Hypermileage - cleanmpg.com

[honda03842]

This website was suggested to me during a discussion of ultragauge on the Scamper's forum. It describes driving techniques to improve mpg. If you go to this article and page down to section 2 you'll see many suggestions.


Beating the EPA - The Why’s and How to Hypermile - CleanMPG Forums

Norm

[Kevin K]

• Do not accelerate quickly or brake heavily: This reduces fuel economy by as much as 33 percent at highway speeds and 5 percent around town. EPA tests do not account for this kind of vigorous driving.
• Do not idle if not necessary: Decreases average FE. The EPA city test includes idling and in many cases, it is not necessary. Consider shutting down your vehicle if stopped for more than 7-seconds as that is all the fuel it takes to restart a modern day, fuel-inject engine.
• Avoid driving at higher speeds: This increases aerodynamic drag (wind resistance) and mechanical friction which reduces fuel economy. The EPA test accounts for aerodynamic drag up to highway speeds of 60 mph, but most exceed that speed far more often then necessary.
• Cold weather and frequent short trips reduce fuel economy, since your engine doesn't operate efficiently until it is warmed up. In colder weather, it takes longer for your engine to warm, and on short trips, your vehicle operates a smaller percentage of time at the desired temperature. Note: Letting your car idle to warm-up does not help your fuel economy, it actually uses more fuel and creates more pollution. Drive to your furthest destination first and then as you are heading home, stop at the closer destinations in order from furthest to closest as the car is warmed up for longer portions of your drive.
• Remove Cargo or cargo racks: Cargo and/or racks on top of your vehicle (e.g., cargo boxes, canoes, etc.) increase aerodynamic drag and lower FE. Vehicles are not tested with additional cargo on the exterior.
• Do not tow unless absolutely necessary: Towing a trailer or carrying excessive weight decreases fuel economy. Vehicles are assumed to carry three hundred pounds of passengers and cargo in the EPA test cycles.
• Minimize running mechanical and electrical accessories: Running mechanical and electrical accessories (e.g., air conditioner) decreases fuel economy. Operating the air conditioner on "Max" can reduce MPG by roughly 5-30% compared to not using it.
• Avoid driving on hilly or mountainous terrain if possible: Driving hilly or mountainous terrain or on unpaved roads reduces fuel economy most of the time. The EPA test assumes vehicles operate over flat ground.
• Do not use 4-wheel drive if it is not needed. 4-Wheel drive reduces fuel economy. Four-wheel drive vehicles are tested in 2-wheel drive. Engaging all four wheels makes the engine work harder and increases crankcase losses.

[honda03842]

Kevin, those are definitely the basics. There are many pages of more advanced techniques. A very interesting site. Norm

[Mike Magee]

"Do not tow unless absolutely necessary." True enough. But for all of us, it is absolutely necessary! I don't think I could stand not camping with my trailer this summer! lol

[Rarebird]

[QUOTE=Kevin K;253496]

• Do not accelerate quickly or brake heavily: This reduces fuel economy by as much as 33 percent at highway speeds and 5 percent around town. EPA tests do not account for this kind of vigorous driving.
• Do not idle if not necessary: Decreases average FE. The EPA city test includes idling and in many cases, it is not necessary. Consider shutting down your vehicle if stopped for more than 7-seconds as that is all the fuel it takes to restart a modern day, fuel-inject engine.
• Avoid driving at higher speeds: This increases aerodynamic drag (wind resistance) and mechanical friction which reduces fuel economy. The EPA test accounts for aerodynamic drag up to highway speeds of 60 mph, but most exceed that speed far more often then necessary.
• Cold weather and frequent short trips reduce fuel economy, since your engine doesn't operate efficiently until it is warmed up. In colder weather, it takes longer for your engine to warm, and on short trips, your vehicle operates a smaller percentage of time at the desired temperature. Note: Letting your car idle to warm-up does not help your fuel economy, it actually uses more fuel and creates more pollution. Drive to your furthest destination first and then as you are heading home, stop at the closer destinations in order from furthest to closest as the car is warmed up for longer portions of your drive.
• Remove Cargo or cargo racks: Cargo and/or racks on top of your vehicle (e.g., cargo boxes, canoes, etc.) increase aerodynamic drag and lower FE. Vehicles are not tested with additional cargo on the exterior.
• Do not tow unless absolutely necessary: Towing a trailer or carrying excessive weight decreases fuel economy. Vehicles are assumed to carry three hundred pounds of passengers and cargo in the EPA test cycles.
• Minimize running mechanical and electrical accessories: Running mechanical and electrical accessories (e.g., air conditioner) decreases fuel economy. Operating the air conditioner on "Max" can reduce MPG by roughly 5-30% compared to not using it.
• Avoid driving on hilly or mountainous terrain if possible: Driving hilly or mountainous terrain or on unpaved roads reduces fuel economy most of the time. The EPA test assumes vehicles operate over flat ground.
• Do not use 4-wheel drive if it is not needed. 4-Wheel drive reduces fuel economy. Four-wheel drive vehicles are tested in 2-wheel drive. Engaging all four wheels makes the engine work harder and increases crankcase losses.

I have a question regarding the fifth suggestion down on this list. We tow our Trillium 1500 with a Honda Pilot. The trailer is boxy, and taller than the Pilot, so I was thinking it might actually help mileage to put a cargo box, with a sloping front, on the Pilot.
On our longest trip, to Florida from NY, we averaged 15-16 mpg. We don't drive fast, and the trip was flat.
Any aerodynamic experts out there?? Would a "pod" help in this situation?
Marjie

[Mike Magee]

I have read one (or two?) claims of people who put a canoe on their tow vehicle and said it improved their towing fuel economy. But it's hard to be sure if any given rooftop thing will help. I don't think a cargo shell or canoe would hurt, since like you say it has to hit something up there eventually. If you try it, let us know the result.

[Andy B]

Originally Posted by Kevin K

Operating the air conditioner on "Max" can reduce MPG by roughly 5-30% compared to not using it.

30% reduction in MPG for using an air conditioner sounds like a gross over statement.

[honda03842]

Andy,

You're probably right. I suspect that on average it's at the lower end of the range however on an instantaneous mileage basis it probably covers that kind of range though 30% sems high to me as well.
.
If you're running at low speeds in traffic, the number may be significantly higher than 5% since the air conditioning load is relatively constant regardless of speed or MPG.

With UltraGauge I notice in first gear my mpg is around 10 mpg and near 30 mpg on the highway, so highway use of air is a significantly lighter load on a % basis.

Norm

[Andy B]

Originally Posted by honda03842

Andy,

You're probably right. I suspect that on average it's at the lower end of the range however on an instantaneous mileage basis it probably covers that kind of range though 30% sems high to me as well.
.
If you're running at low speeds in traffic, the number may be significantly higher than 5% since the air conditioning load is relatively constant regardless of speed or MPG.

With UltraGauge I notice in first gear my mpg is around 10 mpg and near 30 mpg on the highway, so highway use of air is a significantly lighter load on a % basis.

Norm

I have a ScanGage II and thought I would use it to see if AC or open windows used more gas at highway speed. I could not reliably detect any change at all in MPG turning the AC on and off, or for opening and closing the windows. Very small slope changes in the road would affect mpg and would overwhelm any difference for the AC. I concluded that the AC was not a significant factor in MPG with my 4 cyl Tacoma. A 30% reduction would reduce my 27 mpg down to 19 mpg! Even a 5% reduction would reduce the 27 mpg down to 25.7 mpg and be easily detectable.

[honda03842]

Andy, Nothing beats real world tests. I'll have to try it myself.

Norm

[honda03842]

Andy,
I took my Honda for a spin around our rather flat neighborhood and turned Max Air on and off. As you discovered on your Tacoma, I could not notice any change in fuel usage on my Honda.

Is it possible that we have electric AC and it gets integrated into the battery/generator setup?

Norm

[Mike Magee]

Originally Posted by honda03842

Andy,
I took my Honda for a spin around our rather flat neighborhood and turned Max Air on and off. As you discovered on your Tacoma, I could not notice any change in fuel usage on my Honda.

Is it possible that we have electric AC and it gets integrated into the battery/generator setup?

Norm

If you locate your AC compressor and see if it has a belt pulley driving it or not, you'll know.

[mcbrew]

It doesn't matter whether it is belt or electric, it takes the same amount of power. If it were electric, the alternator would be working harder to supply it with power.

I, too, don't notice much of a difference with the AC on or off. This is especially true with newer cars, which tend to have variable displacement AC compressors. You'll notice in most newer cars that the compressor doesn't "kick in and out" like they used to, but run all the time and vary the displacement to provide just the right amount of compression. This is much more efficient than shutting off and allowing the system pressure to equalize, then turning back on and re-pressurizing the system. My car has real-ytime and overall (tank) fuel economy. I also do the math at every fill up (I use Fuelly.com). I can't tell a difference. Now, then I tow the Scamp, there is a BIG difference!

[Roger C H]

I never tried to compare mileage with and without the air conditioner. However, I will say I can feel the drag of the A/C on the engine when I turn it on.

As far as wind deflectors, there are several available. I talked to a fellow who used one on his 5th wheel. He claimed it improved his mileage.

RV Towing Products - Wind Deflectors - IconDirect

I would like to mount one of these on my rig.

[honda03842]

We've had our's for a couple of months. Since our toad is seven years old, it does not provide mpg information. I believe the gauge has changed our driving habits.

We took a 300 mile trip to CT from NH this weekend, mostly Interstate, not towing. Normally we average 28 mpg in our Honda CRV on the Interstate, sometimes 30. On this trip we averaged 33 mpg for 300 miles.

Obviously we won't get rich doing this but it has other benefits as well. Before we were heading off to Prince Edward Island it flashed a warning that cylinder 1 had not fired, not enough to post a permanent code, but rather a warning code. It happened a few times over the week.

As a result we changed the spark plugs, they did have 145,000 miles on them.

Not a bad $60 investment.

Norm

[cpaharley2008]

There was an episode on "Mythbusters" where the difference between a/c and open windows was negligible.
I remember something my father told me when learning to drive, drive as if you have an egg between your foot and the gas pedal. It is good advice to good mpg.

[honda03842]

You may be correct about open windows versus closed windows but I think air conditioning versus no air conditioning is another matter. One of the gauges I watch is percentage of engine capacity and turning the air on instantly increases percentage of capacity used.

On our trip we did have air on the way down.

Norm