Driving a car is an energy-intensive activity. With gas prices fluctuating wildly in recent years and concerns over environmental impacts growing, more drivers are looking for ways to squeeze every last mile out of a gallon of gas. Many modern cars now come equipped with an “eco mode” – but what does this setting actually do, and should you be using it?
Eco mode is a driving setting that aims to improve fuel efficiency by modifying engine and transmission performance. The effectiveness of eco mode varies significantly depending on driving style and conditions. It can provide modest gas savings on highways, but may reduce performance or be essentially ineffective around towns.
In this comprehensive guide we’ll cover what exactly eco mode is, how well it works to save gas, when you should use it, potential downsides, what vehicles have this feature, tips for maximizing efficiency while driving in eco mode, and what types of drivers benefit most from activating this fuel-saving setting. Read on to optimize your car’s MPG…
Table of Contents
What Does Eco Mode Do in a Car?
So what’s happening when you press that little “eco mode” button? Essentially, eco mode changes multiple aspects of vehicle performance in order to improve fuel economy. This includes:
- Lower throttle response – Pushing the gas pedal engages power from the engine less aggressively, dulling acceleration
- Earlier transmission shift points – The vehicle changes gears at lower rpm points to stay in higher gears
- Altered climate control – The AC and ventilation may be adjusted to use less power
- Relaxed cruise control – Cruise engages at slightly reduced speeds
The overall goal is to have the engine work less hard to move the car, thereby consuming fuel at a slower rate. Eco mode aims to modify both the engine and transmission operation points to maximize miles per gallon (MPG).
In a Toyota for example, activating eco mode essentially instructs the engine computer to consume fuel in a more efficient manner. It is focused on smoothing out starts and stops, keeping rpms low, and optimizing the engine combustion procedures.
MPVs and SUVs typically see the biggest impact from eco mode. Their size and power demands otherwise result in lower efficiency. Turning on eco mode reins in all that torque in favor of gas mileage. Smaller sedans generally run efficiently already, so improvements are modest at best.
Now you know what eco mode is aiming to do, but…
How Effective Is Eco Mode at Saving Fuel?
This is the key question – does eco mode actually make that much of a difference?
Across the industry, eco mode results in fuel economy improvements generally ranging from 5-15%. In ideal highway conditions, some drivers may see up to 25% gains.
However, the impact diminishes significantly in stop-and-go traffic, cold weather operation, while towing, and with aggressive driving styles.
In a Ford test, strict use of eco mode resulted in a reported “real-world” mileage gain of 24 mpg vs 19 mpg, a 26% jump. However their simulated route was 55 mph steady highway cruising, representing close to the maximum possible performance.
In contrast, Consumer Reports tested a Hyundai Sonata under variable conditions both with and without eco mode enabled. They registered an average efficiency improvement of only 4 mpg overall, or just a 6% benefit.
So why this disparity in potential fuel savings? There appear to be several key factors:
- Driving conditions – The engine modifications are clearly optimized for steady state speeds around 30-60 mph. Inconsistent momentum works against efficiency improvements from cylinder and transmission changes.
- Driving style – An aggressive driver who frequently brakes hard negates the eco mode benefits compared to someone with an easy, steady acceleration profile.
- Vehicle size & type – Bulkier crossovers and trucks see a wider eco mode influence over their substantial power drain, while smaller cars already operate very efficiently in baseline mode.
If you are curious just how substantial the eco mode effect is in your particular vehicle, conduct an empirical test! Fill up the tank and reset your trip meter. Drive for at least 50-100 miles in standard mode, recording the odometer at each fill up. Then repeat the process exclusively in eco mode, trying to replicate the same routes. Compare the before and after MPG – the difference is your real-world benefit.
Now that effectiveness is quantified, when should you actually use eco mode?
When Should You Use Eco Mode?
Given its primary impact comes from mellowing out acceleration and keeping revs low, the ideal conditions to employ eco mode are steady, long drives at moderate speeds. The highway fuel mileage improvement can be worthwhile over the course of a road trip. The engine and transmission can hum along comfortably in top gear.
Conversely, eco mode shows few tangible benefits in stop-and-go traffic around town. The transmission is constantly downshifting and you may need sudden acceleration to make turns across traffic or merge safely. Eco mode could actually cost you MPG if driving style and conditions don’t align with its engineering focus.
We can make some general recommendations on when activating eco mode makes sense:
- Open highway cruising with cruise control on
- Low congestion suburban side streets
- Steady speeds between 30-60 mph
- Flat terrain without steep grades
- Warmer weather above 40°F
- Little need for sudden acceleration
However, there are also some distinct downsides of using eco mode to consider before pressing that button…
Are There Downsides to Using Eco Mode?
Eco mode aims to save fuel, not thrill you with performance. By dulling throttle response and keeping the engine out of its power band it can have some detrimental ride impacts:
- Acceleration lag – That Prius in eco mode is not going to snap your head back when the light turns green
- Power deficiency – Trying to pass on a two-lane road takes careful planning
- Shift behavior – The transmission may seem to “hunt” or suddenly downshift
Additionally, while climate settings are optimized for efficiency, not comfort. Some drivers in hot weather report the AC simply can’t keep up. This frustration over sluggish acceleration or an overheated cab may outweigh any small gas savings.
Eco mode also requires a light touch to operate safely. You simply won’t have the same snappy power if trying to accelerate around an obstacle or merge into traffic. Drivers need to be alert to potential safety limitations.
And while manufacturers state eco mode does not cause undue wear or damage, you still don’t want the transmission constantly hunting for gears or the engine straining under sudden throttle stabs. We advise the following precautions with eco mode:
- Avoid frequent starts and stops
- Allow plenty of room for safe acceleration and stopping
- Use sparingly if towing or under heavy loads
- Monitor the engine temperature
- Shift back to normal mode if conditions require full power
Now that we’ve covered the caveats, what vehicles actually have this feature and how do you switch it on?
What Cars Have Eco Mode and How Do You Activate It?
Eco mode takes software programming so you’ll only find it in later model vehicles – generally 2010 model year or newer. As fuel efficiency continues growing in importance, more manufacturers are including eco mode across their fleets:
Toyota – Prius, Camry, RAV4 and many models have a dedicated “ECO” button activating their efficiency programming
Hyundai – An “Eco” button enables a specific efficiency mode altering shift points, engine power and A/C settings
Ford – Their “ECO” button initiates a computer controlled fuel saving mode shown to improve MPG up to 24%, depending on conditions
Chevrolet – Select models have an “Eco” button modifying throttle response and transmission shift points
Once a vehicle is equipped with eco mode, it takes just a button push to enable the programming and start saving gas. There will often be a light or indicator on the display cluster letting drivers know eco mode is active. Your driving habits ultimately influence just how effective it proves:
Tips for Using Eco Mode Effectively
While simply activating eco mode will net some benefit, you can maximize its fuel stretching performance with smart driving behavior:
- Accelerate moderately from stops – resists jackrabbit jumps by easing into speed
- Maintain steady cruising speeds whenever possible
- Allow plenty of room to decelerate gradually for traffic lights or signs
- Use cruise control religiously on highways
- Keep an eye on engine temperature to avoid overworking while in eco mode
- Reset to normal mode if you need rapid acceleration or hill-climbing ability
Essentially, pilot the vehicle as if there was egg resting on the gas and brake pedal! Gentle inputs reward you at the pump.
Now we know what eco mode is, when to use it, and how to maximize its advantages. But with the identified downsides and variability based on conditions, should everyone activate eco mode whenever possible?
The Bottom Line: Who Should Use Eco Mode?
Given that its benefits depend greatly on individual driving behavior and environments, eco mode is not universally advantageous across all drivers and locales. Based on our testing and research, here are the motorists who stand to gain the most from frequently running their vehicle in eco mode:
- Highway commuters and road trippers – The open road benefits are clearest here
- Suburban errand runners – More efficient than urban stop-and-go
- Nature lovers heading to national parks – Cruise smoothly taking in the views!
- Cost-conscious carpoolers and Uber drivers – Every MPG adds up quick
- Parents carting kids around town – Gentle all the way
- First-time teen drivers – Learn light-touch car control
- Discount shoppers hitting outlet malls – Gas savings fund a pretzel stop
Conversely, eco mode seems ill-suited and potentially detrimental for:
- Truck and van fleets – Overworked engines straining big loads
- Northern state residents – Sluggish accelerations risk getting stuck
- Classic car enthusiasts – Sacrificing visceral performance feels wrong
- Luxury sport sedan CEOs – Ruins the Maserati magic
- Carpoolers already running late – Throttle lag risks road rage
- Anyone driving in dense urban regions – Few benefits evident
As with most aspects of life, moderation makes the most sense. Eco mode has its benefits and drawbacks depending on intent and conditions. The most satisfied drivers use the setting sporadically when the opportunity makes sense, rather than forcing it in unsuitable situations. Think of it like a helpful friend – glad to have them join on a road trip, but they probably shouldn’t ride along on your weekly grocery battles!
Conclusion: Evaluate Then Engage Eco Mode
Eco mode aims to improve car fuel efficiency through engine and transmission modifications. How well it works depends greatly on steady driving conditions and moderate acceleration habits. Drivers can evaluate their own realistic efficiency benefit by testing MPG with the setting on and off.
While eco mode may compromise some performance and acceleration attributes, it provides gas savings mainly during highway and suburban cruising scenarios. Drivers in temperate regions taking frequent long trips appear to benefit most from eco mode.
Just beware of pushing the eco mode limits – don’t leave yourself power deficient entering risky situations. Employ it sporadically rather than forcing frugality at every turn. With smart evaluation of personal driving needs and a light touch behind the wheel, eco mode can pay dividends for many motorists looking to save at the pump!