Powerleveling

New to multiboxing, so I have a couple of questions about grouping and levels.

1) I have successfully worked out how to Power-level a 80th lvl Hunter with an 85th lvl DK. But, I think I am docked XP, the XP earned seems to be less then if I was soloing. Unless I do not group the two, let the Hunter get the first hit, then kill with the DK. But the question is, am I penalized XP because I am in a group and the DK get's zero XP. DK can't even do the quests because she went through the zone already.

2) Can a 85th Lvl DK help level a 37th lvl character? If so, where is a good place and when kind of XP should I expect to get?

[Ualaa]

If your level 37 were to go to Scarlet Monastery, into the Cathedral.

The non-elite mobs, on the way in, might net you (I'm picking numbers here) 500 exp per kill.
But with the group sizes you might not make it in, solo.

With the DK (more than 9 levels above your toon)...
If you tag the mob, it is yours for looting.
But if it has 100 health (or percentage of its health is 100).
And you deal 3 points (or 3%) and the DK then one-shots it.
You get 3% of 500, or 15 experience and full loot rights.
If your DK was within 9 levels (say level 44), and you tagged it and they killed it, you'd have full experience.

With your 85 grouped with the 37.
Instead of 500 experience per kill, you might only get 200 experience.
But the 85 can in a single AoE attack (Blood Boil, an instant cast usable while moving) can kill dozens of SM mobs.

Once you get into the instance...
If you could solo pull the elites.
You might be able to take one at a time, assuming no adds.
And it would give you (again picking numbers arbitrarily) 2,000 experience per kill.
But be very deadly to you, and you'd die more often then kill the solo mob.
Any add, and you die automatically.
But with the DK going first, and your toon parked at zone in.
He can avoid mobs carefully... and head to the very last mob.
Attack it, which triggers every mob in the zone to attack him.
Run back to the entrance, via the water and jumping down, which messes up the mobs pathing giving him time.
Drop a Death & Decay, shortly before they get to him.
And as an 80th, need to play well to live (strafe while running, so you're full speed the same as moving forward but never with your back to the mobs)...
As an 85, you have so much health its unlikely any of the mobs can threaten you even if you were to AFK for a shower while they beat on you.

You can reset an instance only so many times an hour.
So if your DK took you into Cathedral and then Armory.
Then reset both instances.
And took you into Armory then Cathedral.
And reset both instances.
Each time, instead of getting 2,000 solo experience per kill...
Let's say you get 400 experience per kill.
But in 10 minutes, its not 3-4 mobs dead (4x 2,000 = 8,000exp) with significant risk of dying yourself.
Instead its 200 mobs (200 x 400 = 80,000exp)...

Yes, an 85 can help a 37.

In 3.3.5a I power leveled four toons (two RAF pairs) with an 80 pally, basically doing what Ualaa describes. When my RAF toons reached 20 (minimum required to enter SM), I started running SM. At that level, all the mobs are skulls to the lowbies. Pull the instances then kill the mobs. Loot, reset, repeat. After 5 resets (much less than 1 hour,) hearth back to town and empty the bags, train, drink a beer.

I powerlevelled the group through scarlet monastery, scholamance, Zul'Farrak, then Zul'Gurub. At 60 I went to outlands I did all the dungeons there, but then it was a team effort (tank, heals, dps) and at 70 I did Kara.

Then the 4.0 patch came out and with the changes to block (percent reduction instead of flat mitigation) I couldn't pull a full instance anymore.

It is a ton faster to level through instances instead of questing or solo mob kills, particularly if the mobs are red to the lowbie.