{"id":2272,"date":"2008-01-05T23:14:37","date_gmt":"2008-01-06T04:14:37","guid":{"rendered":"http:\/\/www.brianarner.com\/weblog\/wordpress\/2008\/01\/how_many_miles\/"},"modified":"2008-01-05T23:14:37","modified_gmt":"2008-01-06T04:14:37","slug":"how_many_miles","status":"publish","type":"post","link":"http:\/\/www.brianarner.com\/weblog\/2008\/01\/how_many_miles\/","title":{"rendered":"How Many Miles Per Gallon Of Gasoline Could I Travel On My Bicycle?"},"content":{"rendered":"

With oil prices at $100 per barrel, people are concerned about the “high” cost of gasoline. That’s understandable, because a typical household with two commuters can shell out a lot at the gas pump.
\nBut viewed comparatively, as Matthew Simmons<\/a> often notes, gasoline is relatively cheap. At $3\/gallon, gas costs less than 20 cents per cup. That’s less than coffee, milk, or even bottled water. And you can certainly do a lot more work with a cup of gas than with a cup of milk.
\nThe problem is that we burn a lot of it. Motor vehicles are a rather wasteful means of transportation. First, the internal combustion engine is only about 20% efficient<\/a> in converting energy into work. Second, drivers typically move thousands of pounds of extra (unnecessary) weight with them as they go. Think about it–in many (most?) cases when you get in a car or truck, you simply want to get yourself from point A to point B. And yet the vehicle requires you to haul all that metal with you.
\nImagine you could harness the energy from gasoline into what may be the most efficient of vehicles: the bicycle. Suppose you could drink gas and convert its energy into work. How many miles could you travel per gallon?
\nA quick Internet search offers some widely-varying estimates. This Wikipedia entry<\/a> says 653 miles per gallon. But this site<\/a> says 912 miles per gallon. That’s quite a discrepancy–one I assume is largely due to the assumptions on riding style used in the estimate. The energy required to travel on a bike varies according to how fast you are going (wind resistance) and the type of tires you have (rolling resistance).
\nFor the heck of it, I’m going to calculate how far I could go on a gallon, based on typical riding characteristics. [Warning: I’m not a science guy, so this exercise is fraught with mathematical peril.]
\nFirst, I must determine how much energy a gallon of gas contains.
\nOne U.S. gallon of automotive gasoline = 125,000 BTU\/gallon<\/a>
\nOne BTU = 1055 joules<\/a>
\nSo one gallon (125,000 x 1,055 ) = 131,881,987 joules (per this converter<\/a>).
\nNext, I determine how much work that energy can perform.
\nAccording to some experiments, the human body is 25% efficient<\/a> in converting ingested fuel into useful mechanical energy.
\nSo I could theoretically get (0.25 x 131,881,987) = 32,970,497 joules from the gas.
\n1 joule = 1 watt-second<\/a>
\nThus 32,970,497 joules = 32,970,497 watt-seconds
\nHow much power do I consume while riding? This site<\/a> lets you calculate it based upon your ride characteristics. Mine are as follows:
\nRacing bicycle with hands on top of the bars
\nRider’s Height \t70 in
\nRider’s Weight 160 lb
\nBicycle Weight 21 lb
\nAir Temperature 65 F
\nHeight above Sea Level 980 ft
\nSlope of Road 1.5%
\nWind Speed 3 mph
\nPedaling Cadence 80\/min
\nNarrow, high-pressure racing tires
\nSpeed: 18.0 mph
\nWith the above data the calculator indicates that under “typical” riding conditions, I need 330 watts of power.
\nThus, 32,970,497 watt-seconds \/ 330 watts per second = 99911 seconds
\n99911 seconds \/ 3600 seconds per hour = 27.75 hours of riding
\n27.75 hours x 18 mph = 499.5 miles
\nSo I estimate that if I could consume gasoline, a gallon of the fuel would allow me to ride 499.5 miles<\/strong>, given my typical riding.
\nThat would be much easier on the wallet, as it’s farther than I can go with an entire tank of gas in my Honda.
\nIf I wanted to get even more bang for my buck, I could simply ride slower. If I reduce my speed in the above equation to from 18 mph to 13.8 mph, I could ride 632 miles.<\/p>\n","protected":false},"excerpt":{"rendered":"

With oil prices at $100 per barrel, people are concerned about the “high” cost of gasoline. That’s understandable, because a typical household with two commuters can shell out a lot at the gas pump. But viewed comparatively, as Matthew Simmons often notes, gasoline is relatively cheap. At $3\/gallon, gas costs less than 20 cents per […]<\/p>\n<\/a>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-2272","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-uncategorized","7":"h-entry","8":"hentry"},"_links":{"self":[{"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/posts\/2272","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/comments?post=2272"}],"version-history":[{"count":0,"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/posts\/2272\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/media?parent=2272"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/categories?post=2272"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.brianarner.com\/weblog\/wp-json\/wp\/v2\/tags?post=2272"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}