My comments are based on personal experiences. All I know is when I put 92 RON (our lowest grade in AUS) in the car or the bike, they feel "flat" compared to filling it up with 98 RON. I've also experienced "knock" in the car when running the lower grade fuel, although no problems with this on the bike. Down here we only really get 3 grades of fuel. 92 RON (unleaded), 95 RON (premium unleaded) and 98 RON. To be honest when you can feel a difference in performance from one grade to another and the cost on 7.5 litres of the "good stuff" is next to nothing compared to "egg juice, why not spend the extra 50 cents."
I don't really understand how Benzine or Sulphur help my bike or car run better?
Why do they put it in the fuel?
Yes I'm running an iridium plug in the KLX, based fully on the really positive experience I've had with them in my car.

 

I may be wrong, but I was always under the impression that the "grades" of fuel is just a marketing designation to get you to buy the "best" grade. When really all it means is just the octane level. A lower "grade" of fuel is just lower octane. It doesn't mean it has more sulfur or is less pure in some way. In only means that the higher grade has more octane. So it is a marketing word for when you fill up with "Premium" you think are getting better quality or a more refined fuel, but that is not the case.

Higher octane is required for higher compression engines to avoid pinging or pre-combustion. That is all. Octane is an additive that makes the fuel less volatile so that it doesn't pre-detonate under the higher compression. It doesn't make the fuel burn any cleaner. And lower octane fuels aren't "dirty". At least not any more so than "premium" grade.

My F-150 pickup is happy with 87 octane, or low grade. Thank goodness.

 

So should we just use 87 octane? I've always filled up with 92.

Mike

 

Generally you should run with whatever the manual says it needs, unless you find that it is pinging or something, there's no need to go to a higher octane.

The '06 manual said to use 87. I don't know about the '09s.

 

Yeah! I get all that stuff.
It doesn't alter the fact my car suffers some detonation under load with the [b]local[b] 92/95 RON fuels. The 98 Ron has cured this 100% and I feel the Iridium plugs have added better throttle response, which is just a small bonus.
The main reason for the plugs is the service schedule, it's 75000-100,0000KM. That's verses the 25000KM for the regular plugs. I have a Subaru, flat 4, RPITA to change the plugs.
It just makes life easier, all for a couple of extra bucks.
As for the bike, I would be hard pushed to say the plug has made any difference at all as I did so many mods all at the same time. As we know, new jetting and a pipe make [b]ALL[b] the difference.
It's well documented that over here in West Aus we get some of the poorest fuel available in Australia. Previously some Car manufacturers have withdrawn certain engines from the local market because of issues with the fuel. One case I recall was Mercedes with their high output common rail turbo diesels. It's a local problem not just isolated to petrol.
Lastly, one other factor is the hot dry weather we get at times in the year. The hydrocarbons in fuel evaporate at a greater rate during these times, essentially making the fuel "go off" quicker.
It's an interesting topic.

 

Yeah! I get all that stuff.
It doesn't alter the fact my car suffers some detonation under load with the [b]local[b] 92/95 RON fuels. The 98 Ron has cured this 100% and I feel the Iridium plugs have added better throttle response, which is just a small bonus.
The main reason for the plugs is the service schedule, it's 75000-100,0000KM. That's verses the 25000KM for the regular plugs. I have a Subaru, flat 4, RPITA to change the plugs.
It just makes life easier, all for a couple of extra bucks.
As for the bike, I would be hard pushed to say the plug has made any difference at all as I did so many mods all at the same time. As we know, new jetting and a pipe make ALL the difference.
It's well documented that over here in West Aus we get some of the poorest fuel available in Australia. Previously some Car manufacturers have withdrawn certain engines from the local market because of issues with the fuel. One case I recall was Mercedes with their high output common rail turbo diesels. It's a local problem not just isolated to petrol.
Lastly, one other factor is the hot dry weather we get at times in the year. The hydrocarbons in fuel evaporate at a greater rate during these times, essentially making the fuel "go off" quicker.
It's an interesting topic.
OOPS! Double post.