if theres not a key hole then its probably a small button in the car otherwise you just pull it open.
Fuel door is locked when car locked, push on the forward part of door, the aft side will pop out.
Well on my 1991 Mercedes Benz 190e the fuel release door is automatic. All you have to do is make sure all the doors are unlocked with the master key and then, go to the fuel door and lightly press in on the left side of the fuel door and pull from the right and it should pop open.
The fuel door is a hinged door over the fuel-tank filling pipe cavity, and swings outwards, on a vertical axis, to be in open position.
The 2002 Mercedes-Benz S-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz G-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz SL-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz C-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz CL-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz SLK-Class runs on premium unleaded (required).
The 2002 Mercedes-Benz E-Class runs on premium unleaded (required).
Just push on one side of the fuel door itself (it is not locking).
there is no release you just push on the door near the hinge and it opens