Too Much Ethanol

[jhanley]

Typically, I average 13mpg, 80% city, 20% highway. Although, with the ethanol gas, I was barely over 10 mpg. Could this be accurate? My last fill up contained 11% ethanol, 87 octane.

 

[TXLX100]

Is your truck stock? Do you normally fill with ethanol fuel? Seems a bit low for a light stock 100. I use ethanol gas and get around 13-14 mpg driving 60-75 mph. Probably 11-12 mixed city driving.

 

[stonepa]

What was the temperature? Was it a winter blend versus a summer blend? Was it windy? Could be a lot of things.

 

[jhanley]

Is your truck stock? Do you normally fill with ethanol fuel? Seems a bit low for a light stock 100. I use ethanol gas and get around 13-14 mpg driving 60-75 mph. Probably 11-12 mixed city driving.

Bone stock 2004, 18'' wheels, michelin LTX's, inflated 35 psi square.

 

[jhanley]

What was the temperature? Was it a winter blend versus a summer blend? Was it windy? Could be a lot of things.

Not sure with regards to blend, but, 10mpg is an abnormal drop, as my driving habits stayed consistent.

Does ethanol typically reduce fuel economy, though?

 

[dogdaysindurham]

If you went with 100% ethanol you would only have 70-75% of the same energy for the same volume of gasoline.

http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

 

[dogdaysindurham]

But such a drop is pretty drastic.

 

[hankinid]

Closest gas station to me began selling 90 octane no-ethanol about 9 months ago...my mpg went up about 1.5mpg.

Steve.

 

[TheForger]

I regularly fill up with 87 octane and only average 10mpg......that is most likely due to my front bumper and roof rack with no fairing though. Disappointing? Yes very much so, but those are the sacrifices I must make to drive such an amazing vehicle

 

[hkeller]

They don't make the LTX M/S in stock size for18" wheels. What is your tire size?

 

[TXLX100]

Closest gas station to me began selling 90 octane no-ethanol about 9 months ago...my mpg went up about 1.5mpg.

Steve.

That's nice. You can't get it in the big cities around here. I estimate about a 10% decrease due to ethanol and your 1.5 increase might not be far off. When I cared to calculate gas mileage, I tried to fill up the same way, same station and would keep track of 4-5 consecutive tanks.

It's sounds contrived, but my ford V8 will idle bad when the fuel blend changes. I had it towed to the shop 3 years in a row around the same time and they found nothing wrong.

If you haven't already, check for any pending O2 sensor codes, clean the MAF sensor, throttle body, unhook battery, add a can of K44, and monitor it for a while.

 

[jhanley]

They don't make the LTX M/S in stock size for18" wheels. What is your tire size?

Sorry, Michelin latitude tour HP.