Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - I want to get to the bottom of this ethanol killing my mpg

Nerys · 10-05-2009, 10:41 PM

What gets me irritated is when all my very clear (on my end at least) data says ethanol is a problem. NOW this does not mean its ONLY ethanol. the addition of ethanol might cause "other" issues that are not an issue outside the presence of ethanol. (water absorptions conflicts with additives etc.. etc..) but in the end the core issue is these were not "issues" until the addition of ethanol.

Oddly enough ethanol percentage SEEMS to be pretty consistent at each gas station.

I have measured the ethanol content at Wawa's in both PA and NJ well over a dozen times and its always 6-8% (its one of the reasons I buy most of my gas at Wawa as I can just manage to get 19mpg with the Cherokee on 6-8%

When I goto the cheapy station that reads 10-11% ethanol (which I have used for over a decade with ZERO performance difference from wawa or anywhere else prior to ethanol) I get 14-15mpg OR LESS sometimes.

thats why it seemed to me to make sense. Test the gas first. Determine IS IT the fuel or IS IT my cars. while all my data says 99% certain its the fuel its really is in the end just "hearsay" if you will.

it really could be a giant coincidence that all 8 of our vehicles just had something go wrong with them that we have not located a fix for yet. No one has yet to tell me what that might be. but I fully admit its possible.

"maybe" there is some common factor between all our vehicles that makes them more "prone to issues" with ethanol that is somewhat unique to our vehicles?

I have no idea what. 2 AMC Jeeps 2 Fords and 2 Chevies 1 Plymouth

I will take any suggestions you guys can give me. What to test what to check but you would need to tell me HOW to do it or point me to a URL for how to do it.

My economy drop is relatively consistent and very consistent to %ethanol. when I get gas at a station with more or less ethanol I 100% of the time get less or more mpg. I tested this over some 45-50 tanks testing the ethanol each time comparing to the MPG achieved. I tend to run my tanks pretty dry usually down to 2 or 3 gallons left so the "left over mix" is usually not much to worry about. (20 gallon tank in the jeep 35 gallon tank in the Clubwagon)

I found that Valero's and "no name" gas stations had the absolute highest ethanol levels. 10-12% none of them likely had 12% thats just what my little test tube told me. ACTUAL ethanol content was not as important to me as "relative" ethanol content.

Sunnoco on Rt73 (did not test any other sunnoco's) and the 3 Wawa's I tried all had the lowest ethanol content 6-8% I test the wawa on 13 in bristol pa the wawa 5 miles from EHC toward AC and the Wawa down in pleasentville. All the same.

so I only buy gas at those places regardless of price. Thankfully they are usually on the competitive side of the price range too.

Soo have at it tell me what you want me to do. If it requires expensive equipment I don't already have your out of luck I am about as broke as them come.

10-05-2009, 10:41 PM	#106 (permalink)
Nerys Grrr :-) Join Date: May 2008 Location: Levittown PA Posts: 800 Cherokee - '88 Jeep Cherokee 90 day: 19.44 mpg (US) Ryo-Ohki - '94 Geo Metro Xfi 90 day: 50.15 mpg (US) Vger 2 - '00 Plymouth Grand Voyager SE Ninja - '89 Geo Tracker 90 day: 30.27 mpg (US) Thanks: 12 Thanked 31 Times in 25 Posts	What gets me irritated is when all my very clear (on my end at least) data says ethanol is a problem. NOW this does not mean its ONLY ethanol. the addition of ethanol might cause "other" issues that are not an issue outside the presence of ethanol. (water absorptions conflicts with additives etc.. etc..) but in the end the core issue is these were not "issues" until the addition of ethanol. Oddly enough ethanol percentage SEEMS to be pretty consistent at each gas station. I have measured the ethanol content at Wawa's in both PA and NJ well over a dozen times and its always 6-8% (its one of the reasons I buy most of my gas at Wawa as I can just manage to get 19mpg with the Cherokee on 6-8% When I goto the cheapy station that reads 10-11% ethanol (which I have used for over a decade with ZERO performance difference from wawa or anywhere else prior to ethanol) I get 14-15mpg OR LESS sometimes. thats why it seemed to me to make sense. Test the gas first. Determine IS IT the fuel or IS IT my cars. while all my data says 99% certain its the fuel its really is in the end just "hearsay" if you will. it really could be a giant coincidence that all 8 of our vehicles just had something go wrong with them that we have not located a fix for yet. No one has yet to tell me what that might be. but I fully admit its possible. "maybe" there is some common factor between all our vehicles that makes them more "prone to issues" with ethanol that is somewhat unique to our vehicles? I have no idea what. 2 AMC Jeeps 2 Fords and 2 Chevies 1 Plymouth I will take any suggestions you guys can give me. What to test what to check but you would need to tell me HOW to do it or point me to a URL for how to do it. My economy drop is relatively consistent and very consistent to %ethanol. when I get gas at a station with more or less ethanol I 100% of the time get less or more mpg. I tested this over some 45-50 tanks testing the ethanol each time comparing to the MPG achieved. I tend to run my tanks pretty dry usually down to 2 or 3 gallons left so the "left over mix" is usually not much to worry about. (20 gallon tank in the jeep 35 gallon tank in the Clubwagon) I found that Valero's and "no name" gas stations had the absolute highest ethanol levels. 10-12% none of them likely had 12% thats just what my little test tube told me. ACTUAL ethanol content was not as important to me as "relative" ethanol content. Sunnoco on Rt73 (did not test any other sunnoco's) and the 3 Wawa's I tried all had the lowest ethanol content 6-8% I test the wawa on 13 in bristol pa the wawa 5 miles from EHC toward AC and the Wawa down in pleasentville. All the same. so I only buy gas at those places regardless of price. Thankfully they are usually on the competitive side of the price range too. Soo have at it tell me what you want me to do. If it requires expensive equipment I don't already have your out of luck I am about as broke as them come.