brettmf

I've put nothing but high octane in my E55 92/93 octane.

Never did this with other cars but need to protect the beast.

I'm just wondering if anyone goes below high octane in there 55s and if so, any issues? How many miles have you put on without the good stuff/

smiley47

In AZ our premium is 91 octane. My E63 came from Texas where premium is 93 octane. I've had no problems using 91 for the past year. The sensor recognizes the lower octane and makes the necessary adjustments (up to a point). However I wouldn't recommend using 87 octane if that's what you're considering.

shardul

iTrader: (1)

engine will be more prone to detonation with a lower octane gasoline

Nstar

93 is the recommended octane for our cars. 91 will do, and it's all people can get on the west coast unless they pay $8 for "race gas". Anything less than 91 is okay in a squeeze, but making a habit of it is a bad idea for engine health and performance reasons.

Forrest Gump 9

If your car is on "STOCK FACTORY TUNE" you can even run 87 octane and be ok. Just don't make a habbit of doing it.

06E55

Good to know that about the 87 octane! I was in a pretty remote area a few weeks back and the only option was 87 octane. I didn't want to risk it, so I drove to another gas station which had 93 available. My car took the full 21 gallons so I definitely couldn't have gone much further! Won't have to face that situation next time... I definitely would have only put just a couple of gallons in it to get me to the next station to fill with 93, but didn't want to risk even that...

220S

It's not 93 octane that's recommend but 93 RON. 91 AKI (octane rating in the US) is the same as 93 RON (RON is used in most of the ROW.)

Do a search. This has been all covered in depth here on MBWorld.

https://mbworld.org/forums/4432817-post27.html

https://mbworld.org/forums/w211-amg/...-question.html

brettmf

Interesting stuff. Here in GA, it's 87 89 and 92 or 93 on tap.

I've only used the high test.

Nstar

I'm pretty sure you're wrong on this and you'll find that 93 RON isn't even the minimum grade fuel for performance cars let alone the recommended.

91 AKI is actually equivalent to 95 RON which is the minimum available in europe and the minimum recommended. I haven't done a search or clicked the links but used to work in Europe so this is off the top of my head.

The "super" in Europe is 97-99RON which equates to the East coast's 93 AKI.

220S

Look on the fuel filler door: 93 RON minimum.

I now realize that you were saying that 93 octane is recommended. And I didn't mean to say 93 RON as 'recommended.' I meant to say 93 RON is the minimum. My fault there. So yes, I agree. And yes, 91 AKI is a close equivalent to 95 RON using (R+M)/2). Click on the first link. There I said "95 RON is the equivalent of 90-91 AKI (in the USA.)"

In the post I made above all I was really trying to say is that using 91 AKI will be within the 93 RON minimum. So if you use 91 AKI (which is the highest available in CA) you'll be okay with the 93 RON minimum. I didn't want people thinking that the 93 minimum required was AKI. Some people see the 93 figure and immediately assume it's AKI, when it's actually RON.

tbal

If you cant afford the gas perhaps e55 isnt the solution for you. 91 is the bare min. on STOCK TUNE,87 octane is garbage, your motor will eventually start knocking, performance will suffer, and like some members said... detonation.

brettmf

Like I said, haven't used anything but the good stuff. It was a general question to see if folks have used it, tried it in emergencies, etc.

tbal

Im just speaking in general, not to nab at you or anything

Low octane possible yes, advisable no, its simple as that.

SuperchargerV8

98 on tap here in australia and alot to pick from

220S

I thought Australia uses the RON rating

We're primarily talking about octane (AKI rating) here.

Last time I was Down Under, it was 91 RON, 95 RON, 98 RON. Shell was selling 100 RON several years ago.