Simple "Hypermiling" techniques that WORK
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Simple "Hypermiling" techniques that WORK
Okay, I just posted up 39.2 mpg on the board and blew everyone away by 10%... and will probably top that by another 5% the next time I fill up. Yeah, part of it is the car... but I've proven to myself that it's pretty easy to get 32 mpg in this car, and even 30 or less if you're just flogging it around town and having fun. My worst "city" tank ever was 28.5 mpg (first tank when I bought it)... best city tank is 38.5... that's a 35% increase!!! So, I've become more than convinced that like so many other things that we do in a car (road racing, autocross... even drag racing), it's the DRIVER that makes the difference in fuel economy and I feel obligated to do my part and try to share some of what I've learned.
You'll read a ton of stuff about hypermiling techniques, and if you get into it, most of them work to some degree. What I'm going to present here is SIMPLE, basic, common sense stuff that just plain works. And it applies to ANY car, not just an econobox. We all know we can get LESS than the EPA mileage estimate for our vehicle... try using some of the techniques below and you'll find that you can get 10-20% MORE than the EPA estimate.
1. Slow Down! Yeah, it's no fun, but neither are speeding tickets and spending another $4 on another gallon of gas. Just chill out and slow down. Drive the speed limit or at least the slowest you can get away with and not impede traffic. Resist the urge to pass the car in front of you "just because it's there". Leave your ego at home. It's hard for us competitive types to do that... but keep in mind your goal of improving your fuel economy and paying less for gas. Forget about the moron who can out-accelerate you in his riced out Honda, you've got better things to spend your money on. If you can change your habits from driving 10-15 mph over the speed limit (typical for this area) to driving within 5 mph of the speed limit, you've lowered your speed by 15% (slowing from 42 to 35 is 15%... 72 to 60 is also 15%). That translates DIRECTLY into fuel savings. At least 10%. And the funny thing you'll notice is that unless you're on a highway road trip where you're not impeded by traffic or stops, you'll still get where you're going in about the same time. (for long road trips, it might take you 15-20% more time to get where you're going... you'll have to decide if that's worth it or not)
2. Accelerate more gently. Again, absolutely no fun. But, here's the thing... 10-20% of your fuel is wasted in acceleration. This is THE single hardest thing to do, but it makes among the biggest differences! They've been telling us since the 70's to "avoid jackrabbit starts". Dammit, they're right. If at all possible, just creep through the gears. Worried about what other traffic thinks? (remember, leave the ego at home) Try just accelerating a tick slower than the other cars around you. Not enough to be annoying... just enough that if they wanna go faster, they'll know they need to be in another lane! Another good trick is to reverse your "competitive urge" to be FIRST at the traffic light... yeah, you've probably been doing it since you were 16 just like I have. Having people in front of you at a light allows you to easily "get away with" accelerating more slowly without hindering anyone.
3. Use a higher gear and "cruise". Those of us who have driven stickshifts since the dawn of time generally like to be in a gear where we know we've got power to accelerate if we need to. Forget it. Drop into the highest possible gear as soon as you reach cruising speed. My Yaris will happily cruise in 5th at anything about about 32 mph... and sip fuel doing it! Use this in conjunction with #2 above. If your target speed is 40 mph, just slide through 1st, 2nd and 3rd (never exceeding... <gasp> 2500 rpm) and drop into 5th at about 35, squeaking that last bit of acceleration ever so gently out of 5th gear. (not giving enough throttle to lug it or anything... just "lean" on it a little bit) Whether you're cruising in 5th or 4th, the object is to establish a "cruise" and hold it as smoothly as you can. Don't let the other traffic goad you into speeding up when you don't need to, just concentrate on keeping a nice light foot on the throttle, just enough to barely maintain your target speed.
4. Coast. This is another biggie. You can gain another easy 10% just by mastering this skill. In some cars, like my Yaris, the ECU has a feature called "DFCO" (deceleration fuel cut-off) that completely shuts the fuel injectors off when you lift off the throttle in gear with the RPM's high enough (anything over about 1200... below that, the fuel injectors come back on to keep the engine idling) using NO fuel. Check and see if your car has this feature, if it does, USE it. How? Just lift completley off the throttle whenever you can! Whether you have DFCO or not, you still want to coast where you can. Since you've adopted a slower and more casual driving style, you're leaving more space between you and the car in front of you, and you're aware of what's going on ahead of you... you'll spot that the light 3 blocks ahead just turned yellow and you know you're going to have to stop. COAST. If you have DCFO, start downshifting (resist the urge to rev-match!) to keep the revs up and use NO fuel. If you don't have DFCO, just clutch in and coast. You want to get as much "free mileage" as you can. Do the same thing when you're driving somewhere that has hills you can coast down. (even urban areas in FL have a lot of overpasses) As you crest the hill, ease on the gas a little bit and give yourself an extra 5 mph or so... then LIFT and get some free mileage. Even if it's just 1/8 mile, ever bit of distance that you can cover for "free" adds up.
5. Maintain Momentum. This goes hand in hand with coasting, and you'll have to learn to balance it with traffic and circumstances. If you're approaching a light that's red and you have a good idea that it's about to change... try to adjust your speed so that you carry as much speed as you can (even if it's just 5 mph) and avoid STOPPING for the light. Every mph that you conserve is less acceleration that you'll have to do... remember, acceleration is where 10-20% of your fuel goes! So, maintain momentum where you can. But, if you're coasting (see above), you may find that it's beneficial to USE THE BRAKES to slow down a bit well before you reach an obstacle (such as a light, or a car in your lane making a turn) so that you can maintain 20 mph of momentum rather than having to scrub off MORE speed at the last second and only maintain 10 mph of momentum. A little bit of forethought goes a long way here.
6. Avoid Short Trips. Having the ScanGauge in my car has made one thing painfully obvious. It takes at least 3 miles for the car to warm up and for the average mileage to recover from the awfulness of a cold start. Even a lukewarm start is better than a cold start, so... like they've been telling us since the 70's again... combine your errands into as few trips as possible. My wife drives barely 3 miles to work every day and she has to make an extreme effort to get more than 26 mpg... in a base model MINI Cooper! She had exactly the same issue in her former car, a Saturn SL1 that got her 23 mpg consistently. (but would turn 32 mpg on the highway every time) Short trips are evil.
7. Maintenance. You guys know this. Oil changes with quality oil... try some of the new super-thin synthetics if you have a newer car. If your car will use 5w30, it should be fine with 0w20 or 5w20... it makes a difference. Synthetic oil in the transmission and diff. Tire pressures on the high side. Crazy high pressures like the hypermilers run aren't necessary, but something within the max pressure of your tire is good. I set mine to about 42 for autocross and just leave them there.
Now, you'll notice that I didn't suggest doing anything extreme. No shutting the car off when you're coasting (Forced Auto Start, they call it), or shutting the car off when you're stopped at a light, no fucking drafting behind other vehicles or other silliness. No driving 10 mph BELOW the speed limit. Just driving smarter. As much as 35% better fuel economy simply by driving smarter. The trick is to incorporate all of these techniques together for overall efficiency. YMMV.
You'll read a ton of stuff about hypermiling techniques, and if you get into it, most of them work to some degree. What I'm going to present here is SIMPLE, basic, common sense stuff that just plain works. And it applies to ANY car, not just an econobox. We all know we can get LESS than the EPA mileage estimate for our vehicle... try using some of the techniques below and you'll find that you can get 10-20% MORE than the EPA estimate.
1. Slow Down! Yeah, it's no fun, but neither are speeding tickets and spending another $4 on another gallon of gas. Just chill out and slow down. Drive the speed limit or at least the slowest you can get away with and not impede traffic. Resist the urge to pass the car in front of you "just because it's there". Leave your ego at home. It's hard for us competitive types to do that... but keep in mind your goal of improving your fuel economy and paying less for gas. Forget about the moron who can out-accelerate you in his riced out Honda, you've got better things to spend your money on. If you can change your habits from driving 10-15 mph over the speed limit (typical for this area) to driving within 5 mph of the speed limit, you've lowered your speed by 15% (slowing from 42 to 35 is 15%... 72 to 60 is also 15%). That translates DIRECTLY into fuel savings. At least 10%. And the funny thing you'll notice is that unless you're on a highway road trip where you're not impeded by traffic or stops, you'll still get where you're going in about the same time. (for long road trips, it might take you 15-20% more time to get where you're going... you'll have to decide if that's worth it or not)
2. Accelerate more gently. Again, absolutely no fun. But, here's the thing... 10-20% of your fuel is wasted in acceleration. This is THE single hardest thing to do, but it makes among the biggest differences! They've been telling us since the 70's to "avoid jackrabbit starts". Dammit, they're right. If at all possible, just creep through the gears. Worried about what other traffic thinks? (remember, leave the ego at home) Try just accelerating a tick slower than the other cars around you. Not enough to be annoying... just enough that if they wanna go faster, they'll know they need to be in another lane! Another good trick is to reverse your "competitive urge" to be FIRST at the traffic light... yeah, you've probably been doing it since you were 16 just like I have. Having people in front of you at a light allows you to easily "get away with" accelerating more slowly without hindering anyone.
3. Use a higher gear and "cruise". Those of us who have driven stickshifts since the dawn of time generally like to be in a gear where we know we've got power to accelerate if we need to. Forget it. Drop into the highest possible gear as soon as you reach cruising speed. My Yaris will happily cruise in 5th at anything about about 32 mph... and sip fuel doing it! Use this in conjunction with #2 above. If your target speed is 40 mph, just slide through 1st, 2nd and 3rd (never exceeding... <gasp> 2500 rpm) and drop into 5th at about 35, squeaking that last bit of acceleration ever so gently out of 5th gear. (not giving enough throttle to lug it or anything... just "lean" on it a little bit) Whether you're cruising in 5th or 4th, the object is to establish a "cruise" and hold it as smoothly as you can. Don't let the other traffic goad you into speeding up when you don't need to, just concentrate on keeping a nice light foot on the throttle, just enough to barely maintain your target speed.
4. Coast. This is another biggie. You can gain another easy 10% just by mastering this skill. In some cars, like my Yaris, the ECU has a feature called "DFCO" (deceleration fuel cut-off) that completely shuts the fuel injectors off when you lift off the throttle in gear with the RPM's high enough (anything over about 1200... below that, the fuel injectors come back on to keep the engine idling) using NO fuel. Check and see if your car has this feature, if it does, USE it. How? Just lift completley off the throttle whenever you can! Whether you have DFCO or not, you still want to coast where you can. Since you've adopted a slower and more casual driving style, you're leaving more space between you and the car in front of you, and you're aware of what's going on ahead of you... you'll spot that the light 3 blocks ahead just turned yellow and you know you're going to have to stop. COAST. If you have DCFO, start downshifting (resist the urge to rev-match!) to keep the revs up and use NO fuel. If you don't have DFCO, just clutch in and coast. You want to get as much "free mileage" as you can. Do the same thing when you're driving somewhere that has hills you can coast down. (even urban areas in FL have a lot of overpasses) As you crest the hill, ease on the gas a little bit and give yourself an extra 5 mph or so... then LIFT and get some free mileage. Even if it's just 1/8 mile, ever bit of distance that you can cover for "free" adds up.
5. Maintain Momentum. This goes hand in hand with coasting, and you'll have to learn to balance it with traffic and circumstances. If you're approaching a light that's red and you have a good idea that it's about to change... try to adjust your speed so that you carry as much speed as you can (even if it's just 5 mph) and avoid STOPPING for the light. Every mph that you conserve is less acceleration that you'll have to do... remember, acceleration is where 10-20% of your fuel goes! So, maintain momentum where you can. But, if you're coasting (see above), you may find that it's beneficial to USE THE BRAKES to slow down a bit well before you reach an obstacle (such as a light, or a car in your lane making a turn) so that you can maintain 20 mph of momentum rather than having to scrub off MORE speed at the last second and only maintain 10 mph of momentum. A little bit of forethought goes a long way here.
6. Avoid Short Trips. Having the ScanGauge in my car has made one thing painfully obvious. It takes at least 3 miles for the car to warm up and for the average mileage to recover from the awfulness of a cold start. Even a lukewarm start is better than a cold start, so... like they've been telling us since the 70's again... combine your errands into as few trips as possible. My wife drives barely 3 miles to work every day and she has to make an extreme effort to get more than 26 mpg... in a base model MINI Cooper! She had exactly the same issue in her former car, a Saturn SL1 that got her 23 mpg consistently. (but would turn 32 mpg on the highway every time) Short trips are evil.
7. Maintenance. You guys know this. Oil changes with quality oil... try some of the new super-thin synthetics if you have a newer car. If your car will use 5w30, it should be fine with 0w20 or 5w20... it makes a difference. Synthetic oil in the transmission and diff. Tire pressures on the high side. Crazy high pressures like the hypermilers run aren't necessary, but something within the max pressure of your tire is good. I set mine to about 42 for autocross and just leave them there.
Now, you'll notice that I didn't suggest doing anything extreme. No shutting the car off when you're coasting (Forced Auto Start, they call it), or shutting the car off when you're stopped at a light, no fucking drafting behind other vehicles or other silliness. No driving 10 mph BELOW the speed limit. Just driving smarter. As much as 35% better fuel economy simply by driving smarter. The trick is to incorporate all of these techniques together for overall efficiency. YMMV.
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Last edited by Loren; 07-15-2008 at 06:54 AM. Reason: DCFO != DFCO
