Compare to... 811 Adder Autarch Banshee 900R Bullet Champion Cheetah Cyclone Cyclone II Deveste Eight Emerus Entity MT Entity XF Entity XXR ETR1 FMJ FMJ MK V Furia GP1 Ignus Infernus Itali GTB Itali GTB Custom Krieger LM87 Luiva Nero Nero Custom Osiris Penetrator Pipistrello RE-7B Reaper Rocket Voltic S80RR SC1 Sultan RS Suzume T20 Taipan Tempesta Tezeract Thrax Tigon Torero XO Turismo Omaggio Turismo R Tyrant Tyrus Vacca Vagner Vigilante Virtue Visione Voltic Weaponized Ignus X-Treme X80 Proto XA-21 Zeno Zentorno Zorrusso The Declasse Scramjet is a weaponized Super Car featured in GTA Online on PS5, Xbox Series X|S, PC, PS4 and Xbox One, added to the game as part of the 1.44 After Hours update on August 21, 2018. It's equipped with a Rocket Boost, that can be used for very quick acceleration and as a rechargeable speed boost.
The Scramjet can be purchased in GTA Online from Warstock Cache & Carry for a price of $4,000,000. The Scramjet can be stored in any of your Properties/Garages as a Personal Vehicle. It can be customized at MOC / Avenger Workshop. Once acquired, you can request the delivery of the Scramjet from the Mechanic. However, the Scramjet cannot be used in standard races.
The design of the Declasse Scramjet is based on a real life 1960s Anime series Speed Racer, Mach 5, Alfa Romeo 33/2 Coupé Speciale.
The actual top speed of the Scramjet in GTA V is 130.75 mph (210.42 km/h) when it's fully upgraded, as it's been accurately tested in-game by Broughy1322.
Yes, you can sell the Scramjet at MOC / Avenger Workshop for a resale price of $2,400,000 (60% of the original purchase), plus 50% of the value of your upgrades.