Ptero
03-10-2008, 03:30 PM
I love the way this forum is set up and I've seen some good folks from other related forums posting here about hypermiling so I thought I'd throw in my 2-cents.
I started hypermiling as an impoverished high school student back in 1968 when gas was 25-cents a gallon. This is where I learned to pulse and coast my '41 Chevy coupe and slide around turns without braking. I used to do dirty motorcycle trips on my belly with my feet hooked over the taillight to reduce drag. My best mileage was a trip from Bakersfield to San Francisco where I also drained every hose at every gas station on Hy 99! (Does that qualify as hypermiling? If not, neither do attempts by my friends using resturant-filtered biodiesel.)
In the 1980s I was a dedicated cross country hang glider pilot. This required gas to get to the launch point and gas to return home. This was always spl;it between several pilots. But I was such a loner that I would carry straps and hitchhike home with my glider. In terms of passenger miles, I did rather well.
This brings up a few points that I have not seen seriously discussed on this board that relate to FAI competition rules for aviation distance records. One requires that you launch and land at the same elevation. It doesn't matter how far you fly. Otherwise a distance penalty based on your L/D (lift to drag ratio) is deducted from your total claimed distance to account for the potential energy you gained by the altitude difference. This applies directly to accurate hypermiling claims.
Another relevant point is hypermiling for passenger miles or weight miles. Passenger miles are usually ignored by the public. For example, the Hummer is often ridiculed for being a gas hog. While this is true, a Hummer can also achieve the same fuel economy as an econobox. I ran into a poor fellow last year who was on vacation with his family of seven. He told me that people were constantly giving them the finger, and someone even spat on the car! But if you do the math
8 MPG x 7 PASSENGERS = 56 MPG
If someone wants to say that the kids wouldn't be able to drive and therefore should be counted as cargo, I'm willing to fudge and add up their ages to the point where 18 produces another driver. Even with that, the Hummer is getting better than 30 PASSENGER MPG. Most people can't beat that. But loaded buses and some RVs can do it without trying. Look at the bus
5 MPG @ 70 MPG x 35 PASSENGERS = 175 PASSENGER MPG
And passenger trains? Way over 1000 PASSENGER MPG easily.
I have a big old 40-foot RV, one of the early aluminum frame luxury jobs with the relatively inefficient Cat V8. I was driving it regularly between Albuquerque, NM and Bakersfield, CA (1000 miles) with family when my kid was in college. I would wait patiently at a truck stop until a speed-regulated box semi truck, or better yet a herd of the critters, pulled out, then I would follow at two seconds closing distance for hundreds of miles, often achieving close to 11 MPG. With 3 of us in the RV, that worked out to 33 PASSENGER MPG.
Weight miles are kind of fun. Trains (and ships), again, achieve the best weight per mile. But trucks are also pretty amazing. I used to drive 9-axle super-trains and tank trucks up to 105 feet long, pulling two trailers full of bulk liquids that set me right at a GVW (gross vehicle weight) of 120,000 pounds. Most of you probably haven't seen these as they were only allowed on certain highways in Nevada, Utah, Colorado, Idaho and Oregon. If you scale down the torque-to-weight ratio, you get 1 ft/lb (one pound of force on a 12-inch lever) moving 200 pounds.
120,000 pounds / 600 ft/lb = 200 pounds for each ft/lb
Compare that to a 0.8 liter diesel Smart with a 200 lb driver and full tank
convert Nm to Ft/lbs 110 Nm = 1.356 ft/lb
110 NM @ 2000 rpm / 1.356 = 81 ft/lb
1920 lb / 81 ft/lb = 23.7 pounds for each ft/lb
23.7 ft/lb / 200 ft/lb = 12%
As you can see, the highest-rated econobox is less than one-eighth as power-efficient as
the maximum-loaded highway truck. Another way of looking at it, if you were to scale that truck down to the weight of a Smart CDI, the Smart's diesel would be a 94.8 cc engine!
Then there's CARGO WEIGHT PER MILE but, blissfully, I'll leave that for you to calculate with the suggestion that the numbers will lean heavily in favor of the heavy haulers.
So anyway, there's some of my experience, for what it's worth. My greatest joy is found in racing against myself for better mileage. I try to avoid forcing dangerous closing speeds on others I share the road with, but I believe I have a perfect right to drive at minimum legal speeds when the traffic is sparse. Most of my travel is on rural highways and, to my joy, the one I most frequent is being 4-laned.
I have spent around 100,000 miles driving my turbocharged 5-cyl Volvo 70XC 4WD for economy, using the delightful MPG meter, frequently achieving over 30 MPG. But in February I picked up my Smart ForTwo Pure and I will discuss this experience on the Smart thread.
I started hypermiling as an impoverished high school student back in 1968 when gas was 25-cents a gallon. This is where I learned to pulse and coast my '41 Chevy coupe and slide around turns without braking. I used to do dirty motorcycle trips on my belly with my feet hooked over the taillight to reduce drag. My best mileage was a trip from Bakersfield to San Francisco where I also drained every hose at every gas station on Hy 99! (Does that qualify as hypermiling? If not, neither do attempts by my friends using resturant-filtered biodiesel.)
In the 1980s I was a dedicated cross country hang glider pilot. This required gas to get to the launch point and gas to return home. This was always spl;it between several pilots. But I was such a loner that I would carry straps and hitchhike home with my glider. In terms of passenger miles, I did rather well.
This brings up a few points that I have not seen seriously discussed on this board that relate to FAI competition rules for aviation distance records. One requires that you launch and land at the same elevation. It doesn't matter how far you fly. Otherwise a distance penalty based on your L/D (lift to drag ratio) is deducted from your total claimed distance to account for the potential energy you gained by the altitude difference. This applies directly to accurate hypermiling claims.
Another relevant point is hypermiling for passenger miles or weight miles. Passenger miles are usually ignored by the public. For example, the Hummer is often ridiculed for being a gas hog. While this is true, a Hummer can also achieve the same fuel economy as an econobox. I ran into a poor fellow last year who was on vacation with his family of seven. He told me that people were constantly giving them the finger, and someone even spat on the car! But if you do the math
8 MPG x 7 PASSENGERS = 56 MPG
If someone wants to say that the kids wouldn't be able to drive and therefore should be counted as cargo, I'm willing to fudge and add up their ages to the point where 18 produces another driver. Even with that, the Hummer is getting better than 30 PASSENGER MPG. Most people can't beat that. But loaded buses and some RVs can do it without trying. Look at the bus
5 MPG @ 70 MPG x 35 PASSENGERS = 175 PASSENGER MPG
And passenger trains? Way over 1000 PASSENGER MPG easily.
I have a big old 40-foot RV, one of the early aluminum frame luxury jobs with the relatively inefficient Cat V8. I was driving it regularly between Albuquerque, NM and Bakersfield, CA (1000 miles) with family when my kid was in college. I would wait patiently at a truck stop until a speed-regulated box semi truck, or better yet a herd of the critters, pulled out, then I would follow at two seconds closing distance for hundreds of miles, often achieving close to 11 MPG. With 3 of us in the RV, that worked out to 33 PASSENGER MPG.
Weight miles are kind of fun. Trains (and ships), again, achieve the best weight per mile. But trucks are also pretty amazing. I used to drive 9-axle super-trains and tank trucks up to 105 feet long, pulling two trailers full of bulk liquids that set me right at a GVW (gross vehicle weight) of 120,000 pounds. Most of you probably haven't seen these as they were only allowed on certain highways in Nevada, Utah, Colorado, Idaho and Oregon. If you scale down the torque-to-weight ratio, you get 1 ft/lb (one pound of force on a 12-inch lever) moving 200 pounds.
120,000 pounds / 600 ft/lb = 200 pounds for each ft/lb
Compare that to a 0.8 liter diesel Smart with a 200 lb driver and full tank
convert Nm to Ft/lbs 110 Nm = 1.356 ft/lb
110 NM @ 2000 rpm / 1.356 = 81 ft/lb
1920 lb / 81 ft/lb = 23.7 pounds for each ft/lb
23.7 ft/lb / 200 ft/lb = 12%
As you can see, the highest-rated econobox is less than one-eighth as power-efficient as
the maximum-loaded highway truck. Another way of looking at it, if you were to scale that truck down to the weight of a Smart CDI, the Smart's diesel would be a 94.8 cc engine!
Then there's CARGO WEIGHT PER MILE but, blissfully, I'll leave that for you to calculate with the suggestion that the numbers will lean heavily in favor of the heavy haulers.
So anyway, there's some of my experience, for what it's worth. My greatest joy is found in racing against myself for better mileage. I try to avoid forcing dangerous closing speeds on others I share the road with, but I believe I have a perfect right to drive at minimum legal speeds when the traffic is sparse. Most of my travel is on rural highways and, to my joy, the one I most frequent is being 4-laned.
I have spent around 100,000 miles driving my turbocharged 5-cyl Volvo 70XC 4WD for economy, using the delightful MPG meter, frequently achieving over 30 MPG. But in February I picked up my Smart ForTwo Pure and I will discuss this experience on the Smart thread.