The 1999 C280 has electronic transmission controls. MY 1st step would be changing the fluid. Fluid doesn't last forever as MB used to state!

They now recommend every 40K services & the fluid is better than the type used in your trans.


Under normal low speed driving the use of low octane fuel will have little to no effect.
BUT any time you need to merge OR ask for power the knock sensors wil retard the timing & power output will be lowered, that can also affect trans operation.
Never use E85 ethanol & try to keep fuel at 90 octane in the tank.

Trans computer needs torque info from engine to operate properly.

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