single engine FMGS fuel predictions

[che ci dò che ci dò!]

Guys,
in single engine, if one doesn't push the "EO clear" prompt on the MCDU, FMGS fuel predictions are still reliable, right?
If one does push the "EO clear", then it reverts to two engines condition and the relevant predictions are not reliable any more, thus forcing the pilot to go to the relevant QRH table.
Is this right?

[che ci dò che ci dò!]

..sorry, I forgot to mention that my question was relevant to the A320..

[Miguel Martins]

On the A320 family, it depends on the FMGS installed.
The FMS2 equipped aircraft will give you single-engine fuel predictions on all phases, down to the primary destination.
On the older ones (Legacy?) you'll lose all fuel prediction, except on the descent phase where it'll revert back to two engine predictions.

On either case, if you push the EO clear prompt two engine predictions will be displayed, and if still single engine, you'l have to check the QRH for predictions.

Safe flights!