GT3 is the faster class. GT4 is the one that teaches you more.
That is the short answer. A GT3 is a race car with a lot of downforce and a lot of power. A GT4 is much closer to the road car it comes from. It has less of everything, and that changes how you drive it.
I raced GT3 cars in real life. What I say about them here comes from that. What I say about the GT4 comes from the sim.
GT3 vs GT4 at a glance
| GT3 | GT4 | |
|---|---|---|
| What it is | A purpose built race car with the shape of a road car | A road car turned into a race car, with far fewer changes |
| Power | Roughly 500 to 550 hp, depending on the car and its balance | Roughly 400 hp |
| Downforce | A lot. Fast corners are taken on aero | Little. The car leans on its tyres |
| Driver aids | ABS and traction control | ABS and traction control |
| Lap time | The reference | About 9 percent slower. Near 10 seconds at Monza |
| Setup screen | Full: aero, dampers, bump stops, electronics | Shorter. Some parts are fixed or have fewer steps |
| Cars in ACC | The biggest list in the game, base game plus DLC | 11, all in the GT4 Pack DLC |
| Online | Most public servers, leagues and ranked races | Fewer servers, loyal community |
The power and lap time numbers are community figures, not official ones. Balance of Performance moves them from track to track. Treat them as a size of the gap, not as data.
If you are still setting up your first car, the ACC setup guide is the place to start. It applies to both classes.
The real difference is downforce
People look at the power first. The downforce matters more.
A GT3 has a big rear wing, a splitter and a diffuser. The faster it goes, the harder the air pushes it into the track. That is why a GT3 takes a fast corner at a speed that makes no sense the first time you try it. It is also why the car is so sensitive to ride height and rake. I cover that in the ACC aerodynamics guide.
A GT4 has a small wing and not much else. The grip comes from the tyres and the suspension. You feel the car roll, you feel the weight move, and you can slide it without it biting you.
So the two cars ask for different things:
| Phase | In a GT3 | In a GT4 |
|---|---|---|
| Braking | Very hard first hit, the aero helps. Release as the speed drops | Less initial bite. Longer, smoother pedal and more trail braking |
| Fast corners | Trust the downforce. The faster you go, the more grip | The grip you have at 100 km/h is the grip you have at 200 |
| Slow corners | Wait for the car to rotate, then manage the power with TC | Carry speed in. You have little power to get it back |
| Exit | Wheelspin is the risk | A scrubbing front is the risk. Open the steering early |
| Traffic | Dirty air costs front grip behind another car | Almost no dirty air. The slipstream is strong, so packs stay together |
The braking part catches most people who move from GT3 to GT4. They hit the pedal as hard as in the GT3 and the car does not stop the same way. The ACC braking guide explains the release, and it matters even more without aero.
How big is the lap time gap
About 9 percent, by the usual community estimate. A 1:46 in a GT3 at Monza becomes roughly a 1:55 or 1:56 in a GT4.
On a long track that is 10 seconds or more. On a short one it is 7 or 8. In a mixed class race the GT3 leaders reach the GT4 field quickly, so learn to be lapped and to lap before you join one.
Setups: GT4 is simpler
Both classes share the same tabs in the setup screen. The GT4 has less to change inside them.
- Aero: on a GT4 it is mostly the rear wing. There is no aero platform to protect.
- Dampers and suspension: depending on the car, some adjusters are fixed or have fewer steps.
- Electronics: both have ABS and traction control. How TC behaves is in TC1 vs TC2 in ACC.
- Tyres: the same hot window in the dry, 26.0 to 27.0 psi. The ACC tyre pressure guide shows how to hit it.
In a GT4, pressures, wing, brake bias and a sensible TC level get you most of the way. In a GT3 the setup can find you a second. In a GT4 the driver finds it.
That is a good thing if setups bore you. It is also why GT4 lobbies are close: nobody is winning with a magic setup.
The GT4 cars in ACC
The GT4 Pack came out in July 2020 as paid DLC. It adds 11 cars from the GT4 European Series, with a GT4 season in the championship mode.
| Car | Layout |
|---|---|
| Alpine A110 GT4 | Mid engine |
| Aston Martin Vantage GT4 | Front engine |
| Audi R8 LMS GT4 | Mid engine |
| BMW M4 GT4 | Front engine |
| Chevrolet Camaro GT4.R | Front engine |
| Ginetta G55 GT4 | Front engine |
| KTM X-Bow GT4 | Mid engine |
| Maserati MC GT4 | Front engine |
| McLaren 570S GT4 | Mid engine |
| Mercedes-AMG GT4 | Front engine |
| Porsche 718 Cayman GT4 Clubsport | Mid engine |
Without the pack you cannot drive them. GT3 cars come with the base game, and the later packs add more. The full roster is in the ACC cars list.
The layout changes the car more in GT4 than in GT3, because there is less aero to cover it up. A front engine car is stable and likes to be braked in a straight line. A mid engine car turns in faster and punishes a late lift. More on that in front, mid and rear engine cars in ACC.
Online: where the races are
Most of ACC online is GT3. Public servers, Competition servers, leagues, ranked platforms: the big grids are there.
GT4 has fewer servers. The ones that exist tend to be clean, because the people in them chose the class on purpose. Leagues and ranked platforms run GT4 series as well, so check the schedule before you decide there is nothing to race. The ACC multiplayer guide covers where to look.
The game also lets you save one preferred car for each kind of server: GT3 only, GT4 only and mixed. Set both and quick join puts you in the right one.
Which one I would start with
If you own only the base game, GT3. Pick one stable car and stay with it. The ACC car choice guide helps with that.
If you own the GT4 Pack and you are new to sim racing, I would spend the first weeks in a GT4. In karting you learn to carry speed because the engine will not give it back. A GT4 teaches the same lesson. When you move to the GT3 after that, the downforce feels like a gift.
If you already race GT3 and feel stuck, do a week of GT4. It shows you where you are over driving.
FAQ
What is the difference between GT3 and GT4 in ACC?
GT3 cars have more power and far more downforce. GT4 cars are closer to road cars, slower, and simpler to set up.
How much slower is GT4 than GT3 in ACC?
About 9 percent by the usual community estimate. That is close to 10 seconds a lap at Monza.
Do you need DLC for GT4 cars in ACC?
Yes. All 11 GT4 cars are in the GT4 Pack.
Do GT4 cars have ABS and traction control in ACC?
Yes. Both classes run with ABS and traction control, like the real cars.
Is GT4 easier to drive than GT3?
It is easier to catch when it slides. It is not easier to be fast in, because there is less power and grip to cover a mistake.
Can GT3 and GT4 race together in ACC?
Yes. Servers can run mixed class grids, and you can set a preferred car for those.
Are tyre pressures different for GT4 in ACC?
Not in the current game. The dry window is 26.0 to 27.0 psi hot for both classes.