# Gas mileage

**URL:** <https://community.cartalk.com/t/gas-mileage/54342>\
**Category:** Power/Fuel\
**Tags:** dakota, dodge, fuel-economy, gasoline\
**Created:** [August 29, 2010, 5:48pm UTC](https://community.cartalk.com/t/gas-mileage/54342 "2010-08-29T17:48:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ricksanch](https://avatars.discourse-cdn.com/v4/letter/r/c37758/32.png) [@ricksanch](https://community.cartalk.com/u/ricksanch)\
**Post date:** [August 29, 2010, 5:48pm UTC](https://community.cartalk.com/t/gas-mileage/54342/1 "2010-08-29T17:48:07Z")

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My primary vehicle is a 2005 Dakota. I use 3 primary gas stations in  
  
 Parker, Colorado. I keep close records on gas mileage. I decided thru this summer to mix the stations I use to 3 each over 3 months. I found significant differences in gas mileage, up to 10% to 15%. At station #1 mileage is 18.2 MPG, station #2 16.8 MPG, and Station #3 16.0 MPG. Station #1 is always greater than the others. I suspect the difference is either the lower heat content in enthanol fuel or poor measurement. What do you think?

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**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\
**Post date:** [August 29, 2010, 5:59pm UTC](https://community.cartalk.com/t/gas-mileage/54342/2 "2010-08-29T17:59:53Z")

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MTBE was banned in CO in 2002. Any other chemical that raises the octane rating should be allowed. TAME, ETBE or ethanol are usually the only ones used. Check the 3 stations to see if they all use ethanol and how much is used. Differing levels of ethanol or the use of ETBE could account for the difference in mileage.

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**Author:** ![buggsy2](https://avatars.discourse-cdn.com/v4/letter/b/b5a626/32.png) [@buggsy2](https://community.cartalk.com/u/buggsy2)\
**Post date:** [August 29, 2010, 6:02pm UTC](https://community.cartalk.com/t/gas-mileage/54342/3 "2010-08-29T18:02:12Z")

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Seems a reasonable explanation. How many measurements (tank fills) did you do at each station? That info is needed to establish a standard deviation and thus a significance level.