By P.R. Ganapathy
On my ride to work recently, I heard an NPR interview on the subject of fuel conservation. The experts on the panel offered some tips for improving fuel efficiency while driving, and so I decided to try them out. Like most people out there, when fuel climbs to $4.87 a gallon I can't change my car to a Prius; I'm just going to have to do more with less.
Here are some of the suggestions they offered, and my experience trying them out.
1. Measure your mileage. If you don't know where you are, you can't know where you're going – the first step to any improvement process is to create a baseline – and then improve from there. So start off by noting your odometer reading (or zeroing the trip meter) the next time you fill up, and then noting how many miles you've driven when you fill up again. The difference, divided by the gas you put in (full tank-to-full tank) gives you your mileage. If you're fortunate to have a fancy car that shows you instantaneous and trip mileage, use it!
2. Reduce speed. This is supposed to be the simplest and most effective way of improving fuel consumption – and boy, did it work for me. By driving at not more than 55 mph, I saw my average consumption rise from 23-24 mpg (unfortunately, I drive a rather gas-guzzling 4-wheel drive VW) to 27 mpg, even getting as much 29.8 mpg on one day. For my 22-mile commute, it added perhaps 5 minutes to my commute time.
3. Turn off the air conditioner. The television show "Mythbusters" tried to examine the myth that driving with your windows down and A/C off is less efficient than driving with your windows up and A/C on. I didn't watch the episode, but it appears that driving with the A/C off is better. I tried driving with the A/C off and windows up, and it might have given me 2 mpg more than with the A/C on. I must admit that it has been quite difficult these last few weeks, and I sometimes put the A/C on while coasting downhill (when consumption is excellent).
4. Drive smoothly. I've never been one of those drivers who like to verify that their cars are accelerating from 0-60 in 6 seconds at every red light, but I've been particularly careful about slow acceleration during this experiment. Stops and starts, and the acceleration during the start, have the greatest impact on fuel efficiency, so reducing them to the minimum (if you see a red light, slow down early enough and it might change by the time you get to it) and then accelerating slowly help get better mileage. If you see congestion ahead, slow down well in advance (like the trucks do) to try to avoid having to decelerate and then accelerate again.
5. Use public transit. I tried using public transit a few times. There's a direct AC transit bus line from my office in the Peninsula to my home in the East Bay, so I thought it would be pretty efficient. Unfortunately, the time it takes just made it an non-viable option. 511.org has a good transit trip planner, and trips from home to work or vice versa took 1:20 vs. 25 minutes in the car. Even with the savings, I couldn't justify this time differential. If I get into the habit of working on the bus (it has WiFi), then the equation can shift in favor of public transit.
6. Car Pool. This one's really working well for me. I'm fortunate that a colleague who's equally conscious of the environment impact and cost of driving alone lives close-by, and both of us have enough flexibility in our work schedules to permit car-pooling. This has cut my gas bills by around 30% (I can't car-pool every day of the week – if I could, I'd probably see a 40-50% saving). 511.org has an excellent "ridematch" finder – just plug in your home and work address, the days of the week that you can car-pool, and the time that you leave for work and return home. Ridematch will suggest people who live where you live, work where you work, and work the same hours, you can then contact them and arrange a car-pool. No more excuses!!
7. Keep your car well maintained. Keep the air filter clean, inflate the tires, and do all the sensible things that make for maximum efficiency.
All told, most of these changes have been relatively painless (except keeping the A/C off), and I've been happy with the results. I'd appreciate any feedback from trying them, additional suggestions! Buckle up, and drive slow!
UPDATE: Here is an excellent article on eco-driving, or how you can conserve energy while driving your car.