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Hypermiling in My Old Subaru…or "Life in the Slow Lane" |
16 Comments |
| By Steve Balogh in Conservation, Green Living, How To, Transportation | May 13, 2008 | ||
Well the price of gas has hit the magic $4/gal mark for regular in Syracuse, well, $3.999 to be exact. After the last fill up, I decided that I was sick of getting about 20 mpg or about 260 miles per fill up out of my old Subaru (a 2000 Forester). I decided to start trying out some basic techniques - I wouldn’t let the engine rev above 2000 rpm if I could help it. I would maintain a speed of no more than 3 miles over the speed limit, and no more than 60 mph. I wouldn’t accelerate into red lights, and would not idle the engine (except at traffic lights).I’ve traveled 245 miles since my last fill up, and the results so far are promising. I still have a 1/4 tank to go! Normally about 250 I had to seriously consider which gas station I was headed towards. I’d say that the techniques that I described above have increased my mpg (city + hwy) from ~20 to up around 24. This means that I am getting about 20% better gas mileage! I’ll know for sure, if I can squeeze the (13 gal x 24 mpg) 312 miles out of this tank. Pretty amazing results, if you think about it. 20% fuel economy improvement equals a free tank of gas out of every 5 regularly scheduled fill ups. This week I have some maintenance scheduled that should help boost the mpg even further, as there is a problem with the vacuum line in the fuel system (Damn “Check Engine” light!).To recap, here Balogh’s rules of the (expensive) road:
- Don’t let the engine rev above 2000 rpm, if you can help it. (You can pick your own number depending on make and model.)
- Maintain the speed limit, or no more than 3 mph above. Top speed of 60 mph. (This is tougher than it seems…)
- Do not accelerate into red lights or stop signs. (I do a lot of coasting now.)
- Do not allow car to idle (except at stop lights).
I challenge our readers to go out and give it a shot. Let me know how you do. For those who do not have a fancy onboard computer that figures out mileage, here’s how you do it:
Mark down miles on odometer upon fill up. You have to fill tank the entire way for this to work. The next time you get gas, fill the tank up completely again and note the new number on your odometer. Save your receipt from the gas station. Now you’re ready to compute mpg:(newest odometer reading [minus] old odometer reading) e.g. 109,635 - 109,392 = 243 miles.Divide this by the number of gallons on the last fill up, e.g. 243 miles [divided by] 12.2 gal = 19.9 mpg.
UPDATE: This site - cleanmpg.com linked to this article. Seems like a great place for people interested in improving their mileage to start. (I don’t condone any of the illegal techniques though…)UPDATE #2: Results posted here.
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Michael said,
Those are good tips! I tried all of the above with a 1996 Subaru Legacy wagon, in addition to the following:
-Checking tire pressure (I keep it 1-2 psi above the nominal pressure)
-Removing unnecessary cargo
I’ve found it reduces fuel consumption by about 15% compared to driving with a heavy foot. My average over the last 39,000 km (24,000 miles)–that’s over 85 fill-ups–has been 24.8 mpg (9.5 L/100 km). I get 1-2 mpg higher in summer and that much lower in winter. My record is a stretch of highway driving at 105 km/h (65 mph) with a slight tail wind: 685 km (425 miles) on 44.9 L (11.9 gallons) or 36 mpg.
links for 2008-05-14 at Family Freedom said,
[...] Hypermiling in My Old Subaru (tags: freedom) [...]
lou said,
i have a 2001 elantra
been getting around 40 mpg per tank some times over or just under
i jacked up my tire pressure to 40 psi, max is 44
stay below 60 mph usually 57 58 mph
draft anything bigger than the elantra vans trucks etc at around 61 mph
at stop lights that i know are long i turn off car. dont use drive ups any
more coast down long hills. time lights when able hardly ever brake. park
nose out hate backing over same real estate. longer walk but we all can use
a little excersize.
John D. said,
I don’t like the “drafting” recommendations just because to derive any mileage benefit, you end up too close to the vehicle in front of you. I try to stay as close to 55 mph as possible, and using the cruise control on ralatively flat and dry roads is the best way to do it. I like coasting (that is, taking foot off accelerator) on downgrades, allowing gravity to take the car up to around 60 mph, and only applying the gas again when the road levels out to maintain the 55mph speed. The best advice is to slow down on the highway, and coast up to traffic lights—the latter saves not only gas, but also brake wear—I have been doing both since gas hit about $2.50/gal in my area, and realized about a 20% increase in mpg.
lou said,
to clarify drafting thing its mainly trucks and im 5 skip bars behind which is about 100 to 125 feet which is almost in view of trucks side mirrors and i pop out time to time to let the driver know im back there. most time speed is 61 mph and i slow down if hes slows. when he starts pulling away i drop off and go back to 57 58 mph im also on the road early in the mornings 6am not much traffic to worry about. i dont do close in drafting too dangerous.
Chris Marasti-Georg said,
I bought a used ‘99 Forester a few months back, right after I learned about and started trying to hypermile. My first 5 tanks or so were around 25-26 mpg (it’s rated at 21/27). Since I’ve taken over from cruise control, and really worked on rounding out my hypermiling ability, I’ve been over 30 mpg on every tank, averaging around 31.
Vehicles never drive close enough to the speed limit around here to draft at a safe distance. I stick to the limit on flat, coast (in neutral) on downhills, perhaps going back into gear at the bottom to pick up a little speed if there is a coming hill. I set my foot on the pedal for the hill, between the amount of gas needed to maintain at level and the amount needed to maintain on the hill, so that I end up going up the hill a little bit slower, but not much. I watch traffic and lights ahead, and leave a comfortable pad between myself and the person ahead of me.
The best part to me is that I no longer feel like I will die in a fiery wreck. I used to make myself nervous sometimes, and that doesn’t happen any more.
melissa said,
I would like to know how you pick the number. For instance, when I bought my PT Cruiser the dealer told me to try not to let it rev over 3000 RPM.
Jason said,
I have an ‘02 Legacy that I can generally get about 30mpg from using a lot of these techniques.
One other thing that can help (in my opinion) is installing a high performance Air Filter such as one from K&N http://www.knfilters.com/. My whole family and a number of friends have installed either a K&N filter or some equivalent (e.g. TRD performance filters for Toyotas) and we all think it has helped.
K&N advertises them for improving power and acceleration by allowing less restrictive airflow, but they won’t make any claims about improved mileage, because that really depends on driving using these techniques. Assuming you drive to maximize mileage, an air filter that allows better airflow can be a good investment.
Michael d'Estries said,
As my ‘01 Forester is stick, I’ve been driving a lot in neutral — especially since Ithaca, NY is blessed/cursed with hills. It definitely helps — our ‘08 Civic (which is automatic) has also benefited from shifting into neutral on large hills or slopes. My old Hyundai used to lose power steering when I did this, so I tended not to use it too often — the new car, however, is good as gold.
One of the nice things with the new Civics (and I’m sure other cars) is the tire pressure monitor. No longer do you have to guess if it’s getting low — the car will just let you know.
And don’t think automakers aren’t paying attention to hypermiling - back in January, Groovy told you that Toyota is planning on installing a “driving efficiency” monitor that lights up the dashboard green when you’re getting the most out of your gas tank. At least it’s something to look at!
Update on Hypermiling - Improvement from 20.0 to 24.4 mpg! » GroovyGreen.com - Start Today :: Save Tomorrow said,
[...] Hypermiling in My Old Subaru… [...]
Gideon said,
Driving in neutral in an automatic can burn up the transmission. An old boss did that to his work car once; he used to put it in N coming down a long mountain road. I don’t know if newer cars have this problem.
Staying off the break and turning off the engine as much as possible (unless you need a new starter) make the biggest difference. A vehicles in Japan have an automatic shut-off when the car is stopped (it starts again when the gas is pressed), like the Prius.
Dennis said,
Two years ago as gasoline prices rose I backed off the accelerator. Instead of going at the upper speed limit I dropped my average speed 5 mph. I saw an 5 mpg improvement over three tankfuls. I dropped my average speed another 5 mph, not to exceed 55 mph and realized another 5 mpg increase. That was in a 1987 Subaru GL stationwagon (man. trans). When I parked it last November I was consistently averaging around 33 mpg each fill. I now am driving a 1995 Subaru Legacy L sedan 5 speed trans. at similar speeds and am consistently getting 35+ mpg. I maintain tire pressure at 40-42 psi (thats at the lower limit of the psi rating listed on the sidewall by the tire manufacturer.) I accelerate gently, cruise in the right lane and use synthetic oil.
I parked the 1987 in the back yard with 309k letting the license lapse. It still runs great but due to holes in the body barely gets warm inside in the winter. The 1995 has 212k, has a tight body, excellent drive train and runs great. I expect to exceed 300k with it also.
I’ve enjoyed 5 Subarus. I’ve owned the ‘95 twice. Our daughter owned it for four years. I love the AWD, reliability and economy. I see no need for an engine larger than 2.2 liters. Anyone who wants to race should get trained and go to a race track.
mark said,
I’m on my second Forester (’07) with the 4 speed automatic, so I’m limited compared to a stick. Staying at or below the speed limit is not difficult. A big help is beginning the trip early and not being in a rush. 50 is generally better than 60 due to aerodynamic drag. Speaking of that, removing the roof rack when not in use may help a tad. Keeping the windows up also helps a bit, as well as saving your hearing. Limit the use of headlights. Keep the motor in tune, and use the best oil you can afford. I use synthetic. It stays slipperier longest and markedly reduces the buildup of gunk on the internals. I had to have the head gasket replaced on one side of the previous Forester at 90K and the mechanic said it looked like new inside, so he checked a few things with a micrometer and they were within spec for new parts. I’m sold.
The numbers don’t lie! Hypermiling works! » GroovyGreen.com - Start Today :: Save Tomorrow said,
[...] Hypermiling in My Old Subaru… [...]
Segwyne said,
This is the first time I have heard the term hypermiling, but I guess I have been practicing it for a while now. I admit to driving 5 over the limit, and including taking it to 70 on the interstate, but I try not accelerate or decelerate any faster than necessary. I just checked the numbers for my car (a 1998 Mazda Protogé, automatic transmission) and I get much better mileage than they show. Last time I checked it, I was getting 37-38 mpg. Now granted, I use the car primarily for long trips, so 95%+ of that is highway mileage. So, yeah, it does work. I haven’t tried making only right hand turns yet, though.
Peacedog said,
Yes, you saved yourself 4mpg. But you made yourself look like a little old lady doing it. Good, irony intended, for you.
It amazes me how stupid normally intelligent people get trying to save a few bucks.
Hey, you could save all that money by riding a bicycle everywhere. (Along with all of the other unemployed granola munchers)