Update in 2014: We’ve now had our hybrid car for six years, and we still love it!  It saves us even more money now that gas prices have risen; I updated the money-saving calculation below.  There are now several models of Prius available; the one we have seems most similar to the “midsize”.  I still do my daily commute by public transit, now with a new baby!

In this new year, I’ve been evaluating some things from the past year: our grocery spending, my favorite songs, and now our car’s mileage and fuel consumption.  Sure, hybrid cars are advertised as saving a lot of gas, but are they really that great in real-world conditions?

We’ve had our Prius for a little over three years, and I’ve raved about it before, but until now I’d never bothered to add up just how much gasoline we’re using to drive how many miles in a whole year.  The futuristic dashboard computer tells us our average fuel economy in 5-minute increments and for the past few hundred miles, but what’s our overall average?  We’ve always kept a small notebook in the pocket of the driver’s door, where we write down the odometer reading and number of gallons every time we buy gas, so all I had to do was a little arithmetic.  (Yes, I did do it by hand!  Then I checked it with a calculator.  I had made one error.)

We drove 6,598 miles in 2010. That sounds like a lot!  We took road trips from Pittsburgh to Ottawa, Columbus, Philadelphia, and Albany, so those add up.  In fact (hang on while I do some Google Mapping and more math), those trips alone were 3,218 miles, so local errands and shorter trips made up only half of our total driving.  We live in a walkable neighborhood, and I do my daily commute by public transit, and Daniel generally works from home. Our six-year-old raised in this lifestyle can walk a mile almost without noticing.

We bought 170.53 gallons of gasoline in 2010. That also sounds like a lot–visualize 170 gallon jugs stacked together!  And that’s eternity in our tank; once we burn that gas, it’s gone forever.  The fact that we could be doing worse really is not all that comforting to me.

Still, we’re doing the best we can, driving the most fuel-efficient vehicle on the American market* and usually resisting the urge to hop into the car when we could walk, ride a bus, or carpool.  (One of my resolutions for 2011 is to get ready for church in a more timely manner so that we don’t wind up driving there–less than one mile–just because we’re late!)  The average American driver drives 13,476 miles per year*, so we’re driving about half as much as average–no, wait, there are two of us sharing the car, so each of us is driving about one-fourth as much as the average American. For the miles we drove, we averaged 38.69 miles per gallon. I can’t find a handy figure on the average mpg of the average vehicle on the roads, but it seems a lot of family sedans get about 25 mpg; compared to driving one of those the same number of miles, we saved 93.39 gallons of gas in one year, and at $3.70 a gallon that means we saved $345.54.

*Updates: There are now a few more efficient vehicles in some of the size classes, although the Prius still ranks right up there.  The page where I found the average miles per year no longer exists, and I couldn’t find a new reliable source for that information, although I did find other pages citing the same number.  I found a table of average fuel efficiency that, if I’m reading it correctly, shows 23.3 mpg for the average car actually on the roads in 2012.

Hey, wait a minute, that link says the Prius gets 50 mpg, not 38!  Well, that’s what I mean about the real-world conditions:

• We live in a mountainous area.  It takes extra energy to climb so many hills.
• Most of our local trips are very short.  We often spend several weeks within a three-mile radius of our home.  Driving the Prius for just five or ten minutes doesn’t allow it to reach full efficiency.
• Here in the city, there are lots of stop signs and red lights and pedestrians crossing the streets, so we rarely get long stretches of travel.
• We live in a climate that is pretty cold about four months of the year, and we park outdoors.  We can see on the dashboard computer that the Prius is less fuel-efficient in cold weather, especially in the first five minutes.
• Daniel started driving only six years ago and still tends to accelerate and brake suddenly, which uses more fuel than more gradual changes in momentum.

We have relatives and friends who drive Prii in flatter, warmer places, and we’ve ridden in my parents’ Prius in Oklahoma watching the dashboard mpg with envy!  Our hilly terrain and heavy traffic make more use of the nifty regenerative braking, though.  Here’s a helpful article on how to maximize Prius mileage.  Here are ways to use less gas driving any kind of vehicle, not just hybrids.

My point is, we’re not even using our Prius at anywhere near its maximum fuel efficiency, but it still saves lots of gas compared to a regular car! Driving longer to maximize miles per gallon would mean more driving, which would actually use more gas overall.

My other point is, we save even more gas by walking and taking transit and sticking close to home most of the time.  My commute alone would add about 1,440 miles per year and about 37 gallons to our total, if I did it by car.  Meanwhile, we get plenty of exercise, get to window-shop and smell the flowers, and often see friends on the sidewalk or bus.  It works for me!

Visit Waste Not Want Not Wednesday and Fabulously Frugal Thursday and Thrifty Thursday for more money-saving ideas!