Performance upgrades for vehicles in Grand Theft Auto VI are projected to constitute one of the principal monetisation and progression sinks of the open-world economy, building on the tiered modification framework established at Los Santos Customs in Grand Theft Auto V and Grand Theft Auto Online (GTA Wiki, 2026). Within the GTA design lineage, performance tuning is abstracted from the granular real-world tuner culture documented by Wikipedia (2025) into a discrete, tier-based commodity system in which the player exchanges in-game currency for stat improvements affecting acceleration, top speed, braking, and handling. The series treats the modification garage as both a gameplay utility (wanted-level evasion, repair, vehicle storage routing) and an aspirational progression layer, where the visible aesthetic transformation of a stolen sedan into a tuned street weapon mirrors the cultural arc of import-scene tuning described by Wikipedia (2025). For GTA VI, set in the State of Leonida, this system is expected to expand with Floridian-coded muscle, exotic, and offshore-style performance archetypes appropriate to the Vice City milieu (Rockstar Games, 2025).
This report covers the three primary performance upgrade pillars - engine, turbo/forced induction, and transmission - alongside their canonical tiers, their gameplay effects, and their likely evolution from the GTA V baseline.
The engine upgrade (engine level, or "EMS upgrade" in some community guides) is historically the headline performance modification and contributes the largest single-axis boost to acceleration and top-end power. In GTA V, Los Santos Customs offered four engine levels: EMS Upgrade Level 1, 2, 3, and 4, with Level 4 typically gated behind in-game progression and substantially more expensive than the prior tiers (GTA Wiki, 2026). Each step incrementally raises the vehicle's effective horsepower model, which the game's physics simulation translates into faster 0-60 times and a higher terminal velocity, though the curve flattens at the top tier such that the jump from Stock to Level 1 is felt more dramatically than Level 3 to Level 4. This mirrors real-world diminishing returns in naturally aspirated tuning, where each additional unit of power demands disproportionate investment (Wikipedia, 2025).
For GTA VI, a five-tier structure is plausible, potentially splitting the legacy Level 4 into a "Street" and a "Race" variant, the latter unlockable only through reputation with a specialist tuner contact - a pattern Rockstar previously trialled with the Benny's Original Motor Works workshop and the LS Car Meet (GTA Wiki, 2026). Engine upgrades in GTA VI are also expected to interact with a more detailed wear-and-tear or fuel-grade subsystem, reflecting Rockstar's tendency to deepen ambient simulation systems between mainline titles.
The Turbo Tuning modification in GTA V is a binary on/off toggle rather than a tiered upgrade: installation grants a flat acceleration bonus and the characteristic audible blow-off-valve "whoosh" on throttle lift, which serves as both an auditory reward and an identifier in PvP and racing contexts (GTA Wiki, 2026). Mechanically, the in-game turbo abstracts the real-world forced-induction principle described by Wikipedia (2025), in which a compressor forces additional air into the combustion chamber, raising cylinder pressure and power output beyond naturally aspirated limits, with attendant risks of detonation if the air-fuel ratio is mismanaged.
In GTA VI, a graduated turbo system - small/medium/large or single/twin-turbo tiers - would align both with community demand and with Rockstar's stated ambition to broaden tuner-culture representation. A tiered turbo would enable trade-offs between throttle response (small turbo, low-end torque) and peak power (large turbo, top-end emphasis), introducing meaningful build diversity for racing playlists. Supercharger variants, distinct from turbos in their belt-driven characteristic, could plausibly appear on muscle-car archetypes consistent with the South Floridian setting, paralleling the supercharger/turbocharger distinction noted by Wikipedia (2025).
Transmission upgrades in GTA V spanned Stock, Street, Sports, and Race transmissions, with each tier shortening shift times and adjusting gear ratios to favour faster acceleration through the lower gears (GTA Wiki, 2026). The Race transmission, the top tier, produces the most aggressive shift behaviour and is generally considered mandatory for competitive online racing alongside maxed engine, turbo, brakes, and suspension. Unlike engine upgrades, the transmission's contribution is felt more in launch performance and gear-change cadence than in raw top speed, making it a complementary rather than redundant purchase.
For GTA VI, the four-tier transmission ladder is likely to be retained, possibly with the addition of a "dual-clutch" or "sequential" cosmetic-mechanical variant tied to specific exotic chassis. The interaction between transmission tier and engine/turbo upgrades determines the effective power band: a Race transmission paired with a Stock engine wastes the available shift speed, whereas a fully-tuned engine with a Stock transmission bottlenecks delivery to the wheels - a balancing dynamic that incentivises full-stack investment and supports the economy's currency drain.
Beyond the three primary pillars, the GTA V performance suite included Brakes (Stock/Street/Sports/Race), Suspension (Stock/Lowered/Street/Sport/Competition), Armor (five tiers from no armor through 100% armor plating), Bulletproof Tires, and EMS-adjacent modifications such as Spoilers, which in some vehicle classes contribute marginal downforce-modelled grip improvements (GTA Wiki, 2026). The real-world basis for suspension tuning - stiffer springs, shorter shock absorbers, and stiffer sway bars trading ride comfort for cornering responsiveness - is documented by Wikipedia (2025), and the GTA abstraction preserves this trade-off through reduced body roll and lowered ride height at higher tiers, though without the negative-handling penalties that purely cosmetic stance modifications would carry in reality.
A fully maxed performance build in GTA V / Online commonly required several hundred thousand in-game dollars per vehicle, with super-class cars demanding upwards of $500,000 in upgrades alone, excluding the chassis purchase. This established the performance-upgrade tier system as a core currency sink underpinning the live-service economy (GTA Wiki, 2026). GTA VI is expected to scale this economy upward, potentially introducing modification subscriptions, reputation gates, and rarer parts sourced through dynamic-world activities - an evolution consistent with Rockstar's trajectory of weaving modification economies into broader progression loops.
GTA Wiki (2026) Los Santos Customs. Available at: https://gta.fandom.com/wiki/Los_Santos_Customs (Accessed: 14 May 2026).
GTA Wiki (2026) Vehicles in GTA Online. Available at: https://gta.fandom.com/wiki/Vehicles_in_GTA_Online (Accessed: 14 May 2026).
Rockstar Games (2025) Grand Theft Auto VI - Official Information. Available at: https://www.rockstargames.com/VI (Accessed: 14 May 2026).
Wikipedia (2025) Car tuning. Available at: https://en.wikipedia.org/wiki/Car_tuning (Accessed: 14 May 2026).
Wikipedia (2025) Engine tuning. Available at: https://en.wikipedia.org/wiki/Engine_tuning (Accessed: 14 May 2026).