Gasoline Octane?

[Don Hiltz]

Lately, there have been several articles in the automotive section of various newspapers concerning octane. It was stressed that we frequently pay for more octane that our cars really need. Their rule of thumb was that if your car doesn't knock with a lower octane, you're wasting money buying more than you need.

Personally, I've always used 93 octane, but with the escalating price of gasoline I'm beginning to wonder.

Has anyone ever used mid grade (87 octane)? Was there a noticeable difference?

Don

 

[adamlotus]

i would not recomend using anything under 91 octane.

 

[SidewinderGTS]

I used 94 all of last year and switched to 91 this year.Car still runs awesome.

 

[plumcrazy]

how much do you think you're gonna save driving your viper ???

you most likely dont put that many miles on it to begin with. $ / mile saved cant be worth the risk. its cheap insurance.

 

[Racer Robbie]

We have 93 octane here in CT that is blended with 10% alcohol. Ct uses alcohol as an octane booster. I have to run octane booster as the car pings without it. The problem is caused by what is called phase separation of the gas while sitting in the retailer's storage tanks. The alcohol and the water it attracts separates and then falls to the bottom of their storage tank leaving low octane fuel behind. Check out this web site for more information on this problem.

http://www.starbrite.com/productdet...nd Diesel Additives&ProductSSCat=Startron Gas

Robbie

 

[YellowViperSRT10]

Come on, use the highest octane you can get. Of course that does not mean drive your car on 100 octane all the time if you can find it. No one buys a Viper and worry's about gas mileage. We all want performance, and using mid grade will effect performance. Not worth it for a few cents a gallon savings.

 

[V10SpeedLuvr]

Yes, gas prices **** and yes, I'd like to save money, but not at the risk of running anything less than 93. I'm going to FL for Memorial Day and I bet prices will be AT LEAST $3.50+/gal for premium


Gas prices have slipped a little bit in GA lately, premium is just under $3/gal for now

 

[Joseph Dell]

Gas prices have slipped a little bit in GA lately, premium is just under $3/gal for now

Maybe in the country... Atlanta is 3.2x most places for premium. and that's at QT!

JD

 

[V10SpeedLuvr]

Maybe in the country... Atlanta is 3.2x most places for premium. and that's at QT!

JD

I noticed that this weekend. We paid $3.20 for premium right below Forsyth. But in Macon, its $2.98 at places like RaceTrac. The bigger names (BP, Exxon, etc) are closer to the $3.20 range. And hey, this isn't the country, its hell!

 

[Racer Robbie]

I have seen $3.65 here at Mobil / Exxon in CT

 

[viperbilliam]

The manufacturer in your owners manual tells you what you need; it's probably 91 as it is in mine. You are wasting your money if you use a higher octane than that unless you have modified the engine such as increasing the compression and/or the timing. Using less than 91 isn't good either and decreased performance will result because the knock sensors will back off the timing.

 

[SilverViperSRT]

For a 2004 they recommand 93, maybe it's because we don't have knock sensor.

 

[Tom F&L GoR]

http://forums.viperclub.org/showthread.php?t=601253&highlight=octane+appetite

http://forums.viperclub.org/showthread.php?t=596986&highlight=octane+appetite

http://forums.viperclub.org/showthread.php?t=575257&highlight=octane+appetite

http://forums.viperclub.org/showthread.php?t=570325&highlight=octane+appetite

 

[Matrix]

Here in Germany you can get 4 different octane fuels, 91octane, 95octane, 98octane and 100 octane.

The prices for 91 octane are round about 6,01$ per gallon
95 octane 6,15$ per gallon
98 octane 6,71$ per gallon
100 octane 7,05$ per gallon


Don´t worry, be happy with your fuel prices...

 

[Mike Dolan]

In my opinion it works this way: If you have a later Viper, it's equipped with knock sensors, so your engine is probably safe. However, the way this works is by detecting knock, it then retards ignition timing, which reduces power and effienciency, resulting in reduced mileage.

So you will save a bit on the cost of fuel, but you'll use more of it, so there's little to no actual savings.

Just my opinion,
Mike Dolan

 

[Tom F&L GoR]

Mike, that's right... but not.

Yes, the system detects knock and quickly (and slightly) retards the timing. However, it would only do this at the most stressful conditions like open throttle. Your engine is not at imminent knock conditions when cruising down the highway, so the spark retard would not happen. When you are driving in a manner to obtain good fuel economy, it will not hurt. Your fuel economy under high power conditions might suffer slightly.

 

[Racer Robbie]

To clarify a point made in an earlier post 2003-2004 SRT vipers require a minimum of 93 octane as they do not have a knock sensor. On straight 93 Ethanol my engine pings if I do not run octane booster. Ethanol here in CT is 10% alcohol and 90% crap gasoline.

Robbie

 

[ulllose]

I've always run 92 or higher in all my performance cars, and assumed the higher the better for performance, can i tell a difference between 92 and 94 octane in the seat of the pants --hell no--is there a performace difference?? not sure but if just in case i always get the highest available.
Now at the same time my Lincoln Aviator tells me 91 or higher but 95% of the time I run 89 octane. I took a trip to texas last year first tank 89 octane second tank 91 or higher, etc etc i realized i would get the same MPG and total miles per tank no matter what octane 89,91,92,93 i didn't try 94. Moral of the story truck runs just fine on 89

 

[Sellshomesdrivesviper]

Unless I'm missing something, the gas stations in SE Florida have three choices 87, 89 and 93, I use 93.

 

[GR8_ASP]

Here in Germany you can get 4 different octane fuels, 91octane, 95octane, 98octane and 100 octane.

The prices for 91 octane are round about 6,01$ per gallon
95 octane 6,15$ per gallon
98 octane 6,71$ per gallon
100 octane 7,05$ per gallon


Don´t worry, be happy with your fuel prices...

In the US octane is rated as R+M/2. In Germany I believe it is Research only. Can't compare the numbers directly. Depending on the composition of the fuel, the MON (motor octane number) of a modern gasoline will be about 8 to 10 points lower than the RON (research octane number).

 

[DR EVIL]

I've always run 92 or higher in all my performance cars, and assumed the higher the better for performance, can i tell a difference between 92 and 94 octane in the seat of the pants --hell no--is there a performace difference?? not sure but if just in case i always get the highest available.

using a higher octane gas than what is necessary causes a LOSS is performance. Use whatever the manufacturer recomends.

 

[Tranzow]

Max 91 octane hear in AZ. Noticed pinging for the 1st time about two months in my 05. Thought it might be bad gas, but refueled a few times and it didn't go away. I guess I have to use octane boost.

 

[Newport Viper]

Max is 91 in CA. Have not noticed any problems here.

I use Chevron. Top Tier!?

http://www.toptiergas.com/retailers.html

 

[ulllose]

using a higher octane gas than what is necessary causes a LOSS is performance. Use whatever the manufacturer recomends.

I understand that but manufacturer's will recommend PREMIUM fuel only 91+. So to me that means atleast 91 octane, and thats what my liincoln says. But like i said before running 89 octane in it didn't change anything. I'm assuming that the ECM would go into the low octane table and adjust from there.

 

[MikeR]

Typically price difference is about .20 between premium and regular. So I can spend about $3.50 for a gallon of premium or $3.30 for regular.

So I fill up with say 15 gallons..... 15X $3.50= $52.50 fill up
So I fill up with regular to save big money 15x $3.30= $49.50

Wow, your right, we can save alot of moola......................
Stick with premium, its what manufacturer recommends. You would expect a high performance car to take premium. I was suprised though that our new Audi Q7 with 3.6l V6 still required premium. I thought it would take regular as its not meant to be performance oriented. Still, Id rather have the best octane to a degree, no need to fill with 100 but dont want crap gas either. Just use premium and dont worry about it.