Fuel Octane

[knightjp]

I have just been reading about how you can increase or decrease the life of an engine just by using the wrong octane fuel.
The thing is that here in Dubai, we have four grades.
Super - 98 Octane
Special - 95 Octane
E-Plus - 91 Octane
Diesel

I'm not sure as to what standards the octane levels being calculated, but I have heard from many forums and online posts that the recommended octane is 87 or 89 octane (US pump gas spec).
I know that the octane grades are calculated differently and I'm not sure how I can find out what would be the correct Octane fuel to use in my truck.

At the moment, I am using Special - 95 Octane, as that is what most people use. But if switching to Super or E-Plus will be more beneficial in the long run, then that is what I will do.

Any comments or ideas?

 

[caulk04]

Most likely your fuel is rated on the RON scale where North American fuel is an average of RON and MON. That makes your labels a higher number but similarly graded in actuality.

Try the E-Plus and see how it runs. You may see some reduced performance resulting from the PCM pulling ignition timing to stop it from pinging. If you do, just bump back up to Special and enjoy.

Running an octane higher than your engine needs will do nothing but empty your wallet.

 

[Burla]

I don't think going higher in rating is as bad as going lower for engine longevity, but you are just wasting your money. You can get a tuner and tune for higher octane, but I just wonder why not just run 91? My truck drives sick on 87, but runs like a race horse on 91.

 

[knightjp]

I don't think going higher in rating is as bad as going lower for engine longevity, but you are just wasting your money. You can get a tuner and tune for higher octane, but I just wonder why not just run 91? My truck drives sick on 87, but runs like a race horse on 91.

I'm not too bothered about fuel and gas prices as my work contract states that my employer will take care of the 1/2 the fuel bills and vehicle maintenance. So price is not an issue at the moment and gas is still quite cheap over here as compared to other parts of the world.
So I have been running 95 Octane. I just wish I knew how Dubai gas companies publish their octane rating. Some say it is just direct RON and I know that in the US, it is the average of the RON & MON.
So far the truck has been running fine on Special - 95 Octane and most SUVs and Trucks here use that as well as 98 Super. I am just wondering whether by the rating whether I actually should be using 98 Octane instead and just plain ignorance would cause me issues in the long run.

 

[caulk04]

It won't cause an issue, the PCM has knock sensors and programming to pull timing if there's any pinging which will prevent damage.

 

[tidefan1967]

European RON 91/92 octane is equivalent to 87 MON and 95 RON is equivalent to 91/92 MON so If I were you I might consider blending the two(fill up with either/or every tank) or just continue running the 95 RON you said you were currently running because of the heat you have there.

 

[knightjp]

Well as it turns out, all my fears and worries were completely unfounded. What was really worrying me was the fact that I could not find a single bit of information from any of the gas company websites that told me how they calculated their octane rating. I had to rely on what I read in 3rd party forums and threads, which is mostly personal experience and guess work.

In truth, Dubai uses the standard RON rating..



So I was actually using the correct fuel all along. According to my manual, I'm perfectly fine with Special 95 Octane. It is the recommended one.



So sorry my stupid question and for wasting your time. Thank you all for the comments. I can only hope that someday this information will be useful.

 

[seabrook]

lol i’ve been telling people to not use 89 (us) for performance. i would only use us 91 or 93

 

[HEMIMANN]

Higher octane than the engine is capable of burning via spark ignition timing advance causes significant extra engine deposits. Do not buy higher than specified octane for a stock engine. Period.

I worked at a major engine maker for 22 years. Diesel, gasoline, methane, and propane fuels.