I have a '04 CLK55. I always use premium 93 octane gas but I keep hearing that it's a waste of money.
What octane are most people putting in their AMGs?

 

well i wish i can put 93 on mine! in California, ALL AMG owners put 91octane on theirs....BUT i know a couple that run 100octane race gas.

 

the 93 would be not so bad. the 100 is a bad idea because these cars are not running enough ignition advance to get a complete burn. drag race cars run high octane. but road race cars run lower octane but they are oxygenated and leaded. look at VP fuels spec sheets. some of their most sucessful fuels are in the 91-95 octane area. the 100 octane type stuff is for engines running turbo's with high boost type set ups. i roadrace motorcycles with close to 13.5 to 1 compression and the best fuels that VP supply for that application are in the 87-89 octane range with oxygen. higher the octane, the slower the burn. slower the burn, the more advance your ignition needs to create the proper flame pattern to completely ignite the fuel or your combustion chamber temps drop below a efficient level creating a unburned fuel condition that will lead to a roasted catalytic converter.

 

I run 91 here.

Andy

 

Thanks for the replies.

The lowest typically found here is 87 octane. What would be the harm in starting to use it? I'm just trying to figure out what benefit I'm getting by spending more money on premium 93 octane and would there be negative ramifications from starting to use 87 octane?

Thanks

 

I use 96 octane

 

With 11:1 cr I would not run less than 91 oct except for an emergency..... it's spelled out pretty clearly in the manual.

The car does have a knock sensor which should save you if you ping...... but I wouldn't chance it........

 

Please use from 91 and up for our CLK. I dont think u have to run 93 but definitely not 87. I mean NO.

Andy

 

I'll just stick with 93 and forget it.
Thanks again for the replies.

 

lol at 87....

 

87


Andy

 

mine pings with anything less than Sunoco 93.

 

In Aust, the options are 91, 95 and 98. I generally use 95. 91 will cause my engine to ping. 98 will get me about 5-10% more mileage and does run smoother but the additional cost cancels out any savings.

 

You guys have newer cars with better technology, so technically your rides should have knock detectors and adjust accordingly? So you can actually run 87 if you want... but not recommended.

 

no, i cant...it pings.

 

Our standard in the UK of A is 95 standard and Super is either 97 or 99 (Shell) 95 works ok but it runs smother on 97 - not too sure about mileage however as I'm often pedal to the metal

 

The reason European & Australian gasoline has a higher octane rating is the different rating formula. In the US the following formula is used:

(RON + MON) / 2

In most places around the world, the Research Octane Number (RON) is what’s posted on the pump. There is a second rating called the Motor Octane Number. Both numbers are determined using a variable compression engine, but the MON uses heated fuel, the engine is run at a higher RPM, and the ignition timing is adjusted during the test. The MON is always eight to ten points lower than the RON.


This means the exact same 98 octane gallon of UK fuel, is rated at 93 or 94 octane in the U.S.

 

Mine also, Nothing less than 93 here!