"Bleifrei Normal" means "unleaded normal" and this would be a roughly equivalent reminder as the "unleaded fuel only" sticker that the importer/converter would have placed in the cluster.  The "Bleifrei Normal" sticker inside the fuel door is indeed placed there by the factory in Graz. 

 You are correct that the 104.996 specified for the G320 was spec'd with 210 BHP, with the 104.992 specified for the US-market 1993-1995 300E/E320 models was spec'd with 217 BHP.  I believe the G320 likely would have been spec'd with lower compression because the factory felt it may well be used in markets with lower available (i.e "regular unleaded") fuel quality, whereas the US-market E320 is supposed to be used with "Premium Unleaded" fuel of octane rating 91 or higher.

Note that the HFM injection system, as used in the 104.99X engines, is an integrated (Motronic) system that combines the fuel and ignition control systems.  It will automatically adjust ignition timing and intake camshaft advance levels to match the available fuel, using two knock detectors that screw directly into the block of the engine and are inputs into the HFM computer. It is possible to use lower quality ("normal unleaded" fuel and have the engine in an E320, or G320, with a 217BHP computer from a sedan run just fine.  May not develop quite the power, but the computer will keep things from knocking or detonating automatically.

Best rule of thumb, which I have always done in all of the MBs I have ever owned, is just to always fill the tank with Premium Unleaded. I have never owned a Benz sedan that did not require premium gasoline.

Your data card is attached, as printed from the MB EPC.  These are the official records that the factory has in its part system about your truck.

Nazrat.pdf (60KB - 2 downloads)

 Since my truck is not a US model, it does not have a US VIN, and uses the MB chassis ID number as its official VIN.  US VIN numbers are different than MB chassis ID codes (for the US market, not for other markets).  There

 See attached data card for my truck, and you'll see the extra code number.  I've seen this extra digit placed after the chassis ID codes on all MB models.

Example from my 1989 560SEC:

US VIN:  WDBCA45E6KA466839

MB chassis ID:  WDB1260451A466839 5

GVZ-G320.pdf (59KB - 3 downloads)

The M104 G320 only need Regular Unleaded as stated in owners manual "91 RON"  which equates to 86.75 US.  That's all I run.  Not trying to cheap out, just that what it calls for and have yet to hear any knocking.  I do run premium on my other MB cars that require it. As Gerry stated, most MB run on premium except for those lower compression motors used on various G models through the years.  

I also think people confuse 91 RON as being the same as US octane rating 91 which it is not. 

http://www.pencilgeek.org/2009/05/octane-rating-conversions.html

Mike

(fuelg320.jpg)

(g320fuel2.jpg)

fuelg320.jpg (84KB - 0 downloads)

g320fuel2.jpg (59KB - 0 downloads)

 Good point.  I did not even think of that.

 Do you think the HFM resisitance trimming plug needs adjusting as well ?

 Thanks !

 I gotta ask...did you disconnect battery and turn ignition off before the swap ? If not, maybe the OVP relay (below the K24 convenience relay with the fuse inside) could have blown to protect any surge to the ECU ? Maybe check the fuse inside the OVP relay.

 I only say this as I had problems when I disconnected all relays to check contacts while battery still connected and ignition on.  I had an OVP relay issue right after with symptom like you describe.....maybe coincidence? A new relay solved my problem.

 Sorry to hear your master plan has a hiccup.

Looking at the date code on the "new to you" ECU, it appears to me as if it is a late 1995 unit (for a 1996 model year G320), and thus would include the more "advanced" DAS/immobilizer system that is coded to the vehicle. I bet that a 1993-1995 model year US-spec E320 ECU will work just fine, or a 1994 or early/mid year 1995 G320 ECU.

Cheers,

Gerry