Lower Octane Fuel + Booster = Cost Savings?

[Copper]

Hi all,

As many of you know I drive my RS6 A LOT for business and the car is just awesome for road trips. As I'm about to head out today on another 3 hour drive to see clients, I need to fill up the tank and it's $60+ for a full tank of the good stuff - 93 octane. I have the Revo Flash which is best used with 93 octane but I usually flash back to stock before a long trip.

Anyway, around here there is a decent price difference between regular 87 octane unleaded and 93 octane. Has anyone run 87 octane and put an octane booster in the tank? It costs about $3 per bottle/tank. I ran the numbers and it would save me $10-$12 per tank to do this at least.

Also, has anyone run mid-grade 89 octane wihout ill effect? What about with the ECU flash? Will it hurt the engine to try?


I'm filling up about 2-3 times a week and wow is it getting expensive!

I don't want to go buy a real business car like a 4 banger Toyota Camry or similar since I would immediately long for the RS6 and it's great power and drivability.

[DuckWingDuck]

Can't even get 93 octane here, our "premium" is 91 and I filled up for $84 the other morning But enough sniping!

I think that cars these days are smart enough to "downgrade" when it sense that the octane level isn't what it likes. Don't know about flashed vehicles though...

[rs-mad]

I pay $1.65+ AUD per litre for V-Power Racing!

[Myst]

Portugal here... one full tank is 120€... that's $181

[gjg]

Portugal here... one full tank is 120€... that's $181

Prague today, full tank Shell V-Power Racing $189.23, approx. $8.40/gallon

[RS6 POWER]

San Juan, Puerto Rico...93oct is .95cents a liter and increasing!

[Hy Octane]

The amount of commercial octane boost needed to get from 87 to 93 octane would be in gallons.. Most bottles of boost say they will increase the tank by 3 to 4 points.. this is not 87 to 91, but rather, 87 to 87.4.. see? remember, you dont get something for nothing.. Also, many octane boosters contain ingredients that can be harmful to the turbo blades which is not good.. You could use Toluene which is basically what the oil companies add to gas to raise octane, but you would still need gallons per tankful to get from 87 to 93.. If you take the risk and cause damage to the motor, it is irreversable, so do your research first.

[Spidercat]

Copper,
As you know, I have the Revo program as well on the RS6 and A4, and run the "Race Fuel" setting on the RS6 (basically max out the boost and timing within the parameters of the program) and use Torco Accelerator fuel additive. I've had no problem, knock on wood, with my car, and the boost is sickening. You can research the Torco additive (it's about $26/quart added to one tank - I use 92 octane- that's as high as we have out here). It was recommended to me by my trusted mechanic as the only viable option to maximize the revo race fuel program. He has been using this exclusively in his 1.8 TT coupe w/GT28RS turbo and a couple other mods for TWO years as his daily driver with NO problems. BTW, his TT lays down 381 BHP at the wheels! And no, he doesn't sell the additive, so I have to go down town to a machine shop to get it.
The only down side is that is turns your exhaust tips somewhat of an orange hue instead of black, but it just wipes off. I've heard "warnings" from people on a corvette forum that it probably also fouls you plugs a little bit, but nothing substanstiated. Also, most love it. Believe me, I did a lot of research before I put this into my tank first, but so far, so good.
It's not "octane" as far as I've researched, but it performs a similar function, in that it keeps your engine from knocking, which would cause the ECU to pull timing/boost and make your car go limp to save the engine. Anyway, got to get back to work, but if you're interested I could scan the lable off the can, although google I'm sure has this info. It cost me about $90-$100 a fill up, but it's worth it.

[Spidercat]

Sorry Copper, looking back at your original question, I didn't much answer it! I was in a rush and feel like a bit of a retard. Re: Lower octane fuel + Octane boost = cost savings I'd say no. I have to agree HyOctane. Those "octane booster" shots and stuff at Pep Boys' don't really work, IMHO. The Torco stuff added to 87 Octane may work effectively, but unless you can get it way cheaper than $26/tank, I'm sure it's cost-prohibitive.

[Skaala]

Octane numbers Supermarket (95) vs Shell optimax (98) vs BP ultimate (97)
http://www.youtube.com/watch?v=0QGCYLwTCGI


octane boosters?
http://www.youtube.com/watch?v=iIE_x3HQd_w

[AuditudeA642]

Hey. im Auditudes son. I wouldn't never run low octane fuel on that engine, you could really screw up the engine. This is what i would recommend, lease a 2008 A4 2.0T Quattro (audi only wants 229 a month for a lease for the special edition). I have a A4 2.0T with a chip and alot of other stuff and get 28mpg city driving, some get around 35 or 36 on the parkway. Its your best bet, its still an Audi, some new technology, quick if you do a 91 octane chip from apr and you save alot of money on gas.

[DuckWingDuck]

Well, cars nowadays are intelligent enough to tune down if you put in a lower octane (after all, it's only intuitive since it's able to tune up with a higher octane). Of course, not advised but in my opinion, may be an option.

[rs-mad]

Damage to the engine is unlikely but degraded perfomance is, having said that I base that comment on a tune that doesnt disable or reduce the amount of correction the ecu can do to prevent knock.

From what I have seen Revo, APR and GIAC in varying ways limit the computer control over the safety measures to allow the performance they claim. I wont say which but one of those brands lock the EGT's on their tunes to 550 Deg C and irrespective of the RPM or Load that value doesnt chang, anything under 900 is safe but with such methods you would never know and worst nor would the ECU

[DuckWingDuck]

Damage to the engine is unlikely but degraded perfomance is, having said that I base that comment on a tune that doesnt disable or reduce the amount of correction the ecu can do to prevent knock.

I'm slightly confused... you're claiming that no damage will be done on a lower octane fuel even with an ecu that doesn't disable or reduce the amount of correction? So then it should be perfectly safe (not talking about performance) to run lower octane on a regular ecu that will?

From what I have seen Revo, APR and GIAC in varying ways limit the computer control over the safety measures to allow the performance they claim. I wont say which but one of those brands lock the EGT's on their tunes to 550 Deg C and irrespective of the RPM or Load that value doesnt chang, anything under 900 is safe but with such methods you would never know and worst nor would the ECU

That's like the high school cheerleader who'll let you feel her up but brushes you away when you go to unzip her trouser. We are none of us here overly biased, we're all regular blokes trying to help each other out so if you know something that would help make the rest of us more knowledgeable, why not share it?

[rs-mad]

I'm slightly confused... you're claiming that no damage will be done on a lower octane fuel even with an ecu that doesn't disable or reduce the amount of correction? So then it should be perfectly safe (not talking about performance) to run lower octane on a regular ecu that will?


That's like the high school cheerleader who'll let you feel her up but brushes you away when you go to unzip her trouser. We are none of us here overly biased, we're all regular blokes trying to help each other out so if you know something that would help make the rest of us more knowledgeable, why not share it?

Yes correct but the ecu can also only retard so much so I am not willing to say how low the octane can be without alot of testing....I run mine on a strict diet of V-Power Racing and soon Race Fuel when I setup the nitrous.

APR was the brand but it may have been a one off.......?

[Copper]

What an great board!


Anyway, back from my business trip and I ran Revo Program #2 which is approx 500 or so HP with mid-grade 89 octane for a full 652 miles on 1 1/2 tanks of gas. No issues at all. 90% highway speeds and 70-80MPH. Computer is telling me 19.8MPG average. I reset it before the trip.

I didn't get any knocking or other issues. I also didn't race anyone or really put the turbos through the paces.

Next trip I'll put the ECU back to stock and run 89 fuel to see if there are any issues and what the MPG will be.

Around town I run the good stuff and keep the Revo program active.

I think basically everyone is correct that 93 is the best bet and anything less is a little risky. Seeing the prices in other areas of the country/world makes me feel much better....