You have a spell called Tiger's Fury, it's your friend. Moreover, it's most likely gear related too. Even as a well-geared feral, it still happens in fights that you're out of energy when you could really need it and you just have to autoattack for a few seconds.
There's a glyph that let's you use Savage Roar without combopoints. So before you attack, you can just use Savage roar, then first put a Rake up on the target so you have a dot rolling, then mangle, and when you're out of energy, use Tiger's Fury and some more Mangle , till you can use Rip or Fericous Bite at 5 combopoints, if your target is still alive then. Savage Roar lasts longer the more combo points you spend on it, but you can technically use it on none, with the glyph.
Last edited by SneakySams; 2013-08-07 at 09:13 AM.
Level 87 (or any level between two expansions) is a lousy benchmark for energy regen..
Regen is buffed by haste, and since levelling gear rarely have hast (lacking enchants/reforge/gems plays a BIG part here), you really can't use it for comparison.
When you are at max level (not just 90, but any max level for any expansion) and you gear up, you will see your regen begin to get better and better.. When you start a new expansion, you will start to mess up your gear, until you reach new expansion level cap, and you start to upgrade gear..