[dberns]

I noticed that a Sunoco gas station near me has a pump labeled something like "racing fuel", 100 octane, "street legal".

(I take it the last phrase is there to emphasize that it's lead free).

I've been tempted to try some just for the hell of it... but figured
I'd better scratch my head first and check if there's the
slightest chance it would damage my beloved Insight.

(I could head down the road another half dozen miles to
Teterboro Airport and get some good ole lead enriched
fuel [a], but That would be Very Wrong)

Has anyone played with this stuff? Thanks

[a] aviation fuel still has some lead in it. Not as much
as a decade ago, when Superman could have used
it as a Kryptonite shield, but still an annoying amount.

url for some info on Sunoco:

http://www.sunocoinc.com/Site/Consumer/ ... o260GT.htm

 

[Resist]

If an engine isn't designed for higher octane fuel, it won't improve anything.

 

[Guillermo]

I've used both 87 and 94 octane Sunoco fuel many time for summer street driving and race track time trials. I never noticed a difference. Now that I have a race prepped civic for the track, i just use 87 octane in my Insight.

 

[jbrasure]

I'm not sure about the Insight, but many cars actually get better gas mileage with lower octane gas. I believe the only advantage of high octane gas is that it reduces engine knocking. If your car doesn't knock with 87 octane, then just use that.

 

[kapps]

jbrasure is right. The higher the octane, the more it resists ignition. This allows you to run a lot of boost but has a lower total power potential than lower octane fuel. The Insight was designed for 87 octane and 87 octane will give it the most power. If you had a turbo and 100 octane allowed you to increase the boost by a few psi, then thats a differnet story.

 

[Insightful Trekker]

For the last thread on octane vs. damage see:

http://www.insightcentral.net/forum/vie ... php?t=4232

However, the lead issue is very plain, clear and leaves tell tale evidence. Expect O2 sensor and CAT damage with as little as one tank. Its likely you'll be "caught" holding the bag for $1700 +. :shock:

In a more reasonable range of octane (93 max) the Insight can take partial advantage of higher values since it has a knock sensor and will adjust the ignition timing accordingly.

But kapps scenario fits the bill most completely.

100 octane in an Insight :?: IMO no benefit and possible "damage" from repeated usage.

HTH!

 

[ed kayen]

According to the car manual, the Insight was designed for 86 octane, which is probably more available to the European market. So 87 octane, being the norm for regular here in the states, is a higher octane to begin with than what is the recommended as the minimum octane for our beloved Insight.

 

[radiojim]

My 2006 Owners Manual states, "87 octane or higher" or some wording to that effect. It does perform better with 93. I agree with John, the Insight can take advantage, to a certain limit, with something higher than 87. I believe that to be the intent of the statement in the manual. I don't believe they meant 100 octane, which my '71 Lincoln just loves.

 

[Guillermo]

According to the car manual, the Insight was designed for 86 octane, which is probably more available to the European market. So 87 octane, being the norm for regular here in the states, is a higher octane to begin with than what is the recommended as the minimum octane for our beloved Insight.

I saw 86 octane fuel during a road trip in the high elevations of Colorado, USA.

 

[Insightful Trekker]

Higher altitude = thinner air = lower dynamic compression = lower octane requirement.

 

[JeffKinTN]

Regular is 85 octane here in Denver.... BTW, JeffKinTN is now in CO.....

 

[Dougie]

Also be careful comparing US octane numbers to European numbers, as the measuring methods are different. Sunoco 94 octane gasoline doesn't have lead in it...maybe the racing fuels do, though. But they aren't at your neighborhood gas pump.

 

[dberns]

Ok, just for the hell of it I figured I'd give it a try as it was time for my monthly fill up... The fuel gauge hit empty (no lights...) and, about ten miles later, I added in five gallons of the Sunoco 100 octane stuff.

(again, this is 'street legal" and they make a big point of that.. there's no lead or other common nasties in it).

Oh, it's absurdely expensive.

I didn't notice any change in some local trips. There _might_ have been a slight mileage improvement but there's so much noise in short runs that I couldn't say for sure one way or another. (And it sure wouldn't compensate for the big cost difference).

Anyway, I had my Insight fun for the week...

 

[originalbadbob]

Here in South Carolina, Sunoco has really high sulfur (478ppm) .
That's why I don't run any of it.
robert

 

[Guillermo]

Sunoco USA and Sunoco Canada is very different.
In Sunoco Canada has the lowest sulfur content compared to other brands, and I have heard several times that in the USA it's the other way around.

 

[akwehl]

octane

I saw 86 octane fuel during a road trip in the high elevations of Colorado, USA.[/quote]

I have driven all over the us since retiring in 1990 and never seen 86 octane. Moved from LA, Ca in '02 and here in SLC, Ut as well as Denver or anywhere above about 4000 feet our regular is 85 octane. When I go back to LA or lower levels it is 87 as always.

And because of the warnings in owner manual I wish I knew 85 would not hurt me. Today for first time I went to 88 octane and paid $2.15 when I could have paid only $ 1.98

 

[Insightful Trekker]

Re: octane

And because of the warnings in owner manual I wish I knew 85 would not hurt me. Today for first time I went to 88 octane and paid $2.15 when I could have paid only $ 1.98

Well if you had read the thread you could have saved $1.50 or so of the difference. <shrug>

85 octane at high altitude is functionally equivalent to a higher octane fuel at a lower elevation.

 

[rtm242]

Salt Lake City, Utah also has 85 octane fuel all over the place.

It is indeed an altitude thing, I'll probably put 85 in my Insight once I move there later this year, though you might consider how long the fuel will be in the tank...

Last time I went through there with our Honda Pilot, we used 85, but we topped off with 87 before the altitude dropped.

-Shawn

 

[mattcand]

higher octane rating doesn't mean more power

I don't know if people realize this but the octane rating is a measurement that tells us when a fuel is going to detonate. The reason a race car needs higher octane fuel is so it will not detonate as well as with a Nissan 300z or even one of the high end Toyota Matrix's that requires 92 octane. These cars have either higher compression ratios or have super/turbo charging that in effect increases the compression ratio. If you have a higher compression ration, you will make more power with the same amount of gas but you will need a higher octane to keep from detonating.

Probably the most important thing to realize about this is that 85 octane fuel has some additives to bring the fuel to 85 octane, 92 octane has more attitives and 100 octane has even more. In my airplane I need 100 octane and the do this by adding lead. If you can't add lead you have to add other stuff. The key to this is additives. When you add these additives to the fuel you are taking away fuel. The fuel is what creates the power the additives are what allow it to function in your engine. If your car can run on 85 octane fuel and you put 100 octane gas in it, each gallon of gas will contain less energy because of the additives. You will be reducing your power/gas mileage, not increasing it.

Matt

 

[radiojim]

Gasoline weighs in at 6.25 pounds per gallon. Maximum additives allowed (no matter if it's 85 octane or 100 octane) is 2.4 grams. The "Name Brand" refineries can crack gasoline up to 90 octane. Their 85 to 90 octane fuels contain only additives (up to 2.4 grams) to enhance their ability to burn cleaner and vaporize better, which results in cleaner injectors and less deposits. To obtain 91 octane and up gasolines they have two choices. Crack the 90 octane again, which means a much high cost per gallon, or rearrange the various additives to achieve the same goal. Still only a maximum of 2.4 grams per gallon. The second choice being the least costly, but still higher than the enhancing additives which they will still have. No way can we tell the difference in up to 2.4 grams of less gasoline per gallon.

"Name Brand" fuels intended for av-gas are double or even triple cracked to obtain 100+ octane levels, thus it's much higher cost. The lead is added for small adjustments in octane levels and for valve stem lubrication, cylinder head temperature control, and last, to keep the cost down as low as it is. You might remember the first AMOCO 101+ "white gas", it's cost at the pump was twice it's leaded counterpart. It was the first no-lead gasoline and was triple cracked.

The improved performance, which converts to increased fuel mileage, of using a higher octane fuel only works if the automobile engine has the ability to increase ignition timing and/or is a high compression animal. Our Insights are just that. Soo, use what you want, as long as it's at least 87 octane or 85 if you live in the high mountains. But, if you want to have it run just alittle smoother and perform just alittle better and your pocketbook can handle it, try 91 or 93, It will show.