how many members in taxi ?

[snakeshadow]

I am using my level 120 nuker to level 2 more characters , any idea if i should make it 8/8 party or less to get max xp?

[ltsune]

You should put low-level characters into the party until the average level of the party is lower than the mobs you're killing.
This will grant an exp/sp boost!

Basically:
Main char = 120
LevelChar 1 = 40 (just an example)
LevelChar 2 = 40
RandomChar 1 = 1
RandomChar 2 = 1
RandomChar 3 = 1

With the example above, simply make this calculation:
120 + 40 + 40 + 1 + 1 + 1 = 203
203 / 6 chars = 33.83.

In the above example, you may kill mobs higher than level 33 to still get your boost.
Therefore, if you're leveling at, say, level 80 mobs, you'll do fine with only 1 or 2 low level chars apart from your two "main" leveling chars.
I hope this makes sense?