Osama,
I can see this is your first post, but are you serious here?
You provide absolutely zero engineering data here and actually expect a sensible answer from anyone?
"Best" is a highly variable term in any case, and "not impact" is also very vague.
From that question my answer would be that the best required is no load change at all.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.