Forza Horizon 4 Engine Swaps List: All 80 Engines

Forza Horizon 4 lets you take the engine out of one car and put it into another. This page lists 80 of those engine swaps with the car each engine comes from and its stock power. Below the list I explain how to do the swap and how I choose an engine.

One honest note first. I collected this list in 2022. The power is the stock figure of each engine, before any upgrade, and the same engine can show a little more or less depending on the car it goes into. So use the numbers to compare engines, and trust the upgrade screen in your game for the exact figure.

Can you still play Forza Horizon 4?

Yes, if you already own it.

Playground Games took the game off the Microsoft Store and Steam on 15 December 2024, because of licensing agreements. Their official post says players who own it can still download and play it as normal, online included, and that physical copies still work.

I checked Steam on 8 October 2026. The page is still there and it has no price. You cannot buy it. I wrote about the delisting and the free codes when it happened.

The 10 most powerful engine swaps

The 12.8L I6T Diesel from the Volvo Iron Knight starts at 2,400 hp, far ahead of everything else. After it come the 7.4L TT from the Funco Motorsports F9 at 1,750 hp and the 6.7L TT from the Hoonicorn Mustang at 1,400 hp. You will not find those in every car. The game only offers each car the engines that fit it.

Forza Horizon 4 engine swaps list

Each table is sorted from the least to the most powerful engine. "Comes from" is the car the engine belongs to in the game. F4 and F6 are flat (boxer) engines, T means turbo, TT twin turbo and DSC is a supercharger.

Four cylinder and rotary engines

The light engines, 17 of them. They are the ones to look at for a small front wheel drive car or a rally build, because they keep weight off the nose. Two had no donor car in my list: the I4 Motorbike Engine and the 1.6L I4, Turbo Rally.

Six cylinder engines

18 engines, from the 178 hp V6 of the Volkswagen Corrado VR6 to the Racing V6TT of the Hoonigan Gymkhana 10 Ford F-150 Hoonitruck at 914 hp. The famous Japanese straight sixes are here: the 3.0L I6, TT of the Supra and the 2.6L I6, TT of the Skyline GT-R.

V8 engines

The V8 is the biggest group with 24 engines. My list names the last two simply 6.7L TT and 7.4L TT. I put them here because the Hoonicorn Mustang and the Funco F9 are V8 cars.

V10, V12 and W16 engines

19 engines. Big, heavy and loud. These suit supercars and long cars that already carry their weight well. The 8.2L V10 FD from the Formula Drift #43 Dodge Viper SRT10 leads the group at 1,350 hp.

Diesel engines

Both diesels come from racing trucks and carry the same name in the list. They make huge power and they are very heavy, so they are for drag builds and for fun, not for a car that has to turn.

How to do an engine swap in Forza Horizon 4

1. Open your garage and go to Upgrades and Tuning.
2. Choose Custom Upgrade.
3. Open Conversion, then Engine Swap.
4. Pick an engine. The game shows you the new power, weight and PI before you pay.
5. Buy it with credits, then build the rest of the car around it.

Do the swap first. The intake, exhaust, turbo and other engine parts belong to the engine, so if you upgrade the stock engine and swap it later, you pay for those parts twice.

The same Conversion menu also has the drivetrain swap (for example to all wheel drive) and the aspiration swap (turbo or supercharger). The three work together, so look at all of them before you spend.

How I choose an engine

In a real car, the engineer never starts from "how much power can we get". They start from the rules and from what the car can put on the ground. The game works the same way.

• Start from the class. Every race has a PI limit. A swap that takes the car past the limit is useless for that race. Check the PI number before the horsepower number.
• Look at the engine after upgrades, too. The tables show stock power. A modest engine with room for a turbo can end up stronger than one that starts higher. The upgrade screen tells you.
• Watch the weight on the front. A big V12 in a small car adds weight over the front axle. The car gets faster on the straight and worse everywhere else. If the car understeers after a swap, that is why.
• Power you cannot use is slow. With rear wheel drive and 1,000 hp you spin the tyres through the low gears. Either pick a smaller engine or add the all wheel drive conversion.
• Think about the seasons. Britain in this game gets wet in autumn and snowy in winter. A build that works on a dry summer road can be a handful in winter, so I would keep the big engines for all wheel drive cars.
• Use your ears. A swap changes the sound of the car. That is a perfectly good reason to do one.

After the swap the car needs a new tune, because the weight balance and the gearing have changed. My Forza Horizon 4 tips cover the basics, and the difficulty settings page explains the assists that matter once the car has this much power. If you are shopping for donor cars, see the most expensive cars in Forza Horizon 4.

The same lists for the other games: Forza Horizon 5 engine swaps and Forza Motorsport 7 engine swaps. If you have moved to the new game, start from my Forza Horizon 6 guide.

FAQ

How many engine swaps are there in Forza Horizon 4?

This list has 80 engines. That was the count when I collected it in 2022. No car can use all of them. Each car only gets the engines that fit it.

What is the most powerful engine swap in Forza Horizon 4?

In this list it is the 12.8L I6T Diesel from the Volvo Iron Knight, at 2,400 hp stock. The next ones are the 7.4L TT (Funco Motorsports F9) at 1,750 hp and the 6.7L TT (Hoonigan Ford Hoonicorn Mustang) at 1,400 hp.

How do I swap an engine in Forza Horizon 4?

Go to Upgrades and Tuning, choose Custom Upgrade, then Conversion, then Engine Swap. Pick an engine from the ones the game offers for that car and pay with credits.

Why can I not put any engine in any car?

Because the game gives every car its own short list of compatible engines. If the engine you want is not in the Engine Swap menu for your car, it cannot be fitted to that car.

Are the power numbers in this list with upgrades?

No. They are the stock figures of each engine. Upgrades raise them, and the upgrade screen shows the result before you pay.

Does an engine swap change the PI of the car?

Yes. A swap changes power and weight, so the PI changes with it.

Should I swap the engine before or after the other upgrades?

Before. The engine parts you bought for the old engine do not move to the new one, so swap first and upgrade after.

Do I need the donor car to use its engine?

No. You do not have to own the car the engine comes from. You buy the swap with credits in the Conversion menu.

Can I still buy Forza Horizon 4?

Not digitally. It was removed from the Microsoft Store and Steam on 15 December 2024. Players who own it can still download and play it, and physical copies still work.