The oil slick and its dark eco variant the flame slick are defensive racing weapons featured in Jak X: Combat Racing. The weapon will expel a streak of slippery oil behind its user's race car, causing no damage of its own yet all but eliminating the tire traction of those who drive over it (causing its victims to lose control, especially at high speeds). The flame slick is identical, except the oil is set aflame, delivering crippling damage to opponent racers.
Both weapons deploy oil for roughly two seconds, meaning the faster your vehicle is going the longer the streak of oil will be. Thirty seconds after the weapon is first activated, the oil will begin to evaporate in the order in which it was deployed, taking the same amount of time it took to deploy to evaporate.
The most effective use of the oil slick is to strategically deploy it around sharp turns or in areas where control is otherwise necessary to avoid crashing (such as in front of a split in the road). However, it can also be somewhat useful in deterring unsuspecting tailgaters. Other than this, the oil slick is notably inferior to other red eco pick-ups, as it is clearly visible ahead of time due to its oily glisten, and easily avoidable with jump jets or responsive driving.
The flame slick on the other hand is much more useful, as the damage it deals to opponent drivers is outstanding. However it is still visible and easily avoidable, even moreso due to the flames, therefore strategic placement is still necessary.