What Octane to use???

[Sssnake08]

I have a gas station by me that sells all kinds of high octane fuels. My plan is to add 1 gallon of high octane every time I fill my tank with 93 octane. Choices are 98, 100, 104, 108, 110, and 116. Which one do you guys think I should use? Thanks for the help.

[Tommy Gun]

Alloy Dave will say it is wasteful to do such a thing. :look:

I do it at the track for insurance, usually 100 octane.

[Joe G]

Alloy Dave will say it is wasteful to do such a thing. :look:
.Me too. :shades:


But it's ok to add a little just to make sure you have enough octane (ie: your not sure if the 93 is of good quality or if it takes 3 months to go through a tank of gas). Running higher than needed octane doesn't do anything (ie: more power) and can actually hurt performance (higher octane gas is harder to combust, so if it's too high you can actually have a poor running engine).


JMO...

[Tommy Gun]

Interesting...

[Sssnake08]

Not really looking for more power out of the deal, just to try to compensate for the 10 percent ethanol crap we use here in the state of NY.

[Joe G]

Not really looking for more power out of the deal, just to try to compensate for the 10 percent ethanol crap we use here in the state of NY.If that's the case, then try the Sta-bil Ethanol treatment stuff that TG and Dan have been posting about in a different thread.

[bigb427]

... just to try to compensate for the 10 percent ethanol crap we use here in the state of NY.

No reason to. Your car automatically compensates for the ethanol. If your car is running ok and you don't have a check engine lamp on, then there is nothing to worry about.

[Joe G]

If that's the case, then try the Sta-bil Ethanol treatment stuff that TG and Dan have been posting about in a different thread.

See these posts...


I did some searching and Red Sta-bil is good to go!!

http://www.sta-bil.com.au/sta-bil_faq.html


http://www.onecrazydog.com/pictures/image-cache/More_Stuff/stabil_disp1024.jpg


Just to expand on the whole Stabil thing ...because it is widely misunderstood and might not do what you think...

Red Stabil is optimized to just prevent gum/varnishes from forming when gas is stored for up to 6 months. However, if E10 gas separates, nothing can chemicaly reintegrate the water that falls out of solution and that will sink to the bottom of the tank and will be immediately sucked-up by the pump. The good news is that if an engine starts, separation has not occured, tho octane might have degraded. The bad news is that if it did separate and you attempt to start the engine, extensive damage to fuel system components (especially injectors and pumps) can quickly result. The Marine (blue) Stabil is optimized to help mitigate water separation of Ethanol-blend gasolines by chemically absorbing some amount of water. It also contains the gum/varnish stabilizers of red Stabil (just more) and also adds moisture corrosion prevention. There's also a yellow Ethanol Stabil with gum/varnish fighters and mositure corrosion fighters but not clear to me how much water, if any, it can actually 'absorb.' My sense is that it's between red (regular) and blue (Marine) Stabil ...if you presenetly use red stabil as your small engine gas treatment and your gas has ethanol (virtually everywhere now), the yellow Stabil should be your new default (not red).

Blue (Marine) stabil is probably the best for long term/winter storage of e-blends in a modern sealed automotive gas tank since it includes gum/varnish stabilizers, moisture damage prevention *and* enhanced water absorbtion. However, even blue/Marine stabil cannot prevent poorly stored E-blend gas from separating because gas exposed to air can absorb way more water than even blue (Marine) Stabil can hold in suspension.

Regardless of stabilizer additive, gas will degrade in octane (Stabil does not address octane loss) when it sits however the rate of octane degredation can vary widely. The bad news is that in an unsealed container with exposure to atmoshperic air or vent-breathing, octane can degrade rapidly -- up to about 1%/week which would render 93 pump gas to 75 octane in 5 months. Clearly this can have dire consequences if a car without knock-sensors ('07-'10 GT500) is run hard on degraged octane fuel. On the bright side, in a totally sealed container with little or no air circulation/contact it might only lose a 2-3 points in the same 5 months. The good news is that modern emissions standards require very tight venting standards (vapor purge test is performed every run cycle), so that if your car is put away for winter with a full tank (with or without Stabil, but preferably with) it will likely only lose a few points.

After long storage (with or without Stabil) my suggestion would be to drive the first tank easy (no WOT without knock sensors!) and then refill with 93 (and no WOT for the first 5 miles to purge lines/rails). Alternatively, you could run it for 50 miles and top off with a few gallons of 100+ octane aviation gas if available locally (some gas stations even sell 100 octane in some areas). Alternatively, you could also add some Torco, but it does tend to coat plugs, etc. Paint thinner (Toluene) can also be added and is considered an excellent octane booster when available economically from a paint-supply house (you can do some searches for octane-targeting mixing recommendations (http://www.elektro.com/~audi/toluene/)if interested).

Anyhow, to summarize, just wanted to separate several different considerations as I understand them:
=> Standard (red) Stabil ...gum/varnish prevention intended for non E-blend gas for up to 6 months
=> Ethanol (yellow) Stabil ...same as red for gum/varnish, helps prevent moisture corrosion moisture (not separation!)
=> Marine (blue) Stabil ...same as yellow for gum/varnish and moisture corrosion prevention but also adds chemical water absorbers (but can't compensate for poor storage) and is used religiously in marine applications. THIS IS LIKELY THE BEST CHOICE FOR RELIABLY OVER-WINTERING SEALED-TANK E-BLEND FUELS.
=> NONE of the Stabil products do anything to boost/preserve octane per se
=> Storage container is all-important -- especially for E-blends. Fotunately, newer car tanks are quite good in this regard
=> Separated gas (water separation from atmospheric moisture or ethanol disolution) *cannot* be recoverd/restored and must be purged ...if starting was attempted and failed, likelihood of damage is high (e.g. injectors, pumps).

This is a confusing topic but the above sums up my understanding.

[dwattsup]

I wouldn't recommend buying the higher octane at the pump. Who knows how long it's been sitting in the tank and unless it's airtight it will loose octane over time. Especially if you're running a tune that requires higher octane. My high octane comes from my shop out of a sealed 50 gallon drum that gets emptied on a regular basis.

[Sssnake08]

I wouldn't recommend buying the higher octane at the pump. Who knows how long it's been sitting in the tank and unless it's airtight it will loose octane over time. Especially if you're running a tune that requires higher octane. My high octane comes from my shop out of a sealed 50 gallon drum that gets emptied on a regular basis.

No- my tune is for 93 octane, nothing higher

[dwattsup]

No- my tune is for 93 octane, nothing higher

Even so, if you're paying more to get a higher octane rating and it's been sitting in an unsealed tank for a while, then you're not getting your money's worth and not solving the problem you're trying to solve. If you know they sell a lot of whatever octane you're buying that's better. But how do you know for sure?

[68fastback]

Not really looking for more power out of the deal, just to try to compensate for the 10 percent ethanol crap we use here in the state of NY.

Ethanol actually has a higher octane (about 110) than normal gasoline. It's a little game why it's in gas (aside from the farmer subsidy games and bogus 'green' game, etc) ...it substitutes for some clean-burn additives that had to be removed when they were found to be harmfull but, more importantly to the oil compenies, it adds octane for less $$ than refining gas further. A match made in heaven :devil: -lol.

But it comes at a price. Aside from octane (since once ethanol is blended-in it's now at the stated octane: 87, 91, 93, etc) and the risk of damage to injectors and other components from potential ethanol separation (Stabil marine/blue can help with that), ethanol contains only 70% of the energy of stright gasoline, so a 10% blend of ethanol reduces the energy in the gas by about 3% (10% of 30%). So you're paying the same price for E10 but you're getting 3% less miles on every gallon.

So, no need to blend in higher octane to compensate for ethanol octane-wise and there's no way to compensate for the 3% lost energy since that's not an octane issue.

However, if you're running an aggressive tune (timing) and want some octane anti-knock buffer on '07-'10 (no knock sensors) then yon can blend in some 100 octane (one gallon in 14 gallons of 93 bring you to about 93.5), no problem ...but none of that has anythng to do with ethanol.


No reason to. Your car automatically compensates for the ethanol. If your car is running ok and you don't have a check engine lamp on, then there is nothing to worry about.

+1 ..exactly.

[Sssnake08]

Ethanol actually has a higher octane (about 110) than normal gasoline. It's a little game why it's in gas (aside from the farmer subsidy games and bogus 'green' game, etc) ...it substitutes for some clean-burn additives that had to be removed when they were found to be harmfull but, more importantly to the oil compenies, it adds octane for less $$ than refining gas further. A match made in heaven :devil: -lol.

But it comes at a price. Aside from octane (since once ethanol is blended-in it's now at the stated octane: 87, 91, 93, etc) and the risk of damage to injectors and other components from potential ethanol separation (Stabil marine/blue can help with that), ethanol contains only 70% of the energy of stright gasoline, so a 10% blend of ethanol reduces the energy in the gas by about 3% (10% of 30%). So you're paying the same price for E10 but you're getting 3% less miles on every gallon.

So, no need to blend in higher octane to compensate for ethanol octane-wise and there's no way to compensate for the 3% lost energy since that's not an octane issue.

However, if you're running an aggressive tune (timing) and want some octane anti-knock buffer on '07-'10 (no knock sensors) then yon can blend in some 100 octane (one gallon in 14 gallons of 93 bring you to about 93.5), no problem ...but none of that has anythng to do with ethanol.



+1 ..exactly.

thanks Dan, guess I'll use the 100 octane then- probably just being over protective of the car, but for an extra couple of bucks a month I'll take the piece of mind. I feel pretty confident about the high octane gas not sitting around very long- There's quite a few motorsports tracks in this area- both automobile and recreational vehicles

[68fastback]

thanks Dan, guess I'll use the 100 octane then- probably just being over protective of the car, but for an extra couple of bucks a month I'll take the piece of mind. I feel pretty confident about the high octane gas not sitting around very long- There's quite a few motorsports tracks in this area- both automobile and recreational vehicles

...yeah, can't hurt, Charlie.

I do the same thing in winter when the Ranger sits quite a bit ...blending in some premium just because I know the octane is slowly degrading (and the Ranger can probably run on 80 octane -lol) ...same for my generator since generators run as hard as racecars so are much more octane sensitive and knock at high load will toast a generator instantly ...same as a hi-po car at WOT.

---

My biggest over-wintering fear tho is ethanol separation, but in a well-sealed automotive gas tank should not be a problem since no additional moisture can get in and at 10% ethanol it should remain stable (imo, the new 15% standard being pimped is really pushing the limits of how much 'water/alcohol' gas can reliaibly 'hold' in suspension). For the generator (which does have a breather in the cap and is stored in unheated space) I've had no separation problems even for up to a year using Stabil.

I use Stabil red in the tractor, snow-blower and chain saws (just for anti-gum/varnish purposes since they're all drained and run-dry before storage), but I use Stabil blue (marine) in the generator since that's primarily a ehtanol separation concern.

[Sssnake08]

...yeah, can't hurt, Charlie.

I do the same thing in winter when the Ranger sits quite a bit ...blending in some premium just because I know the octane is slowly degrading (and the Ranger can probably run on 80 octane -lol) ...same for my generator since generators run as hard as racecars so are much more octane sensitive and knock at high load will toast a generator instantly ...same as a hi-po car at WOT.

---

My biggest over-wintering fear tho is ethanol separation, but in a well-sealed automotive gas tank should not be a problem since no additional moisture can get in and at 10% ethanol it should remain stable (imo, the new 15% standard being pimped is really pushing the limits of how much 'water/alcohol' gas can reliaibly 'hold' in suspension). For the generator (which does have a breather in the cap and is stored in unheated space) I've had no separation problems even for up to a year using Stabil.

I use Stabil red in the tractor, snow-blower and chain saws (just for anti-gum/varnish purposes since they're all drained and run-dry before storage), but I use Stabil blue (marine) in the generator since that's primarily a ehtanol separation concern.

Thanks for sharing your considerable knowledge Dan...looking forward to seeing everyone at Orfstock next month. I haven't been on here too much lately- I finally got moved into my house and its been occupying most of my time...In terms of generators...I have natural gas where I am and was going to put in a natural gas generator to avoid that headache.

[Gr8snkbite]

Thanks for sharing your considerable knowledge Dan...looking forward to seeing everyone at Orfstock next month. I haven't been on here too much lately- I finally got moved into my house and its been occupying most of my time...In terms of generators...I have natural gas where I am and was going to put in a natural gas generator to avoid that headache.


Not yet confirmed...

[68fastback]

Hopefully folks plans will firm-up soon so Greg can see where everything stands and let us know a tentative agenda. It's a little bit of chicken and egg, unfortunately.

[68fastback]

Thanks for sharing your considerable knowledge Dan...looking forward to seeing everyone at Orfstock next month. I haven't been on here too much lately- I finally got moved into my house and its been occupying most of my time...In terms of generators...I have natural gas where I am and was going to put in a natural gas generator to avoid that headache.

Yeah, that would be great!! ...wish we had natural gas here ...besides it being so much cheaper these days it'd be great to have a Generac Guardian natural gas gen-set with no gasoline hassels. Before Hurricane Irene hit we filled up the Ranger and the Fusion and two 6-gal cans ...about 45 gallons, but that's only about 22 days of 'survival' and losts of folks were without power for several weeks (we were only out for 9-10 days).

Look forward to seeing you at Orfstock, Charlie ...hopefully we'll have enough critical mass to pull it off :banana: ...and hope George or Jim have their '13 by then :drool: ;-)

[hellfyr]

Run it on 87 and report back.... :tiptoe2:

[Sssnake08]

Run it on 87 and report back.... :tiptoe2:

:gun::boink:

[Tommy Gun]

:ohsnap:

[hellfyr]

LOL... nothing meant by that...

Was just throwing in an equivalent $.02
Without knowing the purpose for the car nor your driving habits, speculating on what octane should be run is pointless and purely personal preference.

If you do nothing but daily drive it, 91/2/3 will be plenty and the stock tune (or even a safe modified tune) should adapt enough to cover the differences.
If you are regularly pounding your right foot through the floorboard, and/or tuned on the ragged edge for maximum power, then yeah... you need to bump up the fuel octane to maintain a safe ignition point and deter detonation.

My own preference instead of mixing fuels is to use a fuel catalyst to bump the octane up.
Skip the crap off the shelf, and order Torco instead.
As a very conservative estimate:
15 gallons of 93 + 16oz (1/2 can) of Torco Accelerator nets you 95 octane equivalence
15 gallons of 93 + a full can (32 oz) of Torco nets around 96.5
15 gallons of 91 + 16oz Torco gets you to 93
15 gallons of 91 + 32oz Torco gets you to 94.5

Torco sells for around $20/32oz so it isn't cheap, but it is always available in the can even when a pump with race fuel is nowhere to be found.

**Edit**
I should add to be careful when ordering Torco ... They now produce a Diesel fuel catalyst as well.

Rod

[Sssnake08]

There was no offense taken, just having fun with you

[Tommy Gun]

I quit using Torco in the track car, it messes up the plugs too quickly. :look:

[hellfyr]

You just don't like orange...

[Alloy Dave]

Ethanol actually has a higher octane (about 110) than normal gasoline. It's a little game why it's in gas (aside from the farmer subsidy games and bogus 'green' game, etc) ...it substitutes for some clean-burn additives that had to be removed when they were found to be harmfull but, more importantly to the oil compenies, it adds octane for less $$ than refining gas further. A match made in heaven :devil: -lol.

But it comes at a price. Aside from octane (since once ethanol is blended-in it's now at the stated octane: 87, 91, 93, etc) and the risk of damage to injectors and other components from potential ethanol separation (Stabil marine/blue can help with that), ethanol contains only 70% of the energy of stright gasoline, so a 10% blend of ethanol reduces the energy in the gas by about 3% (10% of 30%). So you're paying the same price for E10 but you're getting 3% less miles on every gallon.

So, no need to blend in higher octane to compensate for ethanol octane-wise and there's no way to compensate for the 3% lost energy since that's not an octane issue.

However, if you're running an aggressive tune (timing) and want some octane anti-knock buffer on '07-'10 (no knock sensors) then yon can blend in some 100 octane (one gallon in 14 gallons of 93 bring you to about 93.5), no problem ...but none of that has anythng to do with ethanol.



+1 ..exactly.+1...all of it...except as TG knows I wouldn't even add the 100 octane. :lol: