Cars these days are practically overflowing with features, options, tech, etc. With this comes safer, more efficient, and more comfortable cars. However, these numerous new car features can also be overwhelming and confusing for some drivers. Adding to the confusion are all the gas-saving tips that are flying around these days. With that in mind, what is the deal with Eco mode? Does it actually save on gas? 

What is Eco mode? 

Selectable driving modes are a nearly ubiquitous aspect of the modern car. We first saw it in sports and supercars to give drivers a more low-key driving profile for around-town driving. These days, everything from Minivans to pickup trucks has multiple driving modes. 

What’s happening here is, the car’s ECU has multiple modes programmed in that change how the computer makes adjustments to throttle mapping that controls the engine performance, shift mapping for the transmission, and suspension. 

Consumer Reports says Eco mode is one of the more common driving modes in modern cars, which is meant to restrict fuel consumption, making the car more efficient, but does it work? 

Does Eco mode give you better gas mileage? 

Eco mode most commonly reduces throttle response and shifts earlier in the rev range to conserve fuel. What’s really happening is as simple as controlling your car’s RMPs to stay as low as possible. 

Consumer Reports decided to test it scientifically. They installed an inline fuel gauge to more accurately monitor the fuel consumption instead of just watching the normal fuel gauge.

CR tested Eco mode with city and highway driving. The reduced throttle response was easily felt while city driving. Eco mode certainly tempered the driving style; the pace of traffic was still king. So, the testers still had to push the test vehicles harder than the normal Eco mode preferred rev range.

“In past testing, we found no fuel economy benefit using Eco mode for city driving. That proved to be the case again in our more recent tests,” wrote Consumer Reports. 

This doesn’t come as much of a surprise—all the starting and stopping, along with bouts of vigorous acceleration to hang with traffic. 

CR says they always test fuel economy highway runs at an idealized 65 mph, with the transmission in its tallest gear. Even still, CR found the same results as the city driving test. Eco mode doesn’t have any significant impact on miles per gallon. Since highway driving doesn’t require nearly the same kind of hard acceleration and gear shifting as city driving, the Eco mode is worthless as a fuel-saving trick. 

Is Eco mode worth it? 

The little green button alone isn’t going to save you any measurable amount on gasoline. Its true value is in encouraging more mild, smoother driving habits, which in the long run, actually can affect fuel economy in a noticeable way. In that sense, Eco mode could be seen as more valuable as a “how to drive economically” training program. But don’t expect much help from simply hitting the leafy green button and continuing to drive the same.