Changed Gas Stations, fuel economy up 10%

I'm in Colorado, and have been using Safeway gas since I got my car, then my wife filed it up with Diamond Shamrock and I immediately noticed a 10%+ increase. Anyone else have a similar experience?

I'm will into my 2nd DS tank and it is even better than the 1st one. Averaging an indicated 22.8 around town which should be in the mid 21s when I calculate it at next fill. This is up from mid 19s with Safeway.

make sure the gas station you go to isn't using ethanol and you should be good.

I changed and got 300+ miles on a tank.

Hmmm... Yes ethanol increases octane but decreases power in gasoline engines. Ethanol has a lower specific energy than gasoline.

Internal combustion engines need to have much higher compression to take advantage of ethanol's potential. That doesn't seem to be happening anytime soon.

I don't think 10% ethanol will make a major difference however. It would have to be a much more substantial percentage.

Hmmm... Yes ethanol increases octane but decreases power in gasoline engines. Ethanol has a lower specific energy than gasoline.

Ethanol burns faster than gasoline which allows reduced spark advance and more efficient torque development and reduces the magnitude of cycle-to-cycle variations.

Ethanol combustion generates a larger volume of combustion products than gasoline which means higher cylinder pressures and faster turbo spoolup.

Hmmm... Yes ethanol increases octane but decreases power in gasoline engines. Ethanol has a lower specific energy than gasoline.

 

Internal combustion engines need to have much higher compression to take advantage of ethanol's potential. That doesn't seem to be happening anytime soon.

 

I don't think 10% ethanol will make a major difference however. It would have to be a much more substantial percentage.

it does, trust me.

Don't quote me, but I heard that some of the wholesale sellers like BJ's and such don't put the same kind of additives in the gas they sell. One guy if I remember correctly said that he ran gas from Chevron once a month to overcome the degradation he got from that gas. He drove a mercedes C-class.

Don't know if its true or not but if my memory is right then you are the second person I have heard this happened too.

a slow gas station

I need to see if my station sells slow gas or fast gas.

"E85 has been repeatedly shown to produce more power than a comparable gasoline fuel. Especially in engines that need high octane fuels to avoid detonation.[7] Ford Motor Company found typically power increased approximately 5% with the switch to E85 [8]. Researchers working on the E85 equivalent fuel for general aviation aircraft AGE-85 have seen the same results with an aircraft engine jumping from 600 hp on conventional 100LL av gas to 650 hp on the AGE-85. Recorded power increases ranging from 5% - 9% depending on the engine. [9][10]"

Quote from Wikipedia

http://aaae.okstate.edu/proceedings/2005/Articles/556.pdf

also read this

We have Wal-Marts selling gas in my area under the brand name "Murphy."

I wouldn't put that stuff in my baby.

The question is- is there any way to "overcome" the inevitable mandatory switch to the 10% etoh addition to our fuel aside from maybe switching to Cam2 in every tank? Would there be any validity to octane "boosters"?

Off the shelf octane boosters do little to raise octane in the quantities they're sold in; besides ethanol is an octane booster

Was the Safeway a slow gas station? I do know that using a station that has good business helps prevent the gas from getting too old and collecting dirt or other things.

no they have lines out to the road on some days

"E85 has been repeatedly shown to produce more power than a comparable gasoline fuel. Especially in engines that need high octane fuels to avoid detonation.[7] Ford Motor Company found typically power increased approximately 5% with the switch to E85 [8]. Researchers working on the E85 equivalent fuel for general aviation aircraft AGE-85 have seen the same results with an aircraft engine jumping from 600 hp on conventional 100LL av gas to 650 hp on the AGE-85. Recorded power increases ranging from 5% - 9% depending on the engine. [9][10]"

 

Quote from Wikipedia

bull, when I drove cross county with my tundra the higher ethanal blend the worse fuel economy I got

Higher octane... Yes.

Less Specific Energy... Yes also.

Ethanol is harder to burn, and releases less energy per unit than gasoline.

SO... You can run higher compression, and theoretically get more power without pre-detonation. BUT you will also get much less economy, as you have to dump MUCH MORE fuel into the mix to get that much heat/kinetic energy out. Somewhat more fuel for the same power, Lots more fuel for more power, and moreso as the ethanol content increases.

Higher octane is not the only thing to consider. and higher octane does not mean the fuel generates more power, and sometimes means it generates less power, depending on the engine.

This does less-than-nice things to engines that are designed with modest compression and little timing advance, and no forced induction. Higher octane, harder to burn fuel with less energy content actually does worse things to these engines than higher compression performance engines. That includes most economy cars, and most implement and small engines. Worse economy AND less power.

PLUS, there is the matter that with this new fuel mandate, US supplys of ethanol aren't enough to supply at all times, so they are considering, or already are importing ethanol from Brazil and other countries, BUT, imported ethanol is as expensive or moreso than the gasoline, due to protective tariffs, to protect the same corn and sugar producers that insist that the government mandate ethanol use.

Not to mention that somewhat negates the part about "lessening foreign dependence..."

Politics. In't it great? :meh:

']Although ethanol has a Lower Heating Value (MJ/kg) of only 26.8 compared to approximately 42.7 for gasoline' date=' ethanol's [i']specific[/i] energy is higher than gasoline's because you need/get to supply 62% more ethanol to react with any fixed amount of air. This is because ethanol's stoichiometric A/F ratio is 9:1 whereas gasoline's is approximately 14.6:1.

 

Ethanol burns faster than gasoline which allows reduced spark advance and more efficient torque development and reduces the magnitude of cycle-to-cycle variations.

 

Ethanol combustion generates a larger volume of combustion products than gasoline which means higher cylinder pressures and faster turbo spoolup.

Most of this sounds correct. And turbos should run better on it. Effectively, our compression ratio when on boost is probably somewhere around 20:1 (guesstimate). Most production turbo engines run pretty rich at 10 or 11:1, so compared to a NA engine, we should be running ethanol fuels closer to their optimum.

Based on my results with E10 fuel, it bears out most of what Jon said. I get less hesitation on hard acceleration and it seems to respond to throttle input better, which means less mashing of the pedal. more efficient torque generation and the fact I'm driving a 5EAT means that I have the most to gain from both those things.

Since getting E10 fuel around here, I'm seeing about 1.2-2mpg better fuel economy than before. (but I don't do much extended highway cruising due to traffic and such, so can't say if it makes it harder to be efficient in that mode, which might be the case). It's probably less efficient, but I'm liklely running into less of the "rapid boost and throttle input increase, so dump fuel to quench heat" portion of the ECU code.

bull, when I drove cross county with my tundra the higher ethanal blend the worse fuel economy I got

What you quoted had nothing to do with fuel economy. Just the power produced by the engine. With ethanol you will get worse fuel economy cause ethanol needs to run at a much richer mixture. Now if the mixture is setup right around (7.0 afr when a gas motor likes about 12.0 for max power which also depends on the motor) the ethanol motor is said to make about 5% more power. But your fuel economy will suffer. Most flex-fuel cars and trucks quote about 25% less economy according to the epa.

Here is a website with specific energy output of certain fuels.

http://hypertextbook.com/physics/matter/energy-chemical/

I've operated a service station for 30 years

When ethanol is mixed with reformulated fuel it actually increases octain.

so over the next few months depending how your state is mandated there will be a lot of mixing going on. Although some suppliers will stick with Ethanol PERIOD!

Some suppliers will buy whats ever cheaper. Getty (Luke Oil) Is all Ethanol.

Hear is where the problem is. Ethanol turns to gel when mixed with water, causing filter and injector problems. Also causes swelling in some seals(older cars) even in older pump dispensers. Thats one of the reasons gas has taken another hit (in price), All the refineries started to clean out their storage facilities (get ready for new Ethonal) Well guess what they found out "IT CANNOT BE SHIPPED THROUGH EXISTING GAS PIPELINES" so now it has to be trucked or trained throught the country. and no one was ready for it. Thats what Bushe's speach on suspending mandates for Ethonal fuel 2 weeks ago came to play, other wise gas right now would be well over $4.00 a gal.

I know everything there is to know about gas and state regs. States have different regs on types of fuel needing to be used. But the feds are useing that old hwy funds to force states to use what ever puts money in their(feds) pockets.

Currenty a huge contract was awarded to supply ethanol- kickbacks, payoffs, PACS, Tons and tons of money flying around DC(were talking Billions$$) to be made here. Imagine an agreement to supply cornoil (Ethanol) to cover 10% of our nations fuel supply!!! And they will force it down our gas tanks!

Its been documented in trade books, if they did away with all additives and sold the same gas that we had in the 60's your same car today would get up to 35-50% better gas mileage and polute less! In the early seventies my vega used to get 33MPG I got 55 on my bike with 110HP. With all the teck stuff today a sube still gets only 27-35MPG.

Whats wrong with that picture.