Boost is one of the primary game mechanics in the Burnout series and is present in all Burnout games. As long as boost is active, the player's vehicle has improved acceleration and top speed.

The player's current boost level is indicated by a bar in the bottom left of the screen known as the boost bar. Performing actions such as drifts, near misses, and air time fills the boost bar, while crashing, being taken down, or boosting drains the boost bar.

Prior to Burnout Paradise, Boost is activated by pressing and holding the R1 button on PlayStation, the A button on Xbox, or the R button on GameCube. In Paradise, boost is switched to the cross button on PlayStation and the left shift key is used by default on PC.

Burnout, Burnout 2

Boost in the original Burnout and Burnout 2 is not usable until the boost bar is completely filled. When activated, the soundtrack fades out in the original game and the mix changes in the second game. Fully depleting the boost bar (an action known as a Burnout) results in it being refilled by a certain amount depending on the player's boost earning actions. If the boost bar is fully refilled by earnings from the preceding Burnout, boosting can continue in a Burnout Chain. If boost is deactivated at any time, it does not refill, and any ongoing chain is ended.

Burnout 3, Burnout Legends, Burnout Revenge

Boost in Burnout 3, Legends, and Revenge can be activated at any time provided there is boost available. In addition to the prior games' boost earning actions, takedowns fill the boost bar and, if not yet at the maximum, extend it up to x4 length. Similarly, crashing or being taken down shortens the boost bar. There are no Burnouts, so the boost bar is not refilled when empty; the player is expected to refill it via boost earning actions.

Burnout Dominator

Burnout Dominator uses a mix of the prior entries' boost types called Dominator boost. Like in Burnout 3, boost can be activated at any time as long as there is boost in the boost bar, but the boost bar always remains at a constant length. When the boost bar is filled, it turns blue and takes on characteristics of the boost used in Burnout 2, allowing for Burnouts and Burnout chains to be performed. This mode is referred to as supercharge and depletes faster than normal boost.

Burnout Paradise

There are multiple types of boost available in Burnout Paradise. Each boost type has different gameplay characteristics, and the color of the boost flames emit from the exhaust depends on the type used. Each vehicle uses a particular boost type which cannot be changed by the user except through mods.

Note that different boost types do not result in different vehicle attributes. This has been proven in gameplay by mods such as the Vanity Pack, which allow boost type to be switched on the fly.^{[citation needed]}

Speed

Speed boost, originally called Danger boost and internally called BoostBurnout2, is functionally identical to the boost type used in Burnout and Burnout 2. In addition to other earning methods, boost can be earned by smashing props around Paradise City.

Unlike in Burnout and Burnout 2, flame particles are emit from the exhaust pipes when activated. These flames are yellow and, prior to version 1.6, would begin forming smoke trails as the boost ran out.

Aggression

Aggression boost, internally known as BoostBurnout3, is functionally identical to the boost type used in Burnout 3, Legends, and Revenge, with the exception that it can only grow to x3 rather than x4.

Aggression boost is orange in color and, like Speed boost, would form smoke trails when about to run out prior to version 1.6.

Stunt

Stunt boost, internally called BoostBurnout5, is similar to Aggression but does not lengthen or shorten with takedowns and crashes, instead maintaining a constant length. It was altered in version 1.3 such that it could be stopped immediately after starting to boost, whereas the other types keep boosting for a short time before stopping.

Stunt boost is green in color and, unlike the other types, never had smoke trails even prior to version 1.6.

Development

During development, BoostBurnout5 was functionally the same as Dominator boost, where boost was usable at any stage and would turn blue when filled, becoming capable of performing Burnouts. This type is the only one present in Burnout 5 (2007-02-22 build).

Unverified rumors, citing an anonymous developer, claim this was originally developed for Paradise and was scrapped after EA UK co-opted it for use in Dominator. The type was not present in Paradise in in 2006 and it is not clear how this would have been achieved in such a short timeframe.

None

Boostless vehicles include the Hunter Olympus, Nakamura Rai-Jin Turbo, and all bikes. As the name suggests, boost is not present on these vehicles, though the two cars gain a grey boost bar when entering Showtime. Bikes use leaning forward as an effective replacement for boost, gaining both acceleration and top speed by doing so but limiting their turning capability.

Locked

Locked boost is used on the Carson Extreme Hot Rod. When activated, it locks on and never runs out. The only way to deactivate it after activation is to slow down with the brake or handbrake.

Switchable

Switchable boost is used on the Montgomery Hawker Mech. Pressing L3 on PlayStation, LS on Xbox, or the siren button on PC switches between speed, aggression, and stunt boost. The size of the boost bar may differ from the normal types.