Non-Oxy Fuel

[MrFunk]

Anyone running non-oxy fuel? I just gassed up with a tank of Shell 91 Oct Non-Oxy fuel... car feels slightly stronger actually compared to the 91 Oct Reg fuel I was getting from Holiday.

I know this is somewhat a debateable topic but anyone else with experiance running Non-Oxy Fuel? This is my first tank in this car. I can also get 93 around town (reg fuel) so just trying to figure out what would be long term best for the car.

[phillips2024]

Hm.. A b8 s4 collector car :)

[MrFunk]

Hm.. A b8 s4 collector car :)

With all these new fancy 13's rolling around I figured I'd earned the right

[phillips2024]

Hah touché

[dparm]

Non-oxygenated means "without ethanol". Modern engines MUST work with E10. Ethanol is actually a good cleaner so running it in the gas is not necessarily a bad thing. For cars that aren't driven much, non-oxygenated gas can build up more moisture in the tank.

Moar reading:
http://epa.gov/OMS/regs/fuels/ostp-3.pdf

[MrFunk]

Non-oxygenated means "without ethanol". Modern engines MUST work with E10. Ethanol is actually a good cleaner so running it in the gas is not necessarily a bad thing. For cars that aren't driven much, non-oxygenated gas can build up more moisture in the tank.

Moar reading:
http://epa.gov/OMS/regs/fuels/ostp-3.pdf

But which burns cleaner, gives better mileage & better power? I've read a lot of opinions that non-oxy fuel is just better because it's more pure.

[dparm]

You're using top-tier 91 or better octane gas. It's full of cleaners (some brands more than others). You also have direct injection so some of those cleaning properties for valves and such are irrelevant. The car is designed to run and develop its rated power on 91-octane E10. Be glad the E15 bill died, as that would've definitely robbed some power.

Does "E0" run better? Maybe. I doubt you'd feel it. If your car sits for months at a time, you might have issues. Supposedly the shelf life of E10 is 90 days.

Find E0 stations here:
http://pure-gas.org/

[BlueByU]

BP 93 FTW!

[helix139]

You'll definitely notice a MPG increase with E0

[NWS4Guy]

Ethanol has more octane rating, meaning it will be less likely to pre-ignite, lending to the possibility of more advanced timing without knock, however from composition standpoint, it has less overall potential energy, and as such will give lower power and MPG. Specifically the same amount of ethanol has 34% lower energy than pure gasoline fuel. A pure ethanol engine has the potential for much higher compression ratios (due to the aforementioned anti-knock characteristics, however when you have to make an engine use both pure or hybrid, the engine cannot change compression ratios other than through moderate timing changes, allowing closer to TDC for ignition compared to ignition from retarded timing before full compression is achieved). Forced induction engines can help combat this with the added ability to push more air into the cylinders and increase the ratio.

Ethanol also produces much larger amounts of ozone and formaldehyde, and is much more hygroscopic, so it will tend to readily wick water from the air, causing less combustion when allowed to sit in a tank over a long period (hence the posting on the pump above suggesting it's use for things which all tend to not be driven year round or often). A study in 2006 from the EPA, on E85 (85% ethanol blended fuel) showed that the average fuel economy across these vehicles designed to run E85, and running on that blend, compared to the same models running unleaded gasoline, resluted in over %25 WORSE fuel economy for the E85 vehicles.

[MrFunk]

Ethanol has more octane rating, meaning it will be less likely to pre-ignite, lending to the possibility of more advanced timing without knock, however from composition standpoint, it has less overall potential energy, and as such will give lower power and MPG. Specifically the same amount of ethanol has 34% lower energy than pure gasoline fuel. A pure ethanol engine has the potential for much higher compression ratios (due to the aforementioned anti-knock characteristics, however when you have to make an engine use both pure or hybrid, the engine cannot change compression ratios other than through moderate timing changes, allowing closer to TDC for ignition compared to ignition from retarded timing before full compression is achieved). Forced induction engines can help combat this with the added ability to push more air into the cylinders and increase the ratio.

Ethanol also produces much larger amounts of ozone and formaldehyde, and is much more hygroscopic, so it will tend to readily wick water from the air, causing less combustion when allowed to sit in a tank over a long period (hence the posting on the pump above suggesting it's use for things which all tend to not be driven year round or often). A study in 2006 from the EPA, on E85 (85% ethanol blended fuel) showed that the average fuel economy across these vehicles designed to run E85, and running on that blend, compared to the same models running unleaded gasoline, resluted in over %25 WORSE fuel economy for the E85 vehicles.

So the E0 (non oxy fuel) will last longer if your vehicle sits - it will be more efficient - it will burn cleaner - it may give more power - & if you can get it in a high Octane (91+) it will be less likely to pre-ignite like it's Ethonol counterpart high octane fuel.

So - from your long winded and very technical response - the non-oxy fuel is a superior product for any engine..? Especially if it's a high octane non-oxy.. correct?

[helix139]

So the E0 (non oxy fuel) will last longer if your vehicle sits - it will be more efficient - it will burn cleaner - it may give more power - & if you can get it in a high Octane (91+) it will be less likely to pre-ignite like it's Ethonol counterpart high octane fuel.

So - from your long winded and very technical response - the non-oxy fuel is a superior product for any engine..? Especially if it's a high octane non-oxy.. correct?

Nope. Ethanol can make significantly more power if your engine is specifically set up to use it and take advantage of its higher effective octane rating (Ethanol is around 110 octane I believe). Most vehicles are not set up for this, though, and thus will perform better and get better mileage on ethanol-free gasoline. It also can have a corrosive effect on fuel lines, etc. in vehicles not designed to handle it. 2 stroke engines and marine engines don't handle it well either.

[dparm]

It is superior, yes, but modern engines will run fine on E10. I certainly wouldn't pay more for E0.

For small engines (lawn mowers, boats, etc), the E10 is not preferrable.

[Chestlock]

Ethanol has more octane rating, meaning it will be less likely to pre-ignite, lending to the possibility of more advanced timing without knock, however from composition standpoint, it has less overall potential energy, and as such will give lower power and MPG. Specifically the same amount of ethanol has 34% lower energy than pure gasoline fuel. A pure ethanol engine has the potential for much higher compression ratios (due to the aforementioned anti-knock characteristics, however when you have to make an engine use both pure or hybrid, the engine cannot change compression ratios other than through moderate timing changes, allowing closer to TDC for ignition compared to ignition from retarded timing before full compression is achieved). Forced induction engines can help combat this with the added ability to push more air into the cylinders and increase the ratio.

Ethanol also produces much larger amounts of ozone and formaldehyde, and is much more hygroscopic, so it will tend to readily wick water from the air, causing less combustion when allowed to sit in a tank over a long period (hence the posting on the pump above suggesting it's use for things which all tend to not be driven year round or often). A study in 2006 from the EPA, on E85 (85% ethanol blended fuel) showed that the average fuel economy across these vehicles designed to run E85, and running on that blend, compared to the same models running unleaded gasoline, resluted in over %25 WORSE fuel economy for the E85 vehicles.

+1

Upon returning from a 7000km road trip to SoCal every spring, I'm actually happy to come back to Canada and spend $6+/gal on ethanol-free Canadian gas. Hate ethanol - feels like it kills a bit of power, not to mention that it definitely, without a doubt, kills fuel economy.

[MrFunk]

It is superior, yes, but modern engines will run fine on E10. I certainly wouldn't pay more for E0.

For small engines (lawn mowers, boats, etc), the E10 is not preferrable.

I agree that modern engines will run fine on E10 blend - but do they run better on E0? I don't see how a blend is going to burn as well as a pure even if the engine is ok with the blend just seems logic dictates the pure fuel will run better and give better performance and mileage...

[theKB]

+1

Upon returning from a 7000km road trip to SoCal every spring, I'm actually happy to come back to Canada and spend $6+/gal on ethanol-free Canadian gas. Hate ethanol - feels like it kills a bit of power, not to mention that it definitely, without a doubt, kills fuel economy.

you are running chevron 94 I would assume? Strangely enough I have done a few consecutive tanks of husky/Mohawk 94 which is an ethanol blend and found the car was smoother overall in terms of idle and power delivery. That said finding stations with husky 94 is quite the crap-shoot. I have heard a few grumblings from a certain well know tuner/shop out here that claims US 92 produces better power than Canadian 94. (our chevron 94 is without ethanol)

I have still yet to have enough time when I'm down south to go find that legendary station that has 100 on pump, getting 100 in Vancouver is not an overly simple task :-(

On an aside it would be very cool if they could tune these cars to run E85 from a power perspective but I doubt its possible.

[NWS4Guy]

I agree that modern engines will run fine on E10 blend - but do they run better on E0? I don't see how a blend is going to burn as well as a pure even if the engine is ok with the blend just seems logic dictates the pure fuel will run better and give better performance and mileage...

To echo Helix and Leo - Yes, your engine will run better on E0, how much though is debateable, and is it worth the price hike - you can answer this if you run a few tanks of each back to back and measure your mileage and "fun" factor.

[dparm]

The injectors are going to just add a bit more fuel if you're on E10.

[MrFunk]

I've noticed my exhaust tips are a little more charcoaled up than normal... E0 burn a little more dirty?

[NWS4Guy]

I've noticed my exhaust tips are a little more charcoaled up than normal... E0 burn a little more dirty?

Shouldn't - this is just a Direct Injection thing, it will soot fast no matter what.

[dparm]

Soot is a byproduct of combustion. If it's oily, then there's a problem.

[MrFunk]

Not oily at all. Yeah these exhaust tips always get sooty... Snooty car!

[jdwk]

Since ethanol contains roughly 66% of the energy that gasoline does, you can expect E10 to give you about 3% worse gas mileage and 3% less power. When we spend $400+ for an intake with a claimed 10hp gain, 3% is not insignificant.

Also, the car doesn't really have a way to know what gas you put in it. It only has O2 and knock sensors. 91 octane is 91 octane, so E10 is going to give no advantage in terms of timing advance compared to an E0 gasoline of the same octane rating. Switching between the two will also cause the fuel trims to be slightly off until the ECU readjusts using the O2 sensor readings. So if you have E0 conveniently available, I would stick to it. If not, just stick with the E10.

Unfortunately, there is no E0 in Arizona, and E85 is cost prohibitive to try to take advantage of its 105 octane rating. If I lived in a corn state, it might make more sense.

[jacobsen]

for long term? IF you can find it lol you wont be able to stick to it exclusively I don't think. Unless you only fill up there or plan out where the next e0 is.