Going state side - the gas debate

[nelsonmxmarc]

So with a few trips coming up early this spring - Montreal to Florida / and Montreal to Deals Gap at the Dragon in NC.

There's been a number of debates on what GAS to use, and which company is reputable for keeping proper octane ratings.

My only reason for this is because my car is tuned on 94 octane which is readily available in Quebec via Petro-canada. As of early last year, they relieved the 10% ethanol rating and have made their 94, an ACTUAL 94 (Ethanol is alcohol, and lowers octane rating as a competing chemical in the mix).

So my question is this;
What's a good gas station STATE Side that offers high quality supreme fuel?

Something that will NOT require octane booster to bump ratings..
Besides the obvious lower MPG due to added ethanol, i want to avoid detonation as best as possible..

[Terrh]

all of them. I mean stay away from obviously **** stations but 99% of the gas you'll buy there is better than the stuff you can get here.

american 93 is WAY better than canadian 91 or 94.

are you going to the gap for ZDAYZ?

We should convoy. I've been to the gap twice in my GTR, florida once, northern MI twice and never had an octane problem. In fact according to the TECHTOM display I had, my (chipped) ECU would run up to 32* advance at full throttle, compared to 25-26* on canadian 91. the further south I went the happier the car got.

[nelsonmxmarc]

all of them.

american 93 is WAY better than canadian 91 or 94.

See, i've heard contradicting stories on this.. A lot of people are telling me they're 10% ethanol 90% of the time. 10% lowers ratings 2-3 points which is total buzzkill..

Do you know what company's offer 93? I've never seen 93 state-side, but again, i've never really looked..

Thanks man

[M13]

wth are you talking about? ethanol has a higher octane rating than gasoline...

it just has less energy/volume which is negligible for a street car.

[nelsonmxmarc]

See yea, i was under the impression 200 proof or wtv used, can yield an octane rating of ~100 on its own, but I also assumed that when ethanol was mixed with pure gasoline that it became less volatile, thus 'Lower octane' theoretically. Burning becomes subsequently less efficient, which is where the obvious drop in mpg is seen, but also can lead to detonation due to inconsistency?

[M13]

less volatile = higher octane.

the reduced MPG is due to lower energy/mol. You need to use less assumptions based on self-theories but just look at the facts. efficiency? detonation due to inconsistency? WHAT?

Ethanol has higher octane (resist auto-detonation) but doesn't have as much power/mass compared to gasoline. Ethanol also has a lower AFR than gasoline. This is why guys who use E85 have large injectors to make up the extra volume for fuel.

no disrespect, but I just could not believe what I was hearing LOL.

[DreadedFist]

I;ve said this before, and I'll say it again. Get a moderately aggressive 91 octane tune, but run 94 all the time. This way, when you're somewhere that doesn't have 94, you can still run 91. Like in the states, for example. You can still make good power on 91 octane tunes, just look at California. They have no higher than 91 octane available at the pump, yet because of their tuning practices, they can still run significant boost and make good power, even without meth.

Edit: But it's worth mentioning that ethanol increases octane rating. The downside is that it doesn't have the same amount of energy as gasoline in equal quantities, hence why you see guys running E85 also running huge fuckoff injectors and fuel pump setups. The difference that 10% ethanol makes, however, is negligible.

[nelsonmxmarc]

Yes, i'm sorry i wasn't raised in a lab that studied the effects of gas/ethanol concentration - i'm pretty sure 99% of opinions/questions are self-generated theories, Mike; but of course you know this, because you know everything? lol..

Anyways besides the sarcastic remarks, i have to disagree.

Yes reduction of mpg is due to the lower energy/mol - it requires more fuel with the added ethanol to burn as effectively (Generate the same heat) as pure gasoline.

Because E10 elevates octane levels, 91 octane for instance, with a 10% ethanol blend has a base-rate value of ~88/89 octane based on pure gasoline, before the additive. This means the true value or octane rating of gasoline prior to mixture is only 88/89. The fuel being burnt is going to mimic 91 octane with the introduction of ethanol. Thus why i said, the theoretical 'lower octane'.

Yes, your right there, and that's my mistake - Higher octane is lower volatility.

The only thing to take into account before analyzing volatility is flashpoint. It takes more heat to ignite pure gasoline than it does to ignite ethanol. Preignition occurs in E10/E85 vehicles due to this. Cylinder bore temperatures are too hot, pre-igniting the ethanol or ethanol mixed gasoline (flashpoint ~16 degrees), whereas conventional gas is in the area of -45 celsius - requiring a spark every time; less chance of preignition. Preignition can lead to knock (detonation), due to when unburnt or prematurely burnt fuel outside of the flame envelope is burnt. Thus, adding ethanol gasoline DOES raise octane levels in theory by making gas more effectively 'slow burning', but, it doesn't account for one thing....

Where Ethanol fails is to produce heat energy equivalent to pure gasoline of the same grade. Comparing conventional gasoline and ethanol blends (E10/E85), the BTU/LB HHV and LHV is a HUGE difference.

This can go on forever, and i'm sure there are dozens of biased opinions online. Obviously the chemistry can sway in either direction, but E10 for this particular application isn't ideal since pure gasoline burns hotter (producing more energy), more effectively and efficiently than gasoline with ethanol additives..

Basically what i'm getting at is, i'd rather run 100% pure gasoline than E10 in any case.

[nelsonmxmarc]

all of them. I mean stay away from obviously **** stations but 99% of the gas you'll buy there is better than the stuff you can get here.

american 93 is WAY better than canadian 91 or 94.

are you going to the gap for ZDAYZ?

We should convoy. I've been to the gap twice in my GTR, florida once, northern MI twice and never had an octane problem. In fact according to the TECHTOM display I had, my (chipped) ECU would run up to 32* advance at full throttle, compared to 25-26* on canadian 91. the further south I went the happier the car got.

Yup, i'll be there for zdayz! I'm down for that, absolutely.

[M13]

having run both pure 94 octane (chevron in BC) and 94 octane E10 (husky/mohawk), detonation counts were similar in both runs on dyno.

keep in mind flash point ratings are for 1atm. Inside a compressed cylinder during compression stroke, the flash point raises in temp.

I could go on w/ my 40 credits of University chemistry knowledge, but honestly for street cars, the difference is so little it doesn't matter really. Just choose what you think runs well on your car.

Some people swear by E10 94 and offer very good reasons and rationality to why (ie: Jon aka Dragon_Humper). To me, his 2 cents have more weight than those who just swear by Chevron 94 saying, "it's good ****, I don't know how it works, but it's good **** LOL". Also, I like the fact that Jon's monster backs his words up on his theories where as the latter drive bolt-on GTS/GTR.

[sykline]

M13 speaks the truth.

[Ricky Ricer]

Stay away from places such as Bradleys, Diamond Shamrock, Safeway, King Soopers/Kroger. Kind of hard to recommend where to go to since so many states have different gas stations. The big ones that are everywhere are Shell, Conoco, BP. I would try my hardest to use those three. My favorite is Shell, proven to be better by many automotive media tests. I only used Shell until I got tuned on E85.

[nelsonmxmarc]

Perfect that's what I was looking for. Last pass I made south was in my truck so I didn't really pay much attention to the brand, all I could tell was my mpg was dirt poor.
Shell is great here too, so I'll keep an eye out!
Thanks for the heads up

[needavdub]

I run Shell 93 octane "V-power" in all my performance cars, it's easy to find in every state and it's always been very consistent for me. As for the 10% ethanol stuff, here in Michigan they have to label the pumps very clearly stating if there's any ethanol in the gas and if so what %age. All the Shell's I've ever been to in multiple states have 0% ethanol so I think it would be a safe bet. Amoco (available at BPs) is also very good, and I have a few friends that swear by Mobil, the biggest thing is just make sure you go to bigger higher traffic stations (Anything right off the hiway). Some smaller stations in po-dunk towns fill their in-ground tanks with whatever they get cheapest regardless of what brand is on their sign.