Tuning Kit (Asphalt 8)

The Tuning Kit is a powerup introduced in Asphalt 8: Airborne.

Usage
The Tuning Kit can be used before the race using a powerup selection before starting a race (if you don't have one, it costs a number of Credits to activate one, depending on your level). Each unit lasts about 15 minutes. During this period, it upgrades every aspect of every car you own by adding an extra level to all current upgrade levels of the car. This powerup can be replenished by winning cups or finishing certain collections.

If the Tuning Kit boost is activated, a boost icon will appear in the main menu along with a timer indicating how long the boost will last. A timer will also appear on the Boosts-screen indicating the remaining time of the activated boost.

Trivia

 * The Renault DeZir earns the highest Tuning Kit bonus with 128 points, beating the Ford F-150's 95 points, with only a 33 point difference between the two. All the other cars receive a kit bonus smaller than these two. Thus, the sub-Class A cars receive the highest average kit bonus, while the Class A and Class S cars have the least bonus.
 * In spite of the fact that the SSC Tuatara has the smallest gap of minimum and maximum rank, it does not receive the least Tuning Kit bonus.
 * As of the Dubai update and Winter update, the tuning kits have been changed significantly. For example, Tuning Kits applied on a maxed out McLaren P1 (Rank 1611/1611) now award it with only 33 points, making it 1644, as opposed to the pre-Dubai update's bonus of 50 points.
 * Also, when maxed out, Tuning Kits only award ~80% of each aspect to the car, while acceleration awards 96.97%.
 * Three boosters (Double Credits, Nitro Starter and Tuning Kit) were added in Update 1 in November 2013, when the game was made freemium and a new car was added along with Time-Limited Events and customizable controls. (source 1, source 2)
 * In earlier stages of the game (around February 2014), the Tuning Kit powerups received as trophys in the Time-Limited Events lasted for 8 hours. At that time the Nitro Starter would last for 2 hours and Extra Tank for 4 hours. So, Tuning Kit powerups' duration has been reduced to 1/32 of the original values (a ~96.9 % reduction in duration), and Nitro Starter powerups' duration has been reduced to 1/12 of the original values (a ~91.7 % reduction in duration).
 * The cost of one booster minute before and after the latest booster update:

New Nitro Starter: 7,500 credits / 10 min = 750 credits/minute
 * Old Nitro Starter: 15,000 credits / 120 min = 125 credits/minute

Old Tuning Kit: 40,000 credits / 480 min = 83.33 credits/minute New Tuning Kit: 10,000 credits / 15 min = 666.67 credits/minute

Source: Touch Arcade: Universal Asphalt 8: Airborne - (by Gameloft), page 1317 (the duration of the Nitro Starter in the calculations on that page is (erroneously) stated as 15 min).
 * The cost of one Nitro Starter booster minute has increased by 600 % and the price of one Tuning Kit minute has increased by ~800 %.


 * After The Great Wall update was released in March 2014, the 2 hour Nitro Starter cost 9,000 Credits and the 8 hour Tuning Kit cost 24,000 Credits (source: YouTube (rrvirus): Asphalt 8: Airborne v1.3.0 (The Great Wall Update) [@ 1:09]). Compared to the the price level roughly a year later, the annual average inflation rate for Nitro Starter is 900 % and the annual average inflation rate for Tuning Kit is ~1233 %.
 * Nitro Starter: 75 credits / minute &rarr; 750 credits / minute = 900 % annual average inflation rate = the prices are doubled every 3⅔ months.
 * Tuning Kit: 50 credits / minute &rarr; 666.67 credits / minute = ~1233 % annual average inflation rate = the prices are doubled every 3.26 months.
 * This rate is well above the limits of hyperinflation, and in real life numbers like these would cause major difficulties in the economies in question. Such numbers (inflation rates over one thousand percent) are rarely seen, usually only during war-time or at the time of a collapse of a nation (the Weimar Republic of Germany economy in the early twenties, The Soviet Union hyperinflation in the early nineties and the Robert Mugabe -era in Zimbabwe early 21st-century are all text-book cases of hyperinflation). In a normal economic recession, the annual average inflation rates tend to keep well below 30 % in all commodities.
 * A car that has been upgraded to Level 4 on all aspects and has a Tuning Kit on will behave exactly the same as a car with maxed out stats and no Tuning Kit.
 * This is assuming that Pro Kits aren't applied.
 * In Infected mode, Tuning Kits increase the car's top speed when infected.