10 % ethenol??

pastor scott.com · June 17, 2005

my MPG has dropped since using gas with the 10% Eth in it. Is that a factor?

Scott

mmmikkke · June 17, 2005

my MPG has dropped since using gas with the 10% Eth in it. Is that a factor?

Scott

<{POST_SNAPBACK}>

Theoretically, since the energy content of a gallon of ethanol is only about 70% of the energy content of a gallon of conventional gasoline, your mileage should drop by about 4% when you're using gasoline containing 10% ethanol.

Others dispute this and claim mpg increases.

I touched a nerve by raising this issue, and an ensuing heated debate, in another thread here at gm-trucks.com. Click here.

ness5575 · June 17, 2005

using gas with ethanol will decreases mileage.

I live in a county where ethanol (10% ethanol) gas is required, about 10 miles down the road (next county over) it is not required. so i have lots of experience using and not using it, and my mileage is always 1-2 mpg better with the non-ethanol stuff.

other than that there is no trouble with it. I cant tell any difference at all performance wise on the truck...

Norseman · June 17, 2005

my MPG has dropped since using gas with the 10% Eth in it. Is that a factor?

Scott

<{POST_SNAPBACK}>

I have not noticed any real measurable differance.

Elwood 2000 · June 18, 2005

This is odd. Around here, I use only ethanol gasoline and when I travel and it is not available, my milage DECREASES slightly without it.

Mmmikkke, that debate was not heated at all!

fyarbrou · June 18, 2005

Don't know if it is true or not but my brother who works at a GM dealership told me not to use any gasoline with ethanol in it on a regular basis. He said that using the ethanol gas occasionally was ok and would help get rid of moisture but long term use would eventually harm the rubber O-rings in the fuel injectors. It sounds reasonable to me.

Fred

BlueTahoe · June 18, 2005

I have heard this in the past too. As I looked into this a little further this was really intended for old cars. 60's & 70's. Some old rubber o-rings, fuel lines would deteriorate from the ethanol.

I have a Tahoe from GM that runs on up to 85% ethanol and from what I have been told most all parts on mine are the same as the non-e85 models. Just some bigger fuel injectors and extra fuel sensor to adjust for fuel delivery rates base on ethanol content.

I believe this is a left over from when ethanol was first being used and there were allot of these older cars still on the road. You should be safe to run a 10% ethanol blend in any car made in the last 25-30 years.

As far as mileage. Looking at the facts a 10% blend of ethanol should decrease mileage BUT most places selling a 10% ethanol have an octane of 89 or above because ethanol increases octane. Some people may be seeing an increase in mileage due to the increase in octane of most 10% blends. So 87 octane gas compared to 89 octane 10% ethanol some may see differing results depending on the difference in octane levels. This may be one factor that we are overlooking.

I have had vehicle that run tons better with higher octane and have had some that have zero noticeable difference. Had 1 car, 82 olds cutlass, that it saved me money to run 93 octane becuase the MPG increase more that offset the added cost.

mmmikkke · June 18, 2005

Mmmikkke, that debate was not heated at all!

<{POST_SNAPBACK}>

Passion is a gift from God, it's good to exercise it once in a while.

treebumper · June 19, 2005

The "Blue Planet" gas that is sold here in Minnesota has a higher percentage of ethanol(I can't find out exactly how much), up to 85%. The gov't site states that it has 10-20% lower emissions and a reduction in fuel economy of 10-20% is normal. Wouldn't the gross emissions be higher as a result?

A friend filled my tank with this stuff a couple of weeks ago and I could definitely tell. I even brought my truck to the dealer and asked if they would take it on trade so I wouldn't have to get it fixed. I thougt I had messed it up when I put new plugs in it a couple of days earlier. The service writer asked me where I filled it up last. When I told him he just hande the keys back and told me to go fill it up anywhere but Holiday.

I only got 256 miles out of that tank(8.56 mpg) and my truck was so sluggish that I made my wife drive it until the bad gas was gone. My Father-in-law just retired from being a fleet mechanic and he said that it really only seemed to affect the Furds and GM's, the imports and Mopars just got a little worse fuel economy.

mmmikkke · June 19, 2005

That was probably what's known as E85, 85% ethanol, 15% conventional gasoline.

Most of the major manufacturers offer a few of their models as "flex fuel" vehicles, which can either run on E85, or on conventional gasoline, or anything in between. The computer notices what you have and adjusts the engine to suit. Those flex fuel vehicles feature a "gasoline" mpg and a E85 mpg, and the E85 mpg is typically 30% less than the gasoline mpg.

The fuel system on those vehicles is capable of sending a larger volume of fuel to the cylinders when E85 is being used.

Because your truck is not designed to run on E85, it probably couldn't give enough fuel to the cylinders to make it run right.

For your truck, and any other vehicle designed to run on "gasoline", you should only run up to 10% ethanol with today's blends. Any more than that and you'll experience severe drivability problems, such as "surging."

Is that what happened? Surging and bogging?

100R1 · June 20, 2005

Here is a article from the June 2005 issue of GM techlink

With the escalating cost of fuel, customers have inquired if they are able to use E-85 fuel in non E-85 compatible vehicles. Only vehicles designated for use with E-85 should use E-85 blended fuel.

The only E-85 compatible vehicles produced by General Motors are 2000 - 02 S series pickups equipped with the 2.2L L43 4-cylinder engine and 2002 - 05 full-size pickups and utilities equipped with the 5.3L L59 VIN code Z V8 engine. All other gasoline engines including all 5.3L V8 with VIN designators other than the letter Z are not E-85 compatible.

E-85 compatibility is designated for vehicles that are certified to run on a mixture of up to 85% ethanol and 15% gasoline. All other gasoline engines are designed to run on fuel that contains no more than 10% ethanol. Use of fuel containing greater than 10% ethanol in non E-85 designated vehicles can cause driveability issues, Service Engine Soon lights, and increased fuel system corrosion.

- Thanks to Jay Dankovich