Superior Wizard Oil

Superior Wizard Oil is a potion that is applied to a weapon. When applied, the weapon will increase the user's Intellect by 40.

Blizzard did not release a new version of Wizard Oil for high level weapons in patch version 3.0.2 and this potion will not apply to most high level weapons obtained in Northrend. Wizard Oils have been discontinued along with Sharpening Stones for raiding beyond level 70.

Source
This item is made by Enchanters with a skill level of 340.

The Formula: Superior Wizard Oil is sold by:
 * Madame Ruby in Shattrath City
 * Lyna in Silvermoon City
 * Egomis in The Exodar