100% gas vs gas with 10% ethanol

[Einst-Hawk]

Just curious. Has anybody done a test to see if the extra mpg's (that's what I've always heard) is worth the cost of 100% gas?

Here in SC: 87 octane w/ 10% ethanol is around $3.19.
87 octane 100% is around $3.52

My 2004 TB averages 13.4/ a gallon - city. 25g tank and I usually end up getting 335 miles. I feel its not that bad figuring the original mpgs given for my EXT when new was 15 - city and it's now 10 years old with 167,500 miles on it. Just want to see if I can get better mileage.

I've done what I can to raise it. Changed plugs, ac delco iridium. Cleaned TB. Replaced CTS - ac delco. Changed thermostat. Alignment is good. Tires are good. All fluids have been changed. I don't drive like a granny, but I also don't drive it like I stole it either.

Doing the math: 25g x 3.52= $88.00
25g x 3.19= $79.75
8.25 Difference.

8.25 / 3.19= 2.59g more or 31.71 miles more. (13.4 x2.59)

So I would need to get at least 366 miles per tank to break even.
I am about to do this myself to see for sure. I will report my results back. Just wanted to know if anybody else has done this?

 

[davenay67]

Ethanol in gas is the devil incarnate..!!

100% gas is less harmful on the engine and fuel systems. 100% gas is more efficient as well. I would buy it if I could get it, but where i live there's nothing in a large radius from me.

I'm a motorcycle guy, and Ethanol is giving the powersports industry fits. The Euro bikes and their plastic tanks are warping and expanding beyond spec. Metal tanks are prone to rusting from ethanol's watrer absorbtion qualities. And bike engines don't like ethanol very much either.

The big challenge is that the powers that be want to increase ethanol content to 15%. This is probably going to blow a lot of bikes up.

I know this is a car site, and you don't want to hear any belly-aching from a motorcycle guy. But this stuf aint the best for our cars either....

Just curious. Has anybody done a test to see if the extra mpg's (that's what I've always heard) is worth the cost of 100% gas?

Here in SC: 87 octane w/ 10% ethanol is around $3.19.
87 octane 100% is around $3.52

My 2004 TB averages 13.4/ a gallon - city. 25g tank and I usually end up getting 335 miles. I feel its not that bad figuring the original mpgs given for my EXT when new was 15 - city and it's now 10 years old with 167,500 miles on it. Just want to see if I can get better mileage.

I've done what I can to raise it. Changed plugs, ac delco iridium. Cleaned TB. Replaced CTS - ac delco. Changed thermostat. Alignment is good. Tires are good. All fluids have been changed. I don't drive like a granny, but I also don't drive it like I stole it either.

Doing the math: 25g x 3.52= $88.00
25g x 3.19= $79.75
8.25 Difference.

8.25 / 3.19= 2.59g more or 31.71 miles more. (13.4 x2.59)

So I would need to get at least 366 miles per tank to break even.
I am about to do this myself to see for sure. I will report my results back. Just wanted to know if anybody else has done this?

 

[HARDTRAILZ]

I would love to use real gas but its not available nearby

 

[Einst-Hawk]

Ethanol in gas is the devil incarnate..!!
.

I know this is a car site, and you don't want to hear any belly-aching from a motorcycle guy. But this stuf aint the best for our cars either....

No offense taken. All opinions are welcome.

You are right. Ethanol isn't what is best for engines. But Washington decided that corn is what makes things go. - Snark

 

[HARDTRAILZ]

Corn is for eating.

 

[Robbabob]

Corn is for eating.

I thought it was baiting deer...

I am one of the luckiest drivers... I have my choice of two 100% stations in very convenient directions. Pay roughly $.30 more per gallon for my Dakota. Our TB, driven by the wife so it's hers to choose, gets discounted gas (Bi-Lo & Shell partnership) with the 10%.

Oh, BTW, both motorcycles get the 100%. Should make her put it into "her" jet ski, too.

 

[MAY03LT]

I thought it was baiting deer...

I thought they were a band.

I would be all over 100% if we had it here.

 

[Mooseman]

Just at the end when we could still get E0 id regular gas, I did a simple test. Ran a tank of each alternately and I consistently got less MPG with E10. Ever since E10 has been mandatory in regular, I blew up a few 2 stroke snowmobile engines. The only way to get E0 now is in 91 octane premium gas. Not worth it for the daily drivers but I use it in my snowmobiles, both 2 and 4 stroke.

 

[Einst-Hawk]

I thought they were a band.

Love it!

View attachment 33685

 

[bobdec]

Please post your test results, I would be very interested to see how the 4.2 does on 100%.. I know with 100% the PCM uses 1 gram of fuel to 14.7 grams of air and with E10 1 gram of fuel to 14.13 grams of air so it's adding 3.8% more fuel with E10. However E10 has a bit more power per gallon that offsets to richer mix.

I will stay clear of the E10 or E15 debate, as a boater there are plenty of threads of the effect on older boats. Our marina only pumps 100% due to that. And don't ask about effect of E10 on yard equipment like blowers and chainsaws that are stored with fuel in the tanks..

 

[Envoy_04]

I wish the gas prices here and a home were like the OP's! Our 87 E 10 is in the 3.60s and for non-ethanol 90 octane ( the only E0 gas you can get around home) you'll pay 4.20-4.35. It isn't quite worth it for me to run in the Envoy since it only has netted me 1.5 to 2 MPG difference in the past, but its the ONLY gas I'll run in my 93 S10. I ran a tank of E10 in that truck, once. It wouldn't idle worth a darn, it just seemed like there was no power, and the mileage on that tank was like 15 MPG, For a truck that otherwise had a record worst of 17!

 

[dmanns67]

Not sure if this site has been posted before, but it lists all gas stations by state that sell ethanol free gas. It also has a nice feature to map your current position and show you the closest gas station to you.

Ethanol-free gas stations in the U.S. and Canada.

There is only one station close to me, but they only sell 87 octane. Would not be a big deal if it wasn't for my PCM being tuned for 93 octane.

 

[Blckshdw]

Not sure if this site has been posted before, but it lists all gas stations by state that sell ethanol free gas. It also has a nice feature to map your current position and show you the closest gas station to you.

Ethanol-free gas stations in the U.S. and Canada.

There is only one station close to me, but they only sell 87 octane. Would not be a big deal if it wasn't for my PCM being tuned for 93 octane.

Looks like any of the ones I'd be able to hit between home and work are offering 89 or 90 octane, so I have the same dilemma cuz of my tune.

 

[Einst-Hawk]

Well, It's been a week and here are the results of my test.

Filled up last Wednesday with exactly 25.0 gallons of pure 87 gas. When I filled up again today, I pumped 25.1 gallons in.

I got 346.2 miles. That's 13.793 miles/gallon. Whereas on average with 10% gas, I get 335 miles at a 13.4 miles/gallon ratio. I had a gain of 11.2 miles. Not the significant gain that I had hoped for. But it was an improvement.

Now of course, this was in no way a 'scientific test' since I only did it once. Lots of other factors could influence the mileage of anybody else truck and get better or worse mileage than me.

For me, the cost of pure gas does not win this time around. I'll have to stick with the corn for now.

 

[DDonnie]

I thought it was baiting deer...

View attachment 33911

 

[{tpc}]

Not sure if this site has been posted before, but it lists all gas stations by state that sell ethanol free gas. It also has a nice feature to map your current position and show you the closest gas station to you.

Ethanol-free gas stations in the U.S. and Canada.

There is only one station close to me, but they only sell 87 octane. Would not be a big deal if it wasn't for my PCM being tuned for 93 octane.

Thanks for this, I was about to ask. Of course, as I suspected, nothing in michigan close to me and the closest are marinas.

At least I don't have to feel bad about it or search it out now! lol

 

[glfredrick]

Please post your test results, I would be very interested to see how the 4.2 does on 100%.. I know with 100% the PCM uses 1 gram of fuel to 14.7 grams of air and with E10 1 gram of fuel to 14.13 grams of air so it's adding 3.8% more fuel with E10. However E10 has a bit more power per gallon that offsets to richer mix.

I will stay clear of the E10 or E15 debate, as a boater there are plenty of threads of the effect on older boats. Our marina only pumps 100% due to that. And don't ask about effect of E10 on yard equipment like blowers and chainsaws that are stored with fuel in the tanks..

I've tested several tank fulls of the mid-grad non-ethanol in my Toyota Rav 4 and the non-ethanol comes out on top by a worthy margin, even considering the price differential. Thankfully, I can purchase that sort of fuel in my area at select stations.

Over multiple tanks, the Rav sees 24.9 mpg average (calculated) with regular grade 10% ethanol from top tier stations like Mobil. It will drop to as low as 21 mpg with God only knows what is sold at lower-tier stations -- yes, the difference is THAT drastic!

Over 2 tankfuls during the same weekend (did 600 miles and thought it would be a good time to test) using mid-grade non-ethanol I saw 28.1 mpg on tank 1 and 27.2 mpg (with an additional 400 pounds in the car and some additional weather factors like more wind late in the trip) for tank 2.

On the re-fill Monday morning with regular grade 10% ethanol, I am now looking like I'm back under 24 mpg, as the half tank mileage is dramatically reduced from what it was with tank 1 of the mid-grade non-ethanol (210 miles versus 160 miles).

I did the math and even with the $0.20 a gallon higher cost for the mid-grade, I still come out on top by a figure of around $5 per tankful with the additional miles gained.

I have not noticed as drastic a change with the Trailblazer, but it is in dire need of a tune up and I will re-check after I have a change to go through it and get it back on par after a really rough winter season.

Here is a nice calculator that will allow one to play with COST PER MILE versus MILES PER GALLON. Need to know miles per gallon to use the calculator and it is always best to CALCULATE miles per gallon instead of trusting dashboard computers, which can only average based on engine conditions. To calculate divide the number of gallons on a fill (to the same point, i.e., when the pump shuts off automatically) into the total number of miles. The answer will be actual miles per gallon over the entire tankful.

Cost of Driving Calculator

To narrow down costs, here is an additional calculator that gives you cents per mile. How important is that? Depends on how many miles one drives in a given year. A one-cent-per-mile difference might not seem like much up front, but over 20K miles it can add up to significant dollars! All things being equal (service, payment, miles driven, registration fees) except fuel cost and miles per gallon, I save over $400 a year on the Rav by switching to the non-ethanol fuel even at a $0.20 cents per gallon additional price!

http://www.nytimes.com/packages/html/business/20060510_LEONHARDT/cost_per_mile.html

 

[{tpc}]

I'm also going to add in here that proper tire inflation might also make a significant difference in mpg. My car is an avenger and when I got it, I spent a considerable amount of time tracking and discussing this on another forum. My findings were that, at least on that car, if you inflate the tires just a bit more over what's on the door panel, mpg went up, with no significant detriment to handling or performance. I believe my increases were something like 3-4 mpg...or close to it.

Now some will say that it can make your tires wear funny or whatever. I suppose if you severely overinflated them it might, but that's not what I was doing, maybe 3-4 lbs more than the panel. Plus I am a believer in tire rotation, and typically I rotate my tires every oil change, except in the winter when it's too cold and too much a pita to do so.

I got over 100,000 miles on the original tires. On my second set now since I've owned the car and the clock is at 162k.

Now with a truck, this might be a different story, but thought I'd share.

 

[Trios]

One thing to note...at least in my area, the gas contains UP TO 10% ethanol. From what I've read, it seems like it's more likely to be around 5% and sometimes they mark all the pumps that way even if they're selling pure gas. So, your economy difference might not be what you expect, because your 10% ethanol fuel might really be 2%.

 

[Harpo]

I think it's strange that you experiencing such a difference between pure gas and E10 fuel.

Due to the astronomic gas prices here in Sweden I use to mix 1/3 of E85 and 2/3 of E10.

E10 is the only gas you can get here.

I have been using this mix since last summer and my fuel consumption is up 8-10% compared to just using E10.

I have tried to drive with 80% E85 but that triggered Cel and lean mix code. It is possible to use just E85 if you tune the PCM to use it.

I then saw a 25-30% increase in used fuel.

The mix I use is saving me quite some money since the price difference is almost $1 per litre.


If I would put less than 1/4 of E85 in the tank I don't see any decrease in milage at all.

 

[HARDTRAILZ]

E85 kills the mpg in our van by 1/3.

 

[High Voltage]

My truck has a gas engine in it NOT an alcohol engine! Burn gas! Eat corn!