Ok so we drove to CT this weekend and I needed to fill up on the way home (man I love getting 540 miles on a tank of gas). So anyway when it came time to fill up I stopped at a Sonoco station and as I was filling up I noticed a rather large sticker on the pump (and in fact all pumps at this station...which was the only station at this exit) that said 10% ethanol. There isn't anything like this on the pumps in my home town and honestly I have never seen it before even when traveling.

Knowing that ethanol does not have the same energy output I assume I am going to see a loss in efficency for this tank...true? Or does all gas contain 10% ethanol and I just didn't know it?

 

For as long as I can remember, all the pumps out here in CO have signs that say "may contain up to 10% ethanol". I'm not sure how it would affect FE since it is all my current vehicles have ever seen.

 

Sad to say, I don't think anyone except possibly the tank farm that fills the trucks even knows and even then, I'm not sure.

I don't think it is possible to measure the specific gravity of a sample to even get a rough idea of the percentage:

711.22 - gasoline, natural
737.22 - gasoline, vehicle
789.20 - ethyl alcohol

http://www.csgnetwork.com/specificgravliqtable.html

The variablility in the two specific gravity listings for gasoline would completely mask small percentages of ethyl alcohol.

I just don't see a cheap, field assay to measure the percentages and I sure don't trust the placards. Even dry ice is not cold enough to separate the gasoline from the ethanol. There may be a chemists who might propose a field test . . . I never took organic chemistry.

Bob Wilson

 

If it has any effect it will be very minimal. Here's a validating quote:
The upside on the use of ethanol blended gasoline is as follows:
So generally speaking, using 10% ethanol blend apperas to be more positive than negative for most drivers that can fillup at the gas stations that offer the blend.

I've been using ethanol blended gas exclusively for the last 4 years specifically for the reasons outlined above - and I do not regret it.

Regards;

MS

 

California has switched from MTBE to 10% ethanol early this year. I doubt you will see any mpg change. It is quite likely you have been using ethanol and just not noticed.

I've got 2 fillups on my TCH and am averaging 42mpg. I've got 519 miles on the 3rd tank and the tank average is showing 42.9mpg. I drive about 80% freeway, mornings have light traffic with occasional slowing, evenings are rush hour traffic, often taking a hour or more to go 25 miles.

 

Thanks for the feedback, I was sure I would get a good answer here.

 

Since MA switched over to the reformulated 10% ethanol mix, I've noticed about a 3 mpg hit. Using the same lightfooted techniques as before, I can't seem to manage anything higher than 50-52 mpg these days.

 

I assumed all CO gas was 10% ethanol too until a few months ago. I notice a Conoco station just outside of Boulder that had a big sign advertising 100% Real Gas - No Ethanol so I gave it a try. The weather had just started to warm up as well so the mileage jumped for multiple reasons but I my last 2 tanks were 29.7 and 31.3. My warm weather average prior to that was only 28.1. At the same to 4c price premium I'm sticking with this gas for the time being.

 

May I ask where the station is? I'm in Boulder at least once a week. I would like to test it out and see if it makes a difference for me too.

Thanks.

 

75th and Arapahoe. If you make it there, and you like good beer, stop by Avery Brewing Co. at 57th and Arapahoe. I brew there and we have free beer in our tasting room. Anywhere between 5% and 18% ethanol.