Cyclist Calculates “MPG” on a bike!
In 2005 Nick Goddard was working at a car magazine and was assigned to write an article on a flex-fuel car that could run only on ethanol. Goddard learned a lot about how much energy is in a gallon of gas and being a science minded guy, he started to wonder how far he could ride his bike on the equivalent of the energy in a gallon of gasoline. Read on to learn the results of what became a coastline trip by bike!
How many miles per gallon does a bicycle get?
By Nicholas Goddard
While working at a car magazine two years ago, I was assigned to write an article on a flex-fuel car that could run on ethanol. Early into my research, I learned that there is actually less energy in a gallon of ethanol than there is in a gallon of gasoline. I started wondering just how much energy was in the 11 gallons of gas I had burned up driving a Corvette Z06 the previous night. It felt like a lot—the car had spun its tires, was inappropriately fast and screaming loud, and mirages poured from the wheel wells at each stoplight. But was there a way to compare that fuel consumption with something besides other cars? How far, for instance, could I ride my bike on the energy in a gallon of gas?
A few clicks later, I found out that there are 31,000 Calories in every gallon of gasoline (That’s the same Calorie that weightlifters flock to and dieters avoid—A Calorie is just a unit of energy equal to the amount of energy needed to heat a Liter of water by 1 degree Celsius). That’s as much energy as is in two weeks of food, and though I wasn’t planning to drink gasoline, a quick calculation led me to believe that I would be able to ride between 500 and 1000 miles on that 31,000 calories.
I had a vacation during the summer so it was a perfect time to test the idea. I armed myself with a Calorie-measuring heart-rate monitor and a cyclocomputer and prepared a 1970’s Austro-Daimler from my parents’ basement. All that was left was to decide on a route—I chose to start in Connecticut and headed south.
Since my first multi-speed bike, I had ridden mountain bikes—riding my same local trails over and over again—so when I pedaled the Austro-Daimler onto Route 1 out of New Haven, CT at the beginning of my ride, it shocked me with its speed, how—even with 20 pounds of gear strapped to the rack on the back—it carried speed better than my mountain bike ever had. I rose to the occasion, powering out of the saddle over crests just to keep the tires humming.
The soothing speed was welcome, as the remainder of the first day forecast a high rate of incidents for the rest of the trip; In Stamford, I crashed into a Lexus that turned across my path as I fumbled with my camera, and my spandex attracted stares from the entire staff of a White Castle in the Bronx while I asked the cashier for directions to Manhattan. I soon rocketed past two miles of stop-and-go traffic on a section of I-95 after misinterpreting those directions. Ironically, that stretch was the fastest and most relaxing part of the day’s ride, but the police who demanded I leave the highway were not so amused. The first day ended with a few miles in Central Park, where I could finally blend in with the packs of spandex-clad roadies who traced the perimeter.
Day 1: 4,458 Calories, 75.2 miles à 522 “miles per gallon”
With a heart-rate monitor measuring my Caloric expenditure, I didn’t need to keep track of my food consumption. Nevertheless, my relationship with food had changed by the third day. Rather than balancing taste and healthiness, I began to think of every morsel as fuel, and slowly my purchases became motivated by “calories per dollar”—the more carbs, fat and oil the better (vegetable and olive oils have about 30,000 Calories per gallon—very close to gasoline). Even so, I splurged that morning on a pre-ride snack, buying a coffee and blueberry muffin from a local café before heading off to Baltimore via a MapQuest-provided route.
I taped the directions to my handlebar and headed to the nearest bakery, where I purchased a huge, calorie-rich and day-old loaf of wheat bread for just $2. I figured that food without much flavor would taste better late in the day, but for now I was running just fine on blueberry burps.
Five miles into the day I reached the end of a bridge, which put me 25 miles from Pulaski Highway, on which I would travel the remaining 60 miles to Baltimore. Pulaski has a whole lane dedicated to bikes, but is otherwise like any other suburban highway in the US; arrow-straight and peppered with strip malls and car dealerships. I would have to ride into the wind for the rest of the day, against hundreds of American flags blowing toward me. I was hungry too, and the small amount of wheat bread I had left wasn’t going to be enough—I treated myself to an Italian sub from Roma Pizza in Bear, Delaware. Piled high with meat and slathered with oil and mayonnaise, it tasted like heaven.
Day 5: 15158 Calories, 281.1 miles à 574 “miles per gallon”
The eighth day took me from Durham to Chapel Hill, NC—a ride of less than ten miles. However, I felt huge excitement as I burned the 31,000th Calorie, in the college town of Chapel Hill, North Carolina. I had an actual figure now—633 “miles per gallon.” The bike seemed so light, so efficient compared to the conveyor-belt of automobile traffic that had grumbled alongside me the entire ride.
Day 8: 31000 Calories, 633 miles à 633 “miles per gallon”
After 600+ miles by bike, the Greyhound bus I took back to New Haven was unfathomably rapid; there was no wind, just still, dry air, and the idle chitchat of the other passengers. It didn’t matter if my eyes were open or closed—even if I slept, the scenery still rushed by. I was free to look at my radio when I changed the station, and I could even go to the bathroom while on the move. The three layovers afforded me a nice chance to stretch out, but I just couldn’t get a feel for any of the country we covered.
Looking back, the magic hour of the bike trip was the final stretch of the ride from New York to Philadelphia—getting lost in Newark had added hours to the day and there was no chance of arriving before 11 PM. I gave up caring about the diminishing daylight and found an unlit country road. With 80 miles down and 20 to go, I blasted music in the dark for an hour of spirited riding, and slid silently through the night in what amounted to complete darkness. Pounding up hills out of the saddle, I was Eddie Merckx and Tinker Juarez, and felt like my legs would never fade. Now, even in the city, every trip I take on my bike is like a tiny flashback to those extended moments of glory on the trip. It was when I couldn’t see the Calories, couldn’t see the speed, couldn’t even see the road that I enjoyed riding the most. With music crackling through my armband radio, legs and body glowing with the warmth of a 2-day sunburn and 150 miles of riding, it was a totally new experience. What counts is being on a bike—even when you don’t record the numbers, the earth does and loves you for it.
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Chris Says:
I just want to know how you can say that? Don’t get me wrong. I love riding, but while driving a car you don’t have to stop every couple of hours to replenish the car. So, in essence you are replenishing your caloric intake everytime you eat. Most cars get about 300 miles to a tank. Ride your 633 miles without eating and see what happens. You won’t make it. If it sounds like I am being negative, I’m not. I just don’t see how you can say 633 miles per calorie, when you keep eating. Help me with this?
Rebecca Says:
Nick! Thanks for making the ride. I’m hoping to burn a few mpg on my bike this weekend; it’s supposed to be in the 30s!
will barley Says:
Rock on Nick. That’s an awesome idea and it sounds like a cool trip.
Randy Says:
Chris…
If Nick could eat 31,000 calories and store them for the duration of his ride, then that would be similar to your car analogy. But the body cannot store that many calories at once (although many people have fat reserves equal to that amount of calories). So, the math is pretty straight forward, with the two variables being his calories burned per hour on the bike and his speed. Assume he is averaging 14mph and burning 650 calories per hour. He has 31,000 calories to use…so 31,000/650 = 47.69 hours of ride time x 14 miles per hour equals 667.66. In the ballpark of what Nick calculated.
Other Fuel Oils Says:
Recycled Cooking Oil for Inexpensive Diesel Auto Fuel…
Thirteen years ago, when we owned a health food store, an old beat up VW Rabbit, parked in front of our store, and I noticed it had signs and writing on the windows. It said, “This vehicle runs on used vegetable oil”. The gentleman came into the stor…
Mork Says:
Chris.
Fuel economy is not dependant on the size of your gas tank….
Eric Says:
Eric…
Love the blog. Ive dugg you in my digg account for future reading!…
Michael Says:
Awesome post. While it’s true you can’t compare miles per “tank” to what the human body can store and use in a single journey. It’s also not practical to compare the total distance you can travel by car on a single tank of gas without taking into consideration the number of stops required for bathroom breaks. Most people probably couldn’t hold out for more than 200-300 miles without a rest stop…even less if you have kids in the car! :)
You’ve been Stumbled!
Sue Says:
Calories are Calories. If the calories came from gasoline, then X calories would require Y gallons. (31,000 calories would require 1 gallon.) That’s the premise here.
Of course, it doesn’t factor in the production costs of the food; we’re not grazing along the road as we ride. If those Calories came from individually wrapped Gu then the relative efficiency is rather arguable.
Sue Says:
(Of course, we’re also not considering the production costs of the *gasoline.*)
Gary Says:
Nick
Well done and a valuable comparison to make. One thing I would mention that increases computed mpg for the cyclist - the human body requires a baseline of energy just to operate. The calories associated with that baseline functionality (I’ve heard numbers like 1000+ calories per day) should not be included in the calculation since they are baseline calories used whether the cyclist is cycling or sleeping or whatever…… Assuming that your fuel consumption was over-stated by about this amount suggests that calculated mpg is really about 1/3 higher (around 850 miles per gallon equivalent). Not bad!
Gary
Charlie Says:
Awesome ride Nick! Excellent idea!
We could also look at this in terms of cost:
31,000 calories = 1 gallon of gasoline = $3.00
31,000 calories = A BigXtra w/cheese, Lg French Fries, and an Oreo McFlurry (all ordered 16 times). = $160.00 *assuming $10/order
Toyota Prius (48mpg): 633m/48mpg = 13.1875g *$3 = $39.57
Ford F150 (12mpg): 633m/12mpg = 52.75g * $3 = $158.25
Cyclist (633mpg): 633m/633mpg = 1.0g * $160per g = $160.00
The price per gallon for the cyclist is substantially high but so is the consumption of the 12mpg F150. The Prius however, might have the cyclist beat in terms of travel cost, but it’s lead quickly diminishes when you include the vehicles price, tax, title, license, insurance, parking, traffic violations and maintenance or if you eat food that is less expensive then McDonald’s.
Gabriel Says:
Awesome article!
Other things to consider. Over time (weeks and months) or riding regularly, your body becomes more efficient at converting caloies to distance, i.e. your mileage actually improves!
Sue, regarding your comment about where the calories came from, production costs, etc. it’s a valid point. I would reply by pointing out that in a car you have no choice, they have to come from crude oil and exit your tailpipe as co2, nitrous oxides, etc. whereas on the bike you have a broad range of foods and food sources to choose from.
Nick, I hope you keep up the riding. I discovered the joys of human propulsion many years ago and ride to/from work over 55 miles a day. There’s a whole bunch of resources online, just google “car free” or check out www.bikeforums.net
Greg Says:
Cool article, I’ve always wondered the MPG for a cyclist were. thanks.
Mike 2 Says:
For those that may think driving that same distance in a car is cheaper than riding a bike, think about this. Your body needs food whether or not your riding. You will still make pit stops and eat food along with purchasing gas. So you should probably halve his food bill and then tack it on to your vehicles gas bill. Then you’ll know that the cycling was probably cheaper. Unless your fasting for whatever holiday it is. To cheaper and healthier cycling! Ride On!
Weighty Thoughts Says:
Of course, the engine in most cars alone weights more than a bike and its rider. I wonder what MPG a biker would get if he/she were peddling a ton and a half car…Or if we put an internal combustion engine on a bike…Oh wait…They’ve done that…
Because a calorie is a calorie, and a pound is a pound, we should be comparing loads of equal weights as well. Then we can see if the human is more efficient than the Honda.
Also, someone mentioned the production and delivery costs of the food. What about production and delivery of gasoline? I’m pretty sure we can consider them equal for sake of argument.
Also, with added respiration and metabolism, the human body increases its output of CO2. So we should compare how much CO2 the body produces at rest, and in motion (relative to the weight of an average automobile). And we could find out if cycling is better or worse for greenhouse gases. Wouldn’t that be ironic?
nickjohnson Says:
I’m not surprised!
According to world watch (http://www.worldwatch.org/node/4057), driving a car takes 1,860 [kilo]calories per passenger-mile; walking takes 100 [kilo]calories per passenger-mile; cycling a mile takes 35 [kilo]calories per passenger-mile (energy in, change in position of a mass out). If we ignore everything except the effect–moving one passenger one mile–we can estimate the relative efficiencies: a car is less than 1/50 as efficient, and walking is about 1/3 as efficient as riding a bike.
Thanks for the article!
Mountain Bike Insurance Says:
Mountain Bike Insurance…
I couldn’t understand some parts of this article, but I guess I just need to check some more resources regarding this, because it sounds interesting….
Aaron Says:
Nick;
This is a wonderful article and it sounds as if you’ve really discovered the measurable and non-measurable benefits of traveling by bike. Interestingly I had read some time ago that a bicycle is measured as having the equivalent to 1500mpg in the lab (though I can’t find the study right now).
Many valid points have been made here including the choice of fuels and the power/weight ratio of a bike.
I would also like to respond to Chris. As a teenager I was sometimes in the position of having an empty wallet. One day I was coming home from a bike ride and I had eaten all my food. However despite having an ‘empty gas tank’ I was still able to pedal my bike home and eat a huge meal. I don’t think that any automobile (no matter what fuel source) would be able to get you home on an empty tank.
Casey Says:
Randy,
Don’t give the kid a hard time. How much time do you spend in your car making 300 mile drives? Thats what I thought. The majority of Americans commute less than 40 miles a day. I live in California where the price of gas is close to $4/gallon. I estimate that I save $24/week on fuel. I am healthier and I feel great when I get to work.
Casey
Nick Goddard Says:
Hey guys—thanks for all the great responses! In case anyone is wondering, the point of this ride wasn’t to show that riding a bike is better for the environment than driving a car (it probably depends what you eat, and what you fuel the car with), or that it is less expensive. Rather, I had just wondered if my bike was using energy so effectively as I thought—road bikes really glide along the pavement, you barely need to pedal them, they don’t seem to use any food or gas (though of course they do) and they are stay ice cold even after you ride them really hard (suspension systems and brake systems excluded–everything else probably warms up hundredths or tenths of degrees).
Contrast an ice cold bike to a car. Each car controls literally thousands of explosions under the hood every minute and burn hundreds of Calories when you floor it (maybe 750 Calories in an average car if you floor it for a quarter mile). The brakes get wildly hot, and the dampers get so hot you can’t touch them. Cars can stay hot for an hour or two after you drive them.
I just wanted to know how the energy usage of a rumbling car compared to the my lovely gliding road bike. Don’t get me wrong, I love cars, but the more I ride, the more I see the merits of riding, both for me, and for citizens of our country.
@ Sue: Yup! (although we’re talking kilocalories, or “Calories” with a capital “C” here—they’re the same Calories that you are used to eating—100 Calories in a slice of bread, for example.
And you’re right the production costs of food can vary—you could eat lettuce air-freighted from across the world, or toss a few seeds in your back yard and eventually pick the apples that spring up—for free. I don’t really have a good idea how much the costs for supermarket food is. I suspect the production costs of certain foods vary dramatically from season to season.
@ Gary– Thanks! You’re absolutely right- people do indeed have a “maintenance energy expenditure”—it is called the “Basal Metabolic Rate” and it is the energy you use, basically, to stay alive. You can think of it as the number of Calories you’d burn per hour if you were sitting still in the dark.
The heart rate monitor I used (a Polar F11) was measuring energy expenditure above my BMR; unless my heart rate rose above my “resting heart rate,” my HRM recorded my instantaneous energy expenditure at 0 Calories / hour.
So you’d think that the eventual result of the experiment, “633 mpg,” would be a good number to compare to a car’s “miles per gallon.” However, I’ve read on various forums that Polar’s heart rate monitors overestimate Caloric consumption by as much as 50%, which would mean that my actual efficiency may have been as much as 945 mpg.
At steady state, a car’s main enemy is drag, not weight; so additional passengers are relatively “inexpensive.” If a suburban is getting 12 mpg and you fill it with 6 more people, it is still going to get nearly 12 miles per gallon (say 11 for the sake of argument). That means it gets 12 “passenger miles per gallon” one-up, but 77 “passenger miles per gallon seven-up—just something to think about. One person driving a 40 mpg Prius isn’t that efficient (although four-up a prius gets 160 “passenger miles per gallon”). A Greyhound bus gets 4 mpg, but if you stuff 40 people in it, you’re getting 160 “passenger miles per gallon”. Assume a little kid in a child-seat does little to affect the efficiency of a cyclist and that bicycle will be knocking on the door of 1300 “passenger miles per gallon”
@ Gabriel—wow, that’s a long commute- I bet you’re in great shape!
@ Mountain Bike Insurance –wow your name is Mountain Bike Insurance?