What better way to pass time that to take a long Summer road trip? However, nowadays, you have to think about fuel too. There’s a solution for those of use that like to drive hard.

Named after the green fruit, the PLX Kiwi from PLX Devices is a small device (a little more than 2 inches by 3 inches) that attaches to your dashboard or windshield.

By plugging into a vehicle’s diagnostic port, it can display miles per gallon as well as trip information and even the cause of engine problems.

But really it’s designed to make your driving habits more energy-efficient.

Accelerating hard and jamming on the brakes to slow consumes more gas than a smoother, steadier way of driving.

The PLX Kiwi shows off feedback on how you’re doing in that regard and gives you a “kiwi score.” It’s also programmed with 20 increasingly difficult challenges to optimize your score.

Making changes to driving patterns can lower gas consumption by 20 percent with gas at $4 a gallon, according to the company. That savings can go up to 33 percent if your driving is mostly on highways.

Depending on the type of car you drive, the savings can be several hundred dollars a year, between $560 and $800, according to the company. You can get a read-out of dollars saved on a given trip and a cumulative total.

For the eco-conscious driver, these foot pedal changes can add up: a sedan driver can reduce carbon dioxide emissions by 16,000 pounds. That’s the equivalent of changing out 500 incandescent light bulbs for more efficient compact fluorescents.

Another in-car display designed for fuel efficiency is the ScanGuage II, which doesn’t have the same slick LED display as the PLX Kiwi or the scoring system.

The PLX Kiwi will be available later this month and costs $299, according to a company representative, while the ScanGuage costs $169.

Now, I only need a Driving LED Emoticon and I am ready to hit the road!