octane boosting additives

[ian_79a]

Whats your thoughts on these and are they safe to use, best one to buy??

[Shuriken]

I've heard they are alright if you use them every now. I wouldn't bother personally (from an engine safety point of view).

Shuriken.

[Chaos]

I think my question would be 'why bother?'. Lots of people think that the higher the octane, the better the performance. It doesn't work like that. If you run on octane which isn't high enough, then sure booster fuel helps. If your car is compensating for knocking or pre-detonation by retarding the timing, then again it'll help by allowing the engine to operate at full capacity. You won't really know this though I suspect, as you won't know the ECU is compensating and adjusting the timing as in doing so it's taking away the symptoms.

The thing is, it's unlikely that a well-maintained modern BMW is likely to fit into either of those categories. If your car is designed to run on 95 or 98 RON, then run it at that and everything should be golden. An extra 1 or 2 RON may get you a small gain but nothing to write home about I'd have thought. OB additives are really designed for older sports cars with higher compression ratios and/or cars with a heavy carbon build-up (which therefore also increases the compression ratio). By adding the OB you end up with fuel that doesn't cause pinking or pre-detonation, thereby allowing for more power, better fuel economy, and prolonging the life of the pistons and rings (how often do you hear about cars needing new piston rings these days, as opposed to say 20 years ago? :)).

It's usually only a tenner or so for a bottle, so I guess it's worth a try to see if you notice a difference, but I wouldn't expect to see too much tbh.

[benny boy]

would you say its good to clean out the sh*t from fuel system chaos i use couple times a year to clean the fuel system

[Chaos]

That's a different thing altogether mate, but def worth a mention. It's absolutely a good thing in my opinion, the last thing you want is a bit of crap or some build-up in an injector. Never hurts to throw in some STP or something once or twice a year.

Also a good idea if you ever run out of fuel, cos the scabby bits laying in the bottom of your fuel tank will have been dragged all the way through the fuel system. It's not as bad as it was on older cars cos the feed is usually a little way up the side of the tank these days to avoid it being too bad, but on older cars with the feed on the bottom you'd get all manner of cruddy fuel and bits dragged into the fuel filter.

[benny boy]

carplan do one called hot shot which it high octane fuel treatment what they run drag cars on but only a small % begins with m cant remember name of it

[Chaos]

Methanol. The formulas for using it as an octane booster are a bit complicated, but basically you mix it with petrol and for every 10% of additive you get roughly around a 2-2.5 RON increase. 'Notrox Hot Shot' is the stuff you've seen I think, which claims to increase power but by cleaning the fuel system as opposed to be used as an OB. It's probably no better than STP but if it does the job then fair enough.

[adood84]

the dealer uses one of these on service , but they don't use it for preformnce they use it to clean .

[CA Automotive UK]

The main problem is the inconsistency of RON ratings from oil company to oil company . Quite often you may be paying for , say , 95 RON , but it's actually only 90 RON , this can and does happen , especially as enforcement regs for petrol quality are not particularly rigidly enforced.

Running with a GOOD QUALITY octane booster seems , in my experience , to help more often than not ....and if the petrol you have just bought IS as good as it is meant to be then there is no harm in having added the booster anyway .

On track days and hacking days I use a Methanol mix in my petrol , or C22 Avgas , mixed around 1 : 4 ratio ...believe me this works a TREAT, you can really feel it . Even though a car may be set to run on 95 RON and in theory a higher RON rated petrol should make no difference , a car always seems to run that little bit smoother and cleaner with a couple points more octane

My e36 M3 showed a 5.7 bhp increase running Methanol mix over 98RON

[Chaos]

Roy makes a very good point, borne out of experience. Whilst I've been talking about the theory of it, the practice is that 95RON fuel may not actually be 95. This is where I was talking about the ECU retarding the timing to prevent pre-detonation and piston damage, and you not even being aware of it. Running OB will pull the fuel quality up and allow the engine to run at full capacity. This is why you see power gains on some cars - it isn't boosting their power, it's just letting the engine use it all by removing the need for it to compensate down to the fuel's level.

My comments above are based on the theory of octane boosting and fuel detonation. Roy's are based on experience. They make a good comparison for you to judge whether it's worth doing for yourself imo. Like I said, it's not that expensive to buy these days, worth buying a bottle and trying it if you're tempted.

[CA Automotive UK]

also agreed ......

[Chaos]

Of course, the most important thing is... how nice does Avgas smell..!! Mmmmm better than even the smell from a new marker pen.. :D

[CA Automotive UK]

thank god you said that ..I thought I was just a weirdo for loving that smell :p

ooops ..there go a few more thousand brain cells

[ian_79a]

thanks for all the feedback where do i get this Avgas from?

what do you think of this stuff: NOS Racing Octane Booster (ebay item 7977642681)

[CA Automotive UK]

G MAX CHEMS.

01832 731555

They deliver methanol and avgas etc all over UK