First thing: Have you driven an electric car? If you’ve lived with one for a time, then you likely have some solid ideas of your EV’s best features. Those who have just done a few test drives or haven’t driven electric at all could use some illumination. So here you go.
1. Hey, speed racer! Most electric cars boast pretty impressive acceleration from a stop. Unlike an internal combustion engine, electric motors generate 100 percent of their torque right out of the gate, which means your launch from standing still can be much more aggressive than you would imagine. We’re not saying you should do this as a matter of course…just that it’s kinda fun to know that capability exists.
2. Charging is way cool. Really. There’s nothing like parking your car for the night, plugging in, and starting the next day with a full ‘tank’ of energy on board. Just imagine life without the need to stop at a gas station. If you’re able to sign up for an electric vehicle rate plan from your electric utility, then set your charging to take place at non-peak hours overnight. You’ll have a full charge in the morning at the least possible cost. Plus, an ever-expanding network of public chargers is available for charging away from home, and while many now require a fee, a great many still provide energy for free. So, benefit from the kindness of strangers.
3. Electric vehicles are quiet, so enjoy your solitude. In the early days of EV development during the 1990s, there were unexpected noises to contend with like gear whine, high frequency noise from motor controllers, and such mundane things as the sound of tires contacting pavement and wind rushing past the windshield. Really. The familiar sound of internal combustion that normally masks the everyday sounds of motoring was notably absent. Over the years electrics have been engineered with better and quieter controllers, additional soundproofing, and other engineering measures to create the quiet EVs we have today. Experience the Zen.
4. EVs are extraordinarily efficient so you’ll be saving money every mile you drive, compared to driving on gas. The exact amount varies since gasoline and electricity costs differ by state, region, and city. A recent analysis by the Department of Energy indicated the national average for a gallon of gas was $2.74 compared to $1.21 for an ‘eGallon.’ DOE’s calculations factor the cost of fueling with gas compared to a similar vehicle that runs on electricity. The difference is even more dramatic in California, where I recently fueled up with standard grade gas at $4.59 per gallon. I was glad to get behind the wheel of an electric at the earliest possible opportunity.
5. Driving electric is like being in an immersive game. You have an extraordinary level of influence over your car’s efficiency with instrumentation providing continuous feedback on your driving and how this is affecting range. That’s not as critical in an EV with a 250-mile range capability as it is in one that can go only 90 miles on a charge, but that doesn’t matter. You’ll find yourself intrigued by your car’s instant feedback on energy usage, battery status, and distance-to-empty. There will be times when you will consciously (or unconsciously) adjust acceleration, speed, and downhill coasting to eke out more miles on that constantly recalculating distance readout, since more efficient use of on-board energy adds miles in real-time. Backing off the accelerator early and coasting up to a red light to maximize regenerative braking that feeds energy to the batteries is also human nature for an EV driver. Game on!
Mazda’s innovative and award-winning SKYACTIV suite of technologies continues to expand, this time in the 2014 Mazda6. Powered by a 2.5 liter SkyACTIVE-G gasoline engine, this fun and sophisticated mid-size sedan now features an available i-ELOOP regenerative braking system that adds to the car’s impressive fuel efficiency, boosting its official EPA ratings to an estimated 40 mpg on the highway and 28 mpg in the city, for a combined 32 mpg.
Those are pretty good numbers for non-hybrid small cars, but exceptional for a conventionally-powered mid-size model. This efficiency enables up to 650 miles on a single tank of gas. If you drive the average 15,000 miles each year, that means your visits to a gas station could be limited to every two weeks or so, depending on your driving habits.
Mazda’s i-ELOOP – for Intelligent Energy Loop –is not a hybrid system since recovered braking energy is not used for acceleration assist or electric-only operation. It’s also different because, unlike other regen systems that store recouped electrical energy in batteries, i-ELOOP uses a supercapacitor. The system’s double-layer capacitor can be discharged and recharged many more times than batteries with far less deterioration and will likely last the life of the car.
When a driver lifts off the accelerator pedal, i-ELOOP recovers kinetic energy as the vehicle decelerates. A variable voltage alternator generates electricity up to 25 volts for maximum efficiency before sending it to the supercapacitor. A DC/DC converter steps down the supercapacitor's output from 25 volts to 12 volts for use in the car’s exterior lighting, climate control, audio system, and other electrical components. This reduces the need for a normal engine-driven alternator to generate the electricity required to run these systems, a real benefit since a conventional belt-driven alternator’s parasitic load on an engine decreases fuel efficiency.
In urban driving with frequent acceleration and deceleration, i-ELOOP can provide nearly all of the electricity these systems require. Headlamps and other exterior lighting, heating/air conditioning, wipers, and the audio system account for about a 40 amp draw, within the capabilities of the DC/DC converter’s maximum throughput of 50 amps. On a cold day, particularly right after starting, it’s possible the defogger and optional seat heaters may exceed the DC/DC converter's capacity, in which case the electrical system reverts to conventional alternator-powered operation and bypasses the capacitor system completely.
At times when available e-ILOOP-generated electricity exceeds the electrical load, electrical energy charges the car’s 12 volt battery. When no regenerative braking energy is available, the alternator charges the battery but now through the DC/DC converter. Battery capacity is unchanged since it must still start a cold engine when the supercapacitor is not charged.
Supercapacitors accept and release charge very rapidly and only store electricity temporarily, so they must be topped off before each stop. However, it takes just a few seconds to fully charge the capacitor. The Mazda unit can accept a full charge in just 8 to 10 seconds. Although it can discharge in as quickly as 40 seconds, discharge may take up to 113 seconds at minimum load.
Mounted beneath the hood, the cylindrical supercapacitor is 13.8 inches tall, 4.72 inches in diameter, and weighs just 13.2 pounds, with its required heavier wiring harness weighing in at 3.3 pounds. Mazda says that the e-ILOOP system brings an approximate 5 percent fuel efficiency improvement under real-world driving conditions, which contributes to the Mazda6 achieving its best-in-class EPA fuel economy rating.
The i-ELOOP system in the Mazda6 is part of an available GT Technology Package that also includes Mazda radar cruise control with forward obstruction warning, lane departure warning, high beam control, and active grille shutters. All this extra goodness comes at a cost of $2,080, bringing additional SKYACTIV technology to the road that helps deliver impressive fuel efficiency while attending to the performance and fun-to-drive nature expected of the brand. Want to know more? Watch the video here.
There’s more to come. Soon, the 2014 Mazda6 will also offer a 2.2 liter SkyACTIVE-D clean diesel engine, Mazda's first diesel in the North American market. Plus, the Mazda i-Stop stop/start system that’s available in markets outside the U.S. is in the pipeline for the States. Mazda reportedly will introduce this system here in the Mazda6 in 2016.