If you buy the new 2013 Ford Fusion Hybrid, you’re likely a cost-conscious driver who wants to get the most mpg from each expensive tank of gas. The car has several technologies that will help you do that: engine start-stop and SmartGauge with EcoGuide, for example.

These aren’t unique to the Fusion, but a new feature called Eco Cruise is. It works like regular cruise control except, as the name suggests, it’s geared toward getting better fuel economy.  “We’re always brainstorming to come up with new features to give customers better fuel economy,” said Kent Hancock, a hybrid calibration engineer with Ford. “So when we were developing the new Fusion Hybrid, we came up with the idea of Eco Cruise.”

Hancock said that with the feature engaged, the driver will experience a more gradual acceleration when driving up an incline or reactivating cruise control. “It allows for a slight improvement in fuel economy, especially in hilly regions or when 'resume' is used and you have a 10 to 15 mph difference between your actual speed and your set speed,” he said. “With Eco Cruise, active acceleration will be fairly gradually, but with it off it’s much more brisk.”

That’s the trade-off and exactly what I experienced when trying the feature while driving in Los Angeles during a recent press drive of the Fusion Hybrid. The effect was quite noticeable on hills, and I don’t recommend it for aggressive L.A. traffic.

But if you want to squeeze every drop of fuel from a fill-up -- and don’t mind irate drivers piling up behind you -- it may help you gain a few mpg.