It should be fine, the 5w-50 will need changing more often then say the 10w-50, the viscosity gap is so large its at the limit of stability, in order to achieve this they prop the oil up with viscosity index improver to keep the oil in grade throught the temp range, is this large amount of VI improver that keeps the engine quiet.
Its not in the same league as the Silkolene but change often it will be ok.
Cheers
Guy.