A couple weekends back I ran the FD from Montgomery, AL to Peoria, IL. On the way back was needing gas and pulled off in Clarksville, TN to get something to eat and gas up.

It was about 8:45 pm after I ate and started to get gas. There was NO 93 or 91 octane to be found ... anywhere at any gas station. I cruised a large portion of that town and all gas stations werre marked 'OUT' or '87 octane only.'

I was getting a bit worried because I was so low and it was a Monday night and Clarksville was rolling up the sidewalks. Then it occurred to me that I could stop by an autoparts store and get some octane booster.

I knew nothing about off the shelf octane boosters because I had never considered buying it before. Never needed to.

I bought STP booster and filled up with 87 octane. Now in retrospect (after searching the forums here) it appears I probably got about 0.1 octane boost.

That tank of fuel was used to get me down to Montgomery, and I probably never saw over 4 psi boosting up hills on the interstate. The car seemed to run just fine, smooth as ever.

Sorry for the long post, but what's a bitch to do if stuck in that scenario again? Only 87 octane available and (now) knowing off the shelf octane boosters are crap?

 

If you encounter the same scenario again, just do what you did. The N/A 2nd gens will run fine on 87. Higher octane fuels create a smoother burn and are less likely to detonate. As long as you stay off the boost and take it easy you should be fine temporarily. I wouldn't do it every day, but once in awhile is OK.

 

The car is certainly drivable on lower octane gas. Just DO NOT boost or you risk blowing an apex seal.

 

Yep, the trouble with detonation is when the car is under boost. I would have splashed in 5 gallons and looked at a later exit, but it works the same regardless.

The only thing you have to watch for is 5th gear under load. In 5th you may not feel like you're pushing the engine hard when in many cases you are at full boost. The boost gauge tells all. Just use 4th when going uphill to avoid this.

Dave

 

Thinking back, I could have probably added about 5 gallons and ran down to Nashville and looked again. But at the time, I was ready to get home (got home 1:30 am or so) and as I understood it at the time the octane booster was actually doing something, so I didn't realize what could have been. Luckily I didn't boost much on the way home and never got above about 4 psi.

 

since it was at night with lower air temps and only 4 pounds of boost I am sure you did not risk anything. in the future do the same thing.

Jeff

 

There are other additives that you can mix with lower grade gas to make it acceptable. Toulene can help and there is some other stuff, three letters, its name is escaping me right now. You might want to consider doing some research to be better informed on your options.

+1 for the "you probably didn't break anything if you really didn't boost" camp

 

Running lower octane doesn't automatically mean that you'll blow the engine. Lower octane ignites easier. That sounds good, but it can make it hard to control the ignition which is basically where the problem lies: pre-ignition (i.e. detonation).

So, just because you have lower octane, doesn't mean you "will" get pre-ignition; it just makes it more possible for it to happen.

 

Toulene and Xylene. Good luck finding either one at 1:30 in the morning...

http://www.gnttype.org/techarea/misc/octanebooster.html

You could pre-mix this stuff and carry it around with you but that's not very smart. Best to just keep off the boost until you can get decent pump gas in the tank.

 

yea i have run into this a few times driving through the country. Best option is to fill up a few gallons, not boost, and stop asap to fill up with higher octane.

i worked at autozone for years and all the octane boosters are pretty much junk. There are 1 or 2 that are better than all the rest but when it comes down to it they only raise the octane like 1 number.

 

you can drive your fd around all day on 87 octane aslong as your not boosting the engine, keel the rpms down whenever possible aswell

 

Yeah - I realize that 87 octane doesn't mean, "boom, dead engine." And I understand the purpose of octane. And obviously I didn't have a problem.

The concern for me was my ignorance about those off-the-shelf octane boosters, the fact that their lack of actual octane boosting could have led to big problems if I had run across a Cobra or something of the like on the interstate and gave them a pull, AND what to do if faced with that situation again (long sentence there). On the way home, I would have thought boosting to be perfectly safe due to my lack of understanding on octane boosters. Luckily I didn't boost much at all.

As it was, all I did was get out on the interstate, put it on 83 mph, hit the cruise, stayed alert for anything Mike Valentine had to say, and listened to some tunes. I never saw anything but a turbo PT Cruiser in Nashville. And I wasn't about to waste gas on him, even if he had wanted to give'er a go.

Parid - Research: Already done! That's what I did when I got home. And how I found out about the octane booster's ... uh, crappiness. Then I decided to add this post to find out what to do next time ... for myself and other new(er) FD owners. I added this post because most or all of the threads I found on here were people asking about how much power they'll get from octane booster ... and/or adding octane booster to 93 octane fuel. I didn't see a thread going about running into 87 octane only fuel.

Thanks for all the info guys. BTW - I run Phillip's 66 here at home. It's 93 octane and the only brand I can find in the area with 0% ethanol (E0)! I am/was a BP/Amoco Ulitimate (93 octane) lover ... until they started lacing it with ethanol (E10). Don't want ethanol.

 

The NOS racing formula would be the best booster to put in your tank that is usually readily available.

Having said that what boost are you running? And fuel ratio's if you know.

thewird

 

My goal is 10-8-10 (stock ecu) until I get deeper into reliability mods. The only problem I'm having now is spike, and it's ~controlled. I've got a needle valve controlling my spike, but it's adjustability is difficult. I'm thinking about doing the poor man's non-sequential mod just to get around spike, and the sucky way I'm controlling it.

And keeping the non-sequential for a while until I get around to an aftermarket ecm ... as part of the reliability stuff. AFR's, dunno. Whatever the stock ecu produces. I'm fresh off a paint job, and am starting to wade into reliability. If I'm going to keep this FD, I want it all done right.

 

I can't imagine you having a problem with 87 octane with stock boost. If you go non-sequential thats another story since that opens the flow a tad. If I'm wrong about this, someone please correct me.

thewird

 

A ball-spring valve controller may take care of the spiking entirely. I would change that first.

Dave

 

Roger, will-co.

 

Testing seems to disprove that:

http://volvospeed.com/Reviews/octane_boosters.html