At gas station

>at gas station
>see ethanol free premium
>also "normal" premium

I went with ethanol free and it's the first time I've ever seen it. What's the difference?

Less power

Its for cars that don't have ethanol-friendly fuel systems. Ethanol eats at lines and hoses and shit in older cars.

Ethanol is not good for the seals and valve seats found in most marine engines. Seeing as it says aloha, I'm guessing Hawaiian station. Ethanol doesn't have the same properties as gasoline as it technically has a high octane rating (knock resistance) but you have to burn more of it to get the same effect as straight gas. You would likely see a small increase in economy going with straight gas over blended or E85.

No dumbass pure gasoline for untuned cars most certainly produces more power and you better believe manufacturers use pure gasoline when determining HP numbers.

Gasoline's energy content is higher than that of ethanol so pure gas in any car will give you 3% more power vs gas cut with 10% ethanol.

Also, with pure gas most people see a ~5% improvement in MPG's.

Also, pure gas can sit around a lot longer being unused VS ethanol cut gas. Pure gas is also much better for small 2 stroke engines.

Pure gas also doesnt mess with rubber seals like ethanol cut gas does.

Thats why some people will only buy pure gas.

I want all 170HP my 1.8t gives me so I buy pure gasoline.

>What's the difference?
Ethanol-free fuel has no ethanol in it.

Fuel that isn't ethanol-free is diluted and adulterated with ethanol.

You use more of the less energy dense fuel to get the same power, dumbass. Your HP won't change and your mileage will change by a miniscule amount.

Even my 1990 suburban says in the owners manual that it's cool with ethanol blends. Manufacturers are forward thinking that way.

Petroleum fuel has a denser energy content than an ethanol mix or pure ethanol, so theoretically it will give you better MPGs

Ethanol does have a higher octane rating however, so performance wise it is the better fuel
>all those bottles of cheap octane booster you see? mainly ethanol.

Here's my question:
when you buy 91 octane and it's got 15% ethanol, does that mean the petroleum fuel was actually a lower octane before mixing? and if so, shouldn't it be cheaper since it was less refined?

ethanol doesn't affect power production.
you're still going to get your 170 hp even with pure ethanol, but your MPGs will be terrible.
>source: MCM. Running a pure ethanol setup allows you to have a richer air/fuel mix due to higher octane rating and less chance of predetonation for maaaad power
>if racers use it it's good enough for your VAG product

No because in America to save money, the gas will be used with ethanol. But it wrecks engines. So they counteract it by making ethanol resistant. Doesn't mean it makes the same power. They just don't want to have their engines having a bad rap because of poor people

>and if so, shouldn't it be cheaper since it was less refined?
lower octane gas isn't any "less refined" than higher octane fuel. Most fuels are probably over 90% similar in terms of their chemical "ingredients" and vary mostly in the relative ratios of those chemicals. Think 40:60 of part A to B relative to 60:40 A to B, not 100% A vs 100% B.

nah. octane booster is mostly Methylcyclopentadienyl manganese tricarbonyl

some people are confused about what octane and energy density means.

octane rating is how easily the fuel will burn.
energy density is how much energy it will produce when burnt.

at higher revs, it's important to have a higher octane rating because this stops knock and your engine exploding. that said, the way that fuel has been reformulated, older cars cannot cope with the different formulation because their maps are based on the assumption that the fuel will be the formulation used 20 years ago. for example there is like a quarter xylene in 95 octane fuel. it doesnt mean that the fuel is 95% octane.

>yfw BTFO

>wrecks engines
huh, that's why there's so many alcohol burning VW Beetles then.
>hell it probably cools those poor boxer engines better too

>ethanol resistant engnies
you mean any engine ever? Most problems with it come from fuel delivery systems, which means OH NO you have to get some new rubber fuel lines.

>doesn't mean it makes the same power
I will admit that when you switch to full ethanol you will want to retune, but usually to use MORE fuel

> They just don't want to have their engines having a bad rap because of poor people
back to the bus with the likes of you

If you're a biker, it's like the difference between the amber nectar of the gods and a tepid Budweiser.

>you're still going to get your 170 hp even with pure ethanol

No, I most certainly will not. The energy content of ethanol is lower and UNLESS tuned you will have less power and trash MPG's.

Also, why do you think EPA MPG estimates are lower for a given car when ethanol is used???? Its trash fuel unless tuned for it.

The only reason it exist is because

>muh government subsidy for corn farming
>Muh alternate fuels.

>muh artifically inflated 100$/barrel oil prices
now that's over, america can prepare for another dustbowl when burning arabs is cheaper than burning corn.

I do love me some cheap pure 93 octane good for 242 HP/293 Tq in my 1.8t.

>Holiday now carrying no ethanol premium
>put it in Jeep
>no extra power or smoothness
>exhaust burble x10
Would spend 50 cents more per gallon again

Premium is always ethanol free here unless stated otherwise.
Ethanol in premium fuel. That's fucked

You idiot, if your fancy 1.8t has any sort of O2 sensor then it will compensate for the 3% lower energy density of e10 fuel. You have more of a difference in power with a change in altitude (which your car will compensate for) than with pure gas vs e10. Your O2 sensor will flag a lean due to e10, richen it up a bit and continue on with its normal life, just as if you had gone to a lower altitude. You use more of a less energy dense fuel to get the same energy, what is so hard to understand?

Energy density is the amount of energy released per unit weight of the fuel when fully oxidised. Some fuels such as ethanol have a lower energy density, but burn fully with a lower air/fuel ratio, and therefore can be run richer than gas. This manifests as an increased power output over straight gasoline at the expense of fuel economy. Most engines' power is limited by their ability to breath, and ethanol allows them to extract more energy from each combustion cycle without needing as much oxygen. Any car built to cope with ethanol will be able to adjust for this.

>o2 sensor
>compensating for lower octane fuel
Stop posting anytime

>not knowing dick about cars
Stop posting anytime.

O2 sensor is downstream of combustion. It measures O2 in exhaust. Too much means you're not putting enough fuel in (lean), too little means you're running rich. ECU compensates the fuel injectors to run where it wants. Feedback system, dicknuts.

So I yes, the O2 sensor allows the engine to adjust the fuel mixture to compensate for low or high energy density mixes.

Also energy density not equal to octane. So even if you had memequoted correctly you'd still have been wrong. On the Internet of all places.

Pretty much every station in my town:
>All grades contain up to 10% ethanol

Get a flex sensor and a tune then your shitty 1.8t will make 220hp instead of 180hp.

As some anons have said, there are some engines that weren't designed to use ethanol blends. This is also true of a lot of farm equipment and small engines. One of the biggest problems with ethanol is actually that it is less stable, so you can't leave it sitting for as long.

All modern cars will be fine with a small amount of ethanol, all the manufacturers know most of the gas people are going to get will be e10. You won't see any kind of power difference with e10, and you probably won't notice too much of an mpg drop either.

The power thing is because of oxygen sensors and how they will compensate for fuels. They aren't perfect, though, and that's why ethanol/flex fuel sensors exist. Most, if not all cars that aren't customized will have "narrow band" 02 sensors. these only work at very close to a stoichiometric mixture. You need a wide band sensor unless you have your tune really nailed down like the oem's do. This means it'll do fine with e10, but don't think throwing e85 in any old car will work.

The problem in cars with e10 is a lot of gas statins don't actually have e10. A lot of times they cut it with more ethanol than they say, and that's when it could start being a problem.

About the whole can you make more power with ethanol thing, yes you can. It has to do with the energy density, the weight density, the stoic air fuel ratio, and some other stuff. But in general, "you have to use more, but it makes more power" is true.

Its free of ethanol

Ethanol kills carburetors and ruins jets. Also ruins fuel lines in older vehicles. that and it smells awful and boils off in said carb causing the car to reek from 30ft away.

Ethanol is heavily subsidized, actual costs are higher than normal gasoline.

>go buy two fuel stations on my daily route
>one is usually slightly more expensive than the other
>some weeks the prices sar but this station always stays pretty low by comparison
>finally decide to stop in and fill up on cheap premium
>91RON has 15% ethanol, 94RON has 15% ethanol, 100RON has 10% ethanol (i also thought 100RON octane was discontinued worldwide)
>can't use any of that shit because ethanol is shit
>pass it by again and just pay the extra for the ethanol free premium

This nigga must be rich as fuck
>buy 2 fuel stations