Will this actually have any advantage in the standard non-turbo I-5 engine, and if so, will it cause any damage to anything? I was just curious how far you can push this engine stock since it's got so much potential with a turbo and so forth.

 

It will not cause damage but will not help much though.

 

Octane boost is not really goign to do anything. If you add a bottle of say 104+ it doesn't give you 104+ octane gas. What it will do is, say you filled up with 93 octane, it will make that gas more like 93.5 octane.

 

Octane is a measure of resistance to detonation. High compression engines need higher octane since the more-compressed mixture is more likely to spontaneously ignite. That's called knocking or pinging and damages engines. Or can do so, depending on severity & duration.

If your engine doesn't need high octane gas, you gain nothing from higher octane.

Mill the heads, use a thinner head gasket, domed pistons, etc, to raise the compression, you need higher octane. Or if your combustion chambers are really carboned up (less volume = higher effective compression). But otherwise, a waste of money better spent elsewhere like new filters, cleaned injectors, etc. Or chromed wheels to make the car look faster.

That being said, if your car has a knock sensor that advances/retards timing based on knock, you MAY get a little more spark advance and power on higher octane. Turbos have this, and retard the timing if lower octane gas is used. I'm not sure about non-Turbos. Even if they do, the incremental increase isn't one that you'll feel in the seat of your pants as I've experimented in my wife's T5. Oh, and gas mileage may marginally improve with higher octane, too.

 

I can't think of a car out there made since 1993 that has a deaf motor. The gains, even with a turbo, are minimal at best with octane booster. I got some nice gains out a NA S60 I had a few years back for relatively cheap.

 

You want some engine knock discussion? Go to a Harley Davidson forum!
Those twin cam engines are notorious knock-producing machines being air cooled and lean burning and therefore hot. The original post here didn't list any year, and I'm not an expert on what year I-5 has what and what it doesn't. But I do know that without a knock sensor, the octane booster isn't going to help one bit.

I'm curious about your non-turbo S 60. Octane booster let the timing advance enough over premium gas to make a noticeable difference? I am surprised.

It isn't a cheap way to go, however, is it?

 

What? No i don't use octane booster I always run premium even on the non turbo I5. I was able to get gains by removing the resonator on the exhaust plumbing a cold intake pick up into a cut stock air box. Porting and polishing the head and combustion chamber, I made a spacer for the knock sensor. Pretty much all cost me less than $100 but only because I port and polish my own heads.

All I5's have knock sensors. At least on volvos they did.

 

Couldn't even tell you the first year I5's were put in production. But I do know the words to Little Deuce Coupe, and I think you make yourself the Volvo equivalent! Harley V twins have no knock sensor. Until a year or two ago, they didn't even have O2 sensors. Ping city, especially when it was hot out and the bike was moving slowly so little air flow was cooling it. Most cheat by tuning them rich with electrodevices to fool the mixture computer. Or longer duration cams, or both.

I was curious as my wife insists on using regular gas and I insist on using premium in her T-5 but I haven't noticed any "seat of the pants" difference, at least at the rpm's I use. Maybe I fill it enough that its usually running about 90 octane on average, I don't know. Fortunately, we can still buy real premium gas here of 93 or 94 octane.