Having worked most of the kinks out of my Prius plug-in conversion kit, and learned to better manage its numerous idiosyncrasies, I set out to obtain maximum mileage from a tank of gas. The car has an eight gallon tank (or that’s a normal fill-up) which will usually take me about 400 miles. I wanted to see how much better I could do by maximizing use of the batteries.
Plug in cars haven’t exactly taken over the marketplace, but the capability of these cars is legit. Regular readers of this blog know that my car is an older, out of warranty Prius with an aftermarket plug in kit that will take it an (optimistic) maximum of 20 miles without gas. But a brand new plug in Nissan Leaf can go 80+ miles. That’s a pretty good daily range for most people, and it only costs about 3 cents/mile in fuel to do so. Compare this to a typical 25 mpg car which burns about 14 cents/mile in fuel (assuming $3.50/gal). However, rightly or wrongly, people are wary of all electric vehicles. The technology that does seem to be working for the marketplace is the gas/electric hybrid – the full electric suffers from something called ‘range anxiety’ (this is just a fancy way of saying you’re worried you’ll run out of battery on the Long Island Expressway, and you won’t be able to go get a can of electricity in time to be back before someone steals your alloy wheels).
But 20 miles of range is plenty for me. My car plugs into a regular household outlet, and the batteries take about 3 hours to charge. A typical day means the electrons need to carry my wife down to the beach at 5:30 AM for Boot Camp (during which time I attend Sleep Camp); the kids to school, which is on my way to work; and me back home, with maybe a quick errand or two. This adds up to about 15 miles. Hypothetically, with my 4 kW kit from Plug-in Supply, I could do this 100% electrically. However, as a practical matter, the gas engine will always run a little. It will run just to warm up the catalytic converter (uh huh – you read that right. No – it does not make sense). It will run just to ‘protect itself’, which means that it wants to be warm in case you need to floor it if there’s a bear attack. And it will run if you turn on the air conditioning or defroster. But usually I can complete this loop with the mpg meter pegged at 100mpg - which is as high as it goes - for the majority of the time. Freeway driving takes a lot more power, and the batteries aren’t as much help for that, so when I go to the airport or to a meeting in town, I’m pretty much back to normal mileage.
I was doing great on my last tank, with the mileage meter showing a nice 65 mpg average, on the home stretch towards a 500+ mile tank. That’s when it happened – I forgot to plug in the car. It’s kind of odd if you think about it, to grab the extension cord of your car and plug it in, and I’m just not that used to it yet (the other thing everyone says you will do, and indeed I have done this once, is drive off without unplugging).
So I forgot to plug in for the last two trips that would have gotten me my max average ever, and now I have to start again on the next tank. I’m going to keep trying, and you can see my progress here.
How ‘bout you? Have you considered a full electric plug-in vehicle, or a plug-in hybrid? In my opinion, hybrid technology, which recaptures energy from braking, makes a lot of sense, especially for stop and go driving. Adding to the hybrid function by precharging the batteries, plug-in hybrids may well catch on – heck, it’s nice to have your own gas station in your home. And if you have solar PV, you can even become your own power provider, giving the idea even further allure.