Forza Horizon 6 engine swaps are one of the deepest tuning layers in the game because the same chassis can behave, sound and accelerate very differently after a conversion. The problem is that compatibility is car-specific, and a swap that exists for one model may be absent from another model from the same manufacturer. Playground Games maintains a live database for this reason, and Horizon Meets has already added further swap options to existing cars.
Treating Forza Horizon 6 engine swaps as a simple horsepower upgrade usually leads to worse builds. Displacement, aspiration, weight, torque delivery and the class increase all affect whether the conversion actually helps the job you are tuning for. The official table exposes those details alongside every compatible car, which makes it possible to compare options before spending credits and before pushing a build into a class where it becomes less competitive.
Forza Horizon 6 engine swaps menu location
Image credit: Playground Games / Xbox Game Studios
You can access Forza Horizon 6 engine swaps from Upgrades and Tuning, then Custom Upgrade, then Body Kits and Conversions. Only the engines compatible with the selected car appear there. The official Forza database mirrors that car-by-car relationship and lists the engine name, displacement, layout, cylinders, aspiration, base power, torque, possible aspiration conversions and how the car itself is collected.
How to read the official compatibility database
The live Forza Horizon 6 engine swaps table is the safest way to answer whether a specific conversion fits a specific car because Playground Games updates it as new vehicles arrive. Search for the car name first, then compare every Swap row under it. A car with several rows has several engine choices, while a car missing from the swap table should not be assumed to accept a popular conversion just because a similar model does.
Common small-car and rally swap families
Several recurring Forza Horizon 6 engine swaps are aimed at light cars and rally builds. Examples in the official database include the 1.2L and 1.4L motorcycle engines, the 1.6L I3 turbo, the 1.6L I4 Turbo Rally and the 3.2L inline-six. Cars such as the Abarth 595 and BMW 2002 Turbo show how one chassis can move from modest displacement to much more serious output, but the best choice depends on the target class.
V8, V10 and V12 conversions
High-power Forza Horizon 6 engine swaps include familiar 4.0L V8, 5.0L V10, 6.2L V8, 7.0L or 7.7L V12 and racing V12 options across many compatible cars. The BMW M1, modern BMW M cars, Ferraris, Dodges and other performance platforms can have several of these choices. A bigger engine can improve straight-line pace, but the PI increase and changed weight distribution can make a lower-powered option faster on technical routes.
Racing turbo and extreme-power swaps
The official list also contains Forza Horizon 6 engine swaps such as the Racing 3.0L I6T, 4.0L V8 twin turbo, 8.9L V8 displacement-supercharged unit and 7.4L V8 twin turbo. These conversions can start with very high output before further upgrades. They make sense for drag, speed and extreme builds, but they can consume so much PI that tyres, weight reduction or handling upgrades become harder to fit within a class limit.
Aspiration swaps after an engine conversion
Engine choice is only part of Forza Horizon 6 engine swaps because the database also shows permitted aspiration changes. Some naturally aspirated engines can accept a single turbo, twin turbo, positive-displacement supercharger or centrifugal supercharger, while other swapped engines list no additional aspiration option. Checking that column before buying the engine is important if the build depends on a particular power curve or if you are trying to control the final PI.
Collection Journal progress from conversions
Playground Games confirms that using Forza Horizon 6 engine swaps and other conversion upgrades can tick off progress in the Collection Journal. That gives experimental tuning a second purpose beyond lap time. If you are working on Journal completion, it can be worth applying required upgrade types even to cars you do not plan to race long term, then returning to the build you actually want once the completion entry has registered.
How to choose the right engine instead of the biggest one
The useful way to approach Forza Horizon 6 engine swaps is to decide the event and class before buying anything. Road builds benefit from usable torque and space for grip upgrades, rally cars need controllable delivery on loose surfaces, and drag cars can exploit much more power. Use the official live table to confirm compatibility, then preview the class and stats in the upgrade menu. The highest horsepower row is not automatically the quickest complete build.
Official source: Official Forza Horizon 6 Engine Swaps database
