Does anyone have a dyno of 91 vs (93/94) octane fuels?

[doverosx]

Hello all,

I'm currently running 94 octane (93 octane + 10% ethanol); with my last car, I took 4 years of fill-ups and economy measurements recorded with fuelly and observed approximately 5% better MPGs with 94 octane. I'm hoping for more concrete evidence (Knock retard logs or dynos) that will definitively show some evidence of the stock ECU tuning on a stock car. If that isn't available already, I do have Torque (APP for reading OBD2 on phone) and an OBD2 reader. I can certainly run some logs...hopefully there is a knock retard value. I had to go by the timing advance (provided by VVT signals on the Spec-V.

Please refrain from turning this into a discussion of "that isn't what octane means", "ethanol is good/bad" because there are just way too many already to list and the SRT/petrochemical engineers have already done that homework for us.

Thank you!

[Tweak]

I know one member (zyxelenator) has been toying with E85, maybe he can offer some useful information.

[zyxelenator]

I can't really provide any logs at the moment. Since I'm not at home and not driving my 500t. But per butt dyno 3 gallons of E-85 in tank felt better without AFRs going crazy( per Torque app).

[moosestang]

why do you think you are running 94 octane? if the pump says 93, then that is what the octane rating is including the ethanol. You'd get better performance, mpg and less chance of knock with ethanol free 93 octane, if you can find it.

[doverosx]

I can't really provide any logs at the moment. Since I'm not at home and not driving my 500t. But per butt dyno 3 gallons of E-85 in tank felt better without AFRs going crazy( per Torque app).

Ahhhh, perhaps you can lend some insight into whether the Toque app shows a knock retard value; I know that Subaru's have one which is perfect for "this octane vs that octane in this weather" type of comparos. You know...I guess I can go check myself - perhaps after GT6 this evening.

[doverosx]

why do you think you are running 94 octane? if the pump says 93, then that is what the octane rating is including the ethanol. You'd get better performance, mpg and less chance of knock with ethanol free 93 octane, if you can find it.

I know I'm running 94 octane because Petro Canada sells 93 octane + 10% ethanol up in Canuckistan (except for some locations in Quebec which are straight up 94 octane with NO ethanol).

Fueling options are 91 without ethanol, 91 with ethanol OR 94 (w/10% ethanol) where I live. I'm really just looking for conclusive evidence on a purely stock basis or maybe a lightly modified basis.

[moosestang]

I know I'm running 94 octane because Petro Canada sells 93 octane + 10% ethanol up in Canuckistan (except for some locations in Quebec which are straight up 94 octane with NO ethanol).

Fueling options are 91 without ethanol, 91 with ethanol OR 94 (w/10% ethanol) where I live. I'm really just looking for conclusive evidence on a purely stock basis or maybe a lightly modified basis.

Well I don't know how they rate the fuel in Canada, but in the US, 93 octane with 10% ethanol is still 93 octane. If you can get 93 or 94 octane ethanol free gas, then that is better than anything with ethanol. ethanol in gas is crap, unless you are running e-85 to make big power.

Oh, i don't need a dyno to know that you aren't going to see any significant gains by running 93 vs 91, unless you have a tune specifically for 93.

[slowbird]

The way Doverosx is explaining it sounds confusing. But up here we have 91. 91 without Ethanol. 93 w/ethanol and Petro Canada gas stations sell what they call Ultra 94 which is 94 Octane with ethanol.

Doverosx, like Moosetang says, if you're filling up with 93 octane. The octane rating is 93 whether there is Ethanol in it or not. You're only running 94 Octane if you're filling up with Ultra 94.

For your original question Dover, a member has done Dyno runs with different ECU/Piggyback setups and has tried using Octane with waaaay higher rating than 94 and it made no difference.

Between 94 and 91 there won't be any noticeable difference. You may notice better fuel economy using the Shell V-Power fuel as it is Ethanol free. There are some studies that show Ethanol decreases fuel economy.

[doverosx]

The way Doverosx is explaining it sounds confusing. But up here we have 91. 91 without Ethanol. 93 w/ethanol and Petro Canada gas stations sell what they call Ultra 94 which is 94 Octane with ethanol.

Doverosx, like Moosetang says, if you're filling up with 93 octane. The octane rating is 93 whether there is Ethanol in it or not. You're only running 94 Octane if you're filling up with Ultra 94.

For your original question Dover, a member has done Dyno runs with different ECU/Piggyback setups and has tried using Octane with waaaay higher rating than 94 and it made no difference.

Between 94 and 91 there won't be any noticeable difference. You may notice better fuel economy using the Shell V-Power fuel as it is Ethanol free. There are some studies that show Ethanol decreases fuel economy.

Thanks guys and I admit the way I was explaining it was horrible. Our 94 is *only* with 10% ethanol and is a custom blend of 93 octane with the added ethanol to boost it up 1 octane point; at least this is what e-mailing them yields as a response from "petrochem. eng."

I'll do one more fill-up of 94 to ensure that the 87 octane that Peel filled up with is removed successfully. I'll check tomorrow what sort of logging I can expect from Torque and determine what sort of stuff I can expect from my "tests".

[slowbird]

Ugh. Peel Chrysler on Lakeshore?

Don't go there. They are awful. It's worth the drive to Gerogetown Chrysler for service. They don't hassle you for service packages and they don't stress me about waranty repairs.

[doverosx]

Ugh. Peel Chrysler on Lakeshore?

Don't go there. They are awful. It's worth the drive to Gerogetown Chrysler for service. They don't hassle you for service packages and they don't stress me about waranty repairs.

That's the one! Good to deal with for the sale, but I'm in Ottawa so I won't be going out of my way to go there for service. Thanks for the tip on Georgetown, I'll check it out of Ottawa dealers end up being stingy.