What octane you use?

[Broadsword]

I'm currently debating which octane to use 92 or 98. Right now I'm stationed overseas and those are my two options. My base has 92 readily available and 98 on the larger bases. Price for $3.93 for 92 and $4.19 for 98. My only concern is the stock N55 engine cannot cleanly burn the 98 octane causing gunk in the engine and BMW service on the economy is not cheap. Nor do they honor the service warranty or US factory warranty. Local warranty is only one year.

[dkreidel]

RON or MON?

[blue dragon]

Its all about the cetane, don't care about RON or MON

[JNoSol]

I use 92 and 93, min required is 89. 98 would be overkill, factory tune might not take advantage of it.

[Broadsword]

Originally Posted by dkreidel

RON or MON?

RON+MON/2 method

[wsybert]

92 will be fine. If you were running a tune, you might be able to take advantage of the 98.

[Phipsibear42]

Super always, never anything less... even in my beaters lol

[dkreidel]

Originally Posted by wsybert

92 will be fine. If you were running a tune, you might be able to take advantage of the 98.

^^^^ This if (RON+MON)/2

[krazpony1]

What is the highest octane I could run safely?

[Broadsword]

Originally Posted by Phipsibear42

Super always, never anything less... even in my beaters lol

Premium gas here is 98 octane; regular is 92 utilizing (RON+MON)/2 method. My base only has " regular" gas. I have to go to a larger base to get "premium". Gas on the economy has no octane rating and expensive.

[JNoSol]

Originally Posted by Broadsword

Premium gas here is 98 octane; regular is 92 utilizing (RON+MON)/2 method. My base only has " regular" gas. I have to go to a larger base to get "premium". Gas on the economy has no octane rating and expensive.

What defines regular and premium gas octane is determine by the elevation of where you live. In Denver, regular is 85. Where I live, regular is 87. Where you live, regular is 92 (first time I've heard of it to be honest). The higher the elevation, the less oxygen you have to burn = lower octane needed. The lower, the more oxygen = higher octane needed.

Newer cars have MAF, MAP, and knock sensors to address altitude. You can't go wrong using basic 92 Octane in your area. But if 98 is available and the standard for premium where you live, then use that. If you car reacts negatively to it, then switch back to regular.

[Broadsword]

Originally Posted by JNoSol

What defines regular and premium gas octane is determine by the elevation of where you live. In Denver, regular is 85. Where I live, regular is 87. Where you live, regular is 92 (first time I've heard of it to be honest). The higher the elevation, the less oxygen you have to burn = lower octane needed. The lower, the more oxygen = higher octane needed.

Newer cars have MAF, MAP, and knock sensors to address altitude. You can't go wrong using basic 92 Octane in your area. But if 98 is available and the standard for premium where you live, then use that. If you car reacts negatively to it, then switch back to regular.

That makes sense since the elevation of Seoul is 282 feet. Honestly I have no idea who supplies fuel to AAFES (Army Air Force Exchange Services) overseas.

[Harpinc]

There is no MAX octane that is safe to run. You are just wasting money on anything over the base octane that the engine needs to run efficiently. That number is resistance to detonation.