Drewloera

Here in California gas stations usally only go up to 91 octane and thats just crap. I usally fill up at shell gas, cause I think its somehow superior gasoline. Last night my car was running low on fuel and I rememberd that theres a 76 in Covina that carrys 100 octane. so I fueled up to about half a tank.....@ a little over $9 a gallon. Car felt different as soon as I turned the ignition to leave the station, got on the freeway and felt like a powerhouse it was kinda scary Last thing I need speeding ticket...Anyone else running high octane..

JamE55

I'm always running high oct.

MB_Fahrer

I've got two drums of Sunoco 104 unleaded

Drewloera

The car really responds well to the higher octane rating gasoline. Only wish it was more reasonably priced. Thanks for the input guys....

Fabio D

Someone try the STP octane boost with 95octane gas? we try here the octane boost "stp" in to a RS4 bi-turbo with a 550hp powerkit with really impressive results, but i refused to try it in to my e55 yet. Someone?

Fabio Daniel

desired_speeds

I heard those octane boosters turn your sparkplugs orange.

RustbucketRacer

I'll be running 91 octane on a couple runs then 100, then 104 on the upcoming Mojave Mile. I'm curious to see any difference if any. Also, how the car's self timing will work with any possible detonation issues. I know a guy that ran half a tank of 112 in a W210 E55 at the drags. For some reason he consistently slowed down half a second, over 91 pump gas. HMMM? Too much?

Strigoi

You want to run the lowest octane you can without detonating. Higher octane fuel just burns slower so I'm not surprised that someone running 112 would lose power.

JohnnyRock

This doesn't make sense to me (not that I'm an expert by any stretch!).

First of all, where did he get 112 octane fuel? Most racetracks and race fuel that's commercially available is 104-105 octane. Was this guy in Europe? Is that a RON rating?

Anyhow, higher octane means the fuel burns slower ( as mentioned above), which translates into a more complete, fuller burn. This, in turn, makes the combustion chamber more potent and hence, provides more power.

On the topic of octane boosters, for the most part, anything you can get off-the-shelf at your local parts store is snake oil. One thing which does work is toluene, but it's pretty gnarly working around chemicals and stuff like that. Suffice it to say that I would recommend sticking to using race fuel or even adding half a tank to your normal 91 (or whatever octane your premium is rated at).

RustbucketRacer

First of all, where did he get 112 octane fuel? Most racetracks and race fuel that's commercially available is 104-105 octane. Was this guy in Europe? Is that a RON rating?

He drag races a few cars and has a hook up with VP. www.vpracingfuels.com
Maybe he had a special blend made? I'll ask. Possible also, that he was using leaded fuels. Not sure. And he's here in California, as am I. But I'll try and find out.
I never use fuel additives, never felt the need.
EDIT: my mistake, buddy says C12 is actually 108 octane, not 112. In his 900hp nitrous fed big block he runs C23 which is advertised at 120+ octane. This car runs low nines, Crazy.

LAMB09

This might be a dumb question but do you need a tune to pump 100 octane? Or can you just pump and go as is?

Mike G.

Lambo9,

Pump and go !

Mike K.

Strigoi

Have you guys done any actual research on running 100+ octane fuel? It's a waste of money on a stock (or close to it) engine. If you aren't detonating on 91/93 you will not see any improvement from it. Like I said before, you will make the most power running the lowest octane fuel you can without detonating.

If you do feel something, it's because you're convinced that higher octane equals more power. It's like doing a small mod that gains a few HP and you claim to get a huge SOTP difference. The car isn't really any faster, you just think it is.

Quadcammer

well I'm glad at least one person (strigoi) knows what they're talking about.

Strigoi

I missed this comment last night and you are 100% contradicting yourself with it.



Thank you. I was hoping that there'd be someone besides me on here that actually understands this stuff.

JohnnyRock

It appears you edited your original reply, otherwise I would have found it rather offensive since we've never been properly introduced.

First, I never claimed to have "expert" knowledge, I actually make this comment in my post.

Second, not sure how this statement contradicts myself, please elaborate.

Third, the comment you quoted me on was gleaned from several conversations I've had over the years with various automotive enthusiasts and 2 chemical engineers. It makes perfect (although, seemingly ironical) sense to me. Especially when explained from the standpoint of an "enthusiastic" engineer.

This poorly written rebuttal aside, I commend you on your comments that higher octane gasoline is a waste and that you only need enough to keep from detonating. This is great, real-world advice.

MB_Fahrer

I've been running Sunoco 100 unleaded and 104 unleaded. Car seems just fine. Don't know if the ECU's have just finally adapted to the altitude, but it runs much better. Especially when cold. Lots more wheel spin than with pump crap as well.

JamE55

Is your ECU tuned or is it stock?

MB_Fahrer

Stock

Strigoi

First off, I was a dick with my original comment which is why I edited it the next morning. I had too many drinks and was being a bit surly. I do apologize for that.

My contradicting statement was regarding that you get a more complete burn with a higher octane fuel on an engine that doesn't need it. Since the fuel burns slower you will not get as complete of a burn out of it. This is from over a decade of being on forums reading about this stuff and talking to people about this type of stuff. I also used to be big into mini bikes and octane was a big issue since we were all running upped compression with those engines. There's more of an explanation for my previous comment.