensate for muted performance by driving more “aggressively”.
What is critical to understand is that eco mode isn’t some magical thing that bends the rules of science and physics allowing you to enjoy the exact same level of responsiveness and power from your car while also saving fuel (because if that were possible, the manufacturer would have just built the car like that from the outset).
All eco mode does is sets the car up in such a way that it encourages more economical, frugal and gentle driving. In other words, you are instructing the car to sacrifice some of its performance in the name of economy. Eco mode is really an “encouragement tool” that nudges you – the driver – in the right direction. With judicious driving you could almost certainly enjoy the same MPG/economy driving in normal, or even sport mode, as you can with eco mode … it’s just that eco mode makes it easier to drive in an economical fashion.
In addition to saving you money, using Eco mode can also be good for the environment. When your car uses less fuel, it produces fewer CO2 emissions. This can help to reduce your carbon footprint and contribute to efforts to combat climate change.
How Much Fuel Does Eco Mode Save?
The answer to this question depends greatly on:
- What sort of car your drive – Not all eco modes are created equal (and for some cars I’ve owned in the past, I swear it’s just a placebo button)
- How you drive your car – e.g. if you engage eco mode do you wind up driving harder to compensate for the reduced responsiveness?
- Where are you driving – Eco mode tends to be less effective around town or in the city because drivers are more likely to compensate for reduced responsiveness and power when pulling away from the lights, merging across lanes etc. However, when cruising on the motorway or open road, using eco mode to keep engine RPM low helps to save fuel.
Realistically, the difference in terms of fuel consumption is likely to be in the range of a few MPG. Eco mode won’t make your Audi RS6 a Toyota Prius in terms of fuel consumption, but the saving also isn’t to be sneezed at.
Drawbacks Of Eco Mode
There are some drawbacks to consider before you decide to drive in Eco mode all the time. Firstly, using Eco mode can reduce your car’s performance.
When you accelerate more slowly and shift gears earlier, your car may feel less responsive and less powerful. This can make it harder to overtake other cars on the highway or merge onto a busy road.
Our “family wagon”, a fifth generation Legacy, is a good example of this.
It has Subaru’s SI-Drive system that lets you select between three driving modes:
- I – This is the equivalent of eco mode
- S – Sport, but apparently (according to Subaru) this is the ‘standard’ mode you should drive in most of the time
- S# – Sport Sharp, which noticeably increases throttle response and adjusts the CVT transmission gearing for acceleration
Switching to I/eco mode it is very noticeable just how much less responsive and more “sluggish” the car feels. It is smooth, but you really have to mash the accelerator to make decent progress. That being said, for daily driving it is tolerable and definitely results in reduced fuel consumption (it would be hard to put an exact figure on it – I’d say maybe around 5%).
In addition, driving in Eco mode can be less enjoyable. For some people, the thrill of driving comes from the sensation of acceleration and the sound of a powerful engine. When you activate Eco mode, you may lose some of that excitement, as your car will feel slower and if you have a car with an active exhaust you’ll probably find that the sound output is deadened. The Legacy isn’t the most thrilling car to drive at the best of times, but there is a substantial difference in enjoyment when using S# vs I.
Another potential drawback of using Eco mode is that it can be less safe, at least when you need to call on your car to accelerate quickly.
When you drive in Eco mode, your car may take longer to accelerate, which can be a problem if you need to quickly avoid an obstacle or merge onto a busy highway.
Additionally, the dulled throttle response may make it harder to control your car in certain situations, such as when driving on a slippery surface or when making a sudden manoeuvre. When driving the Legacy I always put it in S# mode if I need to rapidly pull out of an intersection or pass on the highway. If the Legacy is in I mode and I try to pull away quickly, it feels like trying to launch a manual car in second gear as opposed to first.
Is Leaving Your Car In Eco Mode Bad?
So, is it bad for your car to drive in Eco mode all the time? The answer is that it depends on your driving habits and priorities.
If you prioritize fuel efficiency and reducing your carbon footprint, then driving in Eco mode can be a good choice. It’s not going to damage your car to exclusively use eco mode, that’s for sure (provided you are properly maintaining and servicing your car). You’ll most likely enjoy a modest saving in terms of fuel consumption, so long as you drive in the more sedate manner that eco mode encourages.
However, if you value performance and responsiveness, or if you frequently drive in situations where quick acceleration is necessary, then Eco mode may not be the best option for you. If you hate the idea of eco mode, you’re probably not missing out on a massive fuel saving anyway.
If you found this article interesting, you might also want to read about whether it is safe to drive all the time in sport mode.
