Is it true that some gas stations use higher percent of ethanol in their gas which makes lower mpg isthis true

Question

Is it true that some gas stations use higher percent of ethanol in their gas which makes lower mpg isthis true

Answer 1

Yes, it is true that ethanol blended fuel gives slightly lower miles per gallon that straight gasoline. Gas stations DO NOT add ethanol by themselves. The fuel comes from the refiner or distributor that way, and the percentage of ethanol in the gasoline will be posted on the gas pump.  Most stations that are forced to sell a 'winter blend' fuel, as required by local air quality laws, sell a blend of 90% unleaded gasoline and 10% ethanol.

Answer 2

Fuel retailers will add ethanol to their fuels, but it is to meet Clean Air Act standards set forth by the EPA.  Ethanol is an oxygenate, which means it releases oxygen during burning.  This oxygen helps your car burn cleaner and reduce emissions.   The EPA requires oxygenate in all fuels and for a while, MTBE was used, but eliminated around April 2006.  Ethanol is the only remaining available oxygenate.  The oil companies aren't trying to s***w you over, since it's more expensive to add the ethanol than it is to sell you straight gasoline, but the environmental regulations require an oxygenate.

While you do actually lose some mpg, let's calculate.  If you got 20 mpg on MTBE gasoline in your car and you switch to a 10% ethanol mix, you'd realize a net energy loss of 1.5% ( Ethanol has about 15% less energy per volume than gasoline, divided by 10 to reflect the volumetric loss of gasoline).  This puts your mileage at 19.7 mpg.  Now keep in mind, that's assuming you don't live in an RFG area, which evey major city in the US has been for over 5 years.  They've been using ethanol blended fuel for years, so you'd never see a difference.

Short answer, you're not going to see any appreciable drop in mileage due to the addition of ethanol into your gasoline.

Good question, by the way!

Answer 3

some do sell higher ethanol grades

but it is marked on the pumps or they face big fines