yes very much so, and for a variety of reasons.
1.) While Ares is the god of war, he has been known to turn to Zeus when he loses battles. this suggests that Ares yields to and is aware of his father's power.
2.) Also, Zeus is the king of the gods. Number 1 of the geek gods. He basically personifies male desire to the Greeks, at least at the time he came about, which is often why he gets away with far more than the other gods do. Being one of the greats, he is even endowed with extra power.
3.) In the lore, he actually beat the old lead god, his own father, so there is proof of his power, and the ability for a god to best another god. In the process of doing so, he proved he was the strongest of all the other gods.
4.) His lightening bolt is considered the most powerful weapon the gods process. He was granted it after freeing others, and it helped him push the old gods out of the way and establish his rule. In theory, any Greek god of Olympus would be beaten by this weapon he processes.
5.) He has a natural charisma which helps him rally allies to his cause, so even without his bolt, Ares would likely also find himself going against a number of Zeus' supporters should he chose to fight his father.
In short, Ares would outmatched on a number of levels, and most likely would be easily beaten. He may even be aware of this, since he usually pipes down when Zeus is upset.