{"id":1095,"date":"2010-05-22T15:37:26","date_gmt":"2010-05-22T19:37:26","guid":{"rendered":"http:\/\/www.motorcycle-journeys.com\/blog\/?p=1095"},"modified":"2010-05-22T15:37:26","modified_gmt":"2010-05-22T19:37:26","slug":"confused-by-mpg","status":"publish","type":"post","link":"https:\/\/www.motorcycle-journeys.com\/blog\/confused-by-mpg\/","title":{"rendered":"Confused by MPG"},"content":{"rendered":"

Maybe someone can explain this. Do combustion engines burn less fuel at altitude?<\/p>\n

I normally plan on getting gas at around 150 miles on the tank or when the fuel light comes on. I don’t have a fuel gauge, just a 4.2 gallon tank and a fuel light that is supposed to come on when there is a gallon left in the tank. I feel the fuel light it very accurate since I have many times put 3.2 gallons in when the fuel light had just come on.<\/p>\n

I was heavily loaded for this trip and this is the first really long trip I’ve taken since I changed from a 47 to 49 tooth rear sprocket that changed the gearing ratio of my motorcycle and effectively dropped my miles per gallon by about 5. I am okay with the drop in mileage because the motorcycle no longer bogs and hesitates at really slow speeds — something I was never comfortable with.<\/p>\n

While I was at high elevation on Wednesday cutting across Colorado I got bizarrely good mileage. Granted I went slow for the 50 miles I was in a snow storm, but that still doesn’t explain what happened. I was riding through Denver with around 200 miles on the tank and still no fuel light. I was beginning to worry the fuel light had gone out. It just came on as I was getting off the highway to fuel up and this is backed up by the fact I put in 3.222 gallons at the fuel stop. What doesn’t make sense is the fuel light coming on at 224.5 miles and getting almost 70 MPG on that tank of fuel.<\/p>\n

It should be noted that I normally burn regular gas in my motorcycle, but while in other states I realized the regular grade dropped to 84, 85, and 86 octane. My motorcycle wants minimum of 87 so I bumped to mid-grade fuel in those states. I noticed the drop in octane in Nevada, Utah, and Colorado. Texas has 87 octane for regular and I’m not sure about New Mexico, Arizona, and California. I don’t think I noticed the drop until Nevada where it was 84 (???).<\/p>\n

Below are the details of my gas purchases and MPG. There definitely seems to be a trend to high MPG when I was at altitude most of the day, just as there was a trend to low mileage when fighting head winds at the start of the trip. The other anomaly was the 46 MPG from Quanah, Texas to Decatur, Texas when I was consistently riding at 75-77 MPH in light winds just like the day before.<\/p>\n

If anyone has an ideas on what explains this I would love to hear because I don’t get it. And I’d like to do whatever I can to maximize my MPG.<\/p>\n\n<\/col>\n<\/col>\n<\/col>\n<\/col>\n<\/col>\n<\/col>\n<\/col>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Date<\/td>\nPlace<\/td>\nAmt<\/td>\nMiles<\/td>\nGallons<\/td>\nMPG<\/td>\nComment<\/td>\n<\/tr>\n
5\/10\/2010<\/td>\nEXXONMOBIL 46914404 WICHITA FALLS TX<\/td>\n6.20<\/td>\n119.0<\/td>\n2.295<\/td>\n51.9<\/td>\n<\/td>\n<\/tr>\n
5\/11\/2010<\/td>\nSHELL OIL 574409479QPS CLARENDON TX<\/td>\n10.98<\/td>\n172.0<\/td>\n3.839<\/td>\n44.8<\/td>\n<\/td>\n<\/tr>\n
5\/11\/2010<\/td>\nLOVE S COUNTRY00002626 TUCUMCARI NM<\/td>\n10.03<\/td>\n173.6<\/td>\n3.533<\/td>\n49.1<\/td>\n<\/td>\n<\/tr>\n
5\/11\/2010<\/td>\nFlying J C store outsi Alburquerque NM<\/td>\n11.27<\/td>\n189.0<\/td>\n4.115<\/td>\n45.9<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/12\/2010<\/td>\nSHELL OIL 57443907001 GALLUP NM<\/td>\n8.86<\/td>\n144.5<\/td>\n2.936<\/td>\n49.2<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/12\/2010<\/td>\nSHELL OIL 574400399QPS SELIGMAN AZ<\/td>\n12.18<\/td>\n137.2<\/td>\n2.851<\/td>\n48.1<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/12\/2010<\/td>\nFlying J C store outsi Winslow AZ<\/td>\n9.71<\/td>\n136.0<\/td>\n3.374<\/td>\n40.3<\/td>\nleft cap open<\/td>\n<\/tr>\n
5\/12\/2010<\/td>\nCHICAGO DELI AND BAR 7024985431 NV<\/td>\n9.05<\/td>\n172.8<\/td>\n3.059<\/td>\n56.5<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/13\/2010<\/td>\nSHELL OIL 574423431QPS PAHRUMP NV<\/td>\n6.47<\/td>\n117.0<\/td>\n2.086<\/td>\n56.1<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/13\/2010<\/td>\nSIERRA GATEWAY SPORT LAKE ISABELLA CA<\/td>\n9.22<\/td>\n194.8<\/td>\n2.883<\/td>\n67.6<\/td>\n<\/td>\n<\/tr>\n
5\/13\/2010<\/td>\nSTOVEPIPE GAS DEATH VALLEY CA<\/td>\n7.80<\/td>\n131.4<\/td>\n2.209<\/td>\n59.5<\/td>\n<\/td>\n<\/tr>\n
5\/13\/2010<\/td>\nTable Mountain Chevron Madera, CA<\/td>\n11.93<\/td>\n179.7<\/td>\n3.103<\/td>\n57.9<\/td>\naverage 80 mph<\/td>\n<\/tr>\n
5\/16\/2010<\/td>\nChevron Jamestown, CA<\/td>\n11.44<\/td>\n207.4<\/td>\n3.219<\/td>\n64.4<\/td>\nyosemite<\/td>\n<\/tr>\n
5\/16\/2010<\/td>\n7-Eleven Carson City, NV<\/td>\n7.25<\/td>\n167.3<\/td>\n2.450<\/td>\n68.3<\/td>\n<\/td>\n<\/tr>\n
5\/17\/2010<\/td>\nFox Peak Station Fallon, NV<\/td>\n2.72<\/td>\n63.2<\/td>\n0.926<\/td>\n68.3<\/td>\n<\/td>\n<\/tr>\n
5\/17\/2010<\/td>\nCHEVRON 0093193 Q61 AUSTIN NV<\/td>\n6.12<\/td>\n113.2<\/td>\n1.922<\/td>\n58.9<\/td>\n<\/td>\n<\/tr>\n
5\/17\/2010<\/td>\nSHELL OIL 527264000QPS ELY NV<\/td>\n14.44<\/td>\n156.2<\/td>\n2.642<\/td>\n59.1<\/td>\n<\/td>\n<\/tr>\n
5\/17\/2010<\/td>\nBORDER INN 00397489 GARRISON UT<\/td>\n6.93<\/td>\n126.3<\/td>\n1.946<\/td>\n64.9<\/td>\n<\/td>\n<\/tr>\n
5\/19\/2010<\/td>\nTEXACO 0306112 BEAVER UT<\/td>\n11.74<\/td>\n187.2<\/td>\n3.308<\/td>\n56.6<\/td>\n<\/td>\n<\/tr>\n
5\/19\/2010<\/td>\nChevron, UT<\/td>\n11.54<\/td>\n187.4<\/td>\n3.405<\/td>\n55.0<\/td>\n<\/td>\n<\/tr>\n
5\/19\/2010<\/td>\nShell Parachute, CO<\/td>\n8.16<\/td>\n151.6<\/td>\n2.632<\/td>\n57.6<\/td>\n<\/td>\n<\/tr>\n
5\/19\/2010<\/td>\nK&G PETROLE53110042422 CASTLE ROCK CO<\/td>\n9.08<\/td>\n224.5<\/td>\n3.222<\/td>\n69.7<\/td>\nvail pass<\/td>\n<\/tr>\n
5\/20\/2010<\/td>\nChevron Raton, NM<\/td>\n10.91<\/td>\n205.0<\/td>\n3.497<\/td>\n58.6<\/td>\naverage 75 mph<\/td>\n<\/tr>\n
5\/20\/2010<\/td>\nExpress Lane Dumas, TX<\/td>\n8.62<\/td>\n172.4<\/td>\n2.972<\/td>\n58.0<\/td>\naverage 75 mph<\/td>\n<\/tr>\n
5\/21\/2010<\/td>\nTaylor Quanah, TX<\/td>\n11.12<\/td>\n197.5<\/td>\n3.835<\/td>\n51.5<\/td>\naverage 75 mph<\/td>\n<\/tr>\n
5\/21\/2010<\/td>\nJ&J Truck stop 380 Decatur, TX<\/td>\n10.57<\/td>\n185.9<\/td>\n4.020<\/td>\n46.2<\/td>\naverage 75 mph<\/td>\n<\/tr>\n
<\/td>\nTotals<\/td>\n244.34<\/td>\n4,212.1<\/td>\n76.3<\/td>\n55.22<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Maybe someone can explain this. Do combustion engines burn less fuel at altitude? I normally plan on getting gas at around 150 miles on the tank or when the fuel light comes on. I don’t have a fuel gauge, just a 4.2 gallon tank and a fuel light that is supposed to come on when […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[63],"tags":[66],"class_list":["post-1095","post","type-post","status-publish","format-standard","hentry","category-general","tag-motorcycle-question"],"_links":{"self":[{"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/posts\/1095","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/comments?post=1095"}],"version-history":[{"count":3,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/posts\/1095\/revisions"}],"predecessor-version":[{"id":1098,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/posts\/1095\/revisions\/1098"}],"wp:attachment":[{"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/media?parent=1095"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/categories?post=1095"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.motorcycle-journeys.com\/blog\/wp-json\/wp\/v2\/tags?post=1095"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}