Understeer vs Oversteer in a Kart: Which Is Actually Faster?

By Alessio Lorandi, 2013 CIK-FIA World Champion, KF-Junior. What is in here comes from my Formula 3 debriefs, my own KZ data and the drivers I work with at BabyRace.

The kart doesn’t turn, or the kart turns too much. If you had to pick one, which one would you take?

I take the second one. Give me oversteer every day of my life. Let me tell you why, and what you can do about both.

What is understeer and what is oversteer in a kart?

If you’re going through a corner and the kart is not rotating as much as you want, and it’s going wide, that is understeer. If instead, in the same corner, the kart is over-rotating and pointing you towards the inside with the rear kind of sliding, that’s oversteer.

That’s basically it. We don’t have to over-complicate things. Understeer is when there is not enough rotation. Oversteer is when there is too much rotation.

You can call it whatever you want. “The rear is sliding”, “the front is missing”, “the rear is pushing”. But the thing you’re referring to is a balance issue, and it is either understeer or oversteer.

What does kart balance actually mean?

It’s simply the amount of work each axle is doing through a given corner. If the front axle is doing 90% of all the work and the rear just 10%, you’ll have a massive amount of oversteer. If the rear axle is doing 90% of the work, you’ll have a huge amount of understeer. Both no bueno.

The goal is to get as close as possible to that 50-50 balanced work from front to rear through most of the corners. And careful, I’m talking about work. Weight distribution is another thing.

Is it a front problem or a rear problem?

This is the hardest part. Understanding whether the issue is coming from the front or from the rear.

You may have a perfectly strong rear but a front that isn’t strong enough, so you have understeer. If you then go and make the rear loose, yes, you will have better balance. But you will probably have not enough grip in the front and not enough grip in the rear. Overall you’re very free, as we call it in karting. You’re very loose, but you are not very grippy.

So whenever you have used tyres and the track is slippery, you may struggle. And whenever you have new tyres and the highest grip, maybe you’re going to excel.

But figuring out front or rear is the second priority. The number one priority is always to understand whether you have understeer or oversteer in terms of balance. Then we work on the front end or on the rear end. That is what all the engineers are looking for, also when you are in formula cars.

My mechanic in karting worked the same way. If I was struggling with understeer, he wouldn’t just ask me where. Slow corners or fast corners, entries, mids or exits. He wanted me to help him understand if it was a front related issue or a rear related issue. Because with understeer you may have too little front, or you may have too much rear. And most of the times it’s the driver who needs to feel that. It’s hard for the mechanic.

How do you rate your balance corner by corner?

I remember when I was in Formula 3 for the first time, my engineer would ask me to fill up a paper every session. How much understeer or oversteer I had in every corner, in the entry, mid and exit phase. We had a one to five scale.

So I could say three out of five understeer on entry, two out of five understeer in the mid corner, and maybe three out of five oversteer on exit.

Why is giving feedback a skill of its own?

That sheet was interesting because it forced you to be self-aware of what was happening in the car. At first I wasn’t very good at it. My teammate, Charles Leclerc, was way better at it. He had one year more experience, and he could be a bit more specific than I was. So I had to learn from him.

In karting I wasn’t doing that. With my mechanic I would say: “I have a bit of entry understeer, the exit is okay, the mid corner is okay.” Quite vague.

And engineers in Formula 3, Formula 2 or Formula 1 don’t like that sort of mediocre feedback. They want highly specific feedback. If they’re going to improve the car, they need to know your feeling on the car and what needs to be changed to go faster.

So you need to be very good at giving feedback. And if you are not right now, you have to learn how. That’s a skill of its own.

How do you build it? Take a track map, list entry, mid and exit of every corner, and rate from one to five how much understeer or oversteer you have. I get my kids at BabyRace to do it every session. I wish somebody had given me that structure when I was in karting.

What does understeer actually cost you?

With understeer there’s going to be less rotation than you were expecting and hoping to get. That’s bad most of the time. Because if you cannot get the rotation, you have to wait to go on the throttle.

And if you still try to go on the throttle carrying the same speed you would with a neutral balance, it’s basically going to send you out. You’ll push wide, you’ll have to back off on the exit, or you’ll probably go in the grass.

Why is steering angle on the exit so expensive?

Because when you have too much steering angle, it essentially becomes drag. The front is acting as a brake.

I saw it on my own data. I was racing in Franciacorta for the world championship, in a shifter with 52 horsepower. Whenever I had understeer, I could see that the speed was picking up less in the exit of the corners. If I had to wait with more steering on the exit, my exit speed wouldn’t pick up as well as when I had better rotation in the mid corner and less steering angle.

And I was like, wow. If I feel it and I see it on the data with 52 horsepower and gears, then it’s really a priority for the lower power karts like Mini or Junior. In 60 Mini you have very little power. Too much steering angle in the mid to exit phase is quite deadly there.

With a high power kart there’s one more thing. If you go from understeer and you try to pick up the gas abruptly, you’re going to get snap oversteer. Because you had understeer first.

So every time I spot some understeer in my data, I instantly free up the rear and add more front. As simple as that. When you’ve got 5 degrees more steering angle coming out of a corner, your exit speed will be so much worse than if your steering was more straight past the apex.

How do you fix understeer while you are still driving?

If you have understeer, it’s key that you fix it on the setup side. But you can also fix a lot of it with the driving. Not everything. The entry to mid corner phase you can definitely improve. The exit specifically will be quite hard.

The way to reduce understeer on entry, and at least put a patch on it, is to create more rotation with the brakes. A little bit harder, a little bit more aggressively, and trailing them more. Whenever you trail the brakes, you shift the weight more to the front and a little bit lower. When you do that you create more pitch and more rotation.

So if you feel like there’s not enough rotation and you’re at 80% of your braking capacity, get to 100% of your braking capacity. You will get more rotation, and that’s going to help you point the kart exactly where you want it in the mid corner.

And when you do a proper rotation on entry to mid, the exit will almost always come as a consequence.

That’s what I always tell my drivers. You have understeer. All right. We cannot change the setup when we’re driving. So what can you do with your pedals to get more rotation? You can get more rotation with the brakes. Then go out and do it.

One thing to watch. If you’re oversaturating the front tyres, you may actually have to be off the brakes a bit earlier. If that’s not the case, loading the front and carrying more entry speed generates really good rotation.

And a fast corner where you don’t use the brakes? In that case you’re kind of screwed.

What else can you do from the seat when the kart won’t turn?

You don’t generate rotation only with the brakes. You also generate rotation by carrying more speed.

In karting you can also use the body a little bit. You can lean out if you need more rotation. I don’t necessarily recommend using your body as a strategy. But if it’s slippery in the morning, or slippery for the first couple of laps, you can’t change the setup for those two laps. You can’t make a dynamic setup. So there you can generate a bit of rotation by being a bit more aggressive.

Those first laps are also where a lot of understeer is made. On a formation lap or a preparation lap in a shifter I try to be very gentle on the throttle and I push the fronts a lot on the braking. Because if the rears are ready and the fronts are not, you will have understeer. And I just hate having understeer.

For the exit, think about the line. If you want less understeer on the exit, you’ve got to have a later apex and a driving style that rotates the kart nicely on the entry to mid corner. So on the exit you have less steering angle.

And if it’s a tiny bit of understeer, say the first session of the day and it’s a bit cold, you can use a tiny bit more steering wheel in the mid corner. That’s another way to generate rotation. But you don’t want to use too much. In karting, if you’re turning too much, it’s just going to make everything worse.

Is it the kart, or is it you?

Think about it. Whenever you’re running in an engine, a new piston or a new engine, you’re carrying very little speed in the corners. And it feels like the kart understeers. Because you’re going at low speed and not on the limit, you are not generating the rotation.

With that same setup, when you start to push, you start to generate rotation. And you start to get oversteer.

So if you are not carrying the optimal speed right now, remember that you are not yet generating all the rotation that setup can give you.

Give the same kart setup to two drivers. One aggressive, one very smooth and always driving under the limit. The aggressive driver will report oversteer and the smooth driver will report understeer. The way you drive massively affects the balance of the kart.

In cars there’s way more weight transfer and more dynamic ride height change. When you brake the front pitches forward and the rear lifts up, even with anti-dive and anti-squat. But the driving style is still felt massively in karts too. I’ve seen it happen to me and to every other driver I’ve worked with at BabyRace.

It goes the other way as well. Many drivers are very smooth with the brake pedal and very aggressive with their hands. That results into oversteer. It feels like the kart is sliding, it feels like it’s set up badly. But most of the times the driver makes it slide.

So before you blame the chassis, ask yourself how you drove it.

What do you tell your mechanic after the session?

The session is finished and you’re back with your mechanic.

“Listen, I have understeer four out of five on the entry, three out of five in the mid corner, two out of five on the exit.” Now he knows exactly where to work.

You can even give him setup suggestions, if you both know the kart well. I’d say “now we need to change the axle”, or “we need to give it way more caster”.

With understeer, what would I look at?

• Caster. Add caster. It normally helps you all the way through the corner.
• Front track width. I’m talking about Mini numbers: instead of 98 centimetres you go to 99, so half a centimetre wider per side. You’re going to have more front in the middle of the corner.
• Seat position. If you have so much understeer, the easiest thing is to go forward with the seat, at least one or two centimetres. Try that and you’re going to see the kart change drastically without doing anything else.
• Seat stiffness. If the two rear wheels stay glued to the ground in the mid corner because your seat is too stiff, you can’t get that little lift of the inside rear wheel. That generates understeer, a rear push.

Both more caster and a wider front track give you more likelihood of lifting up the inside rear wheel. I go through the rest in my setup masterclass and in the soft seats vs hard seats guide.

If you learn how to do those two things, the rating and the feedback, you’ll not only get a better setup. You’ll also feel more and better what you’re supposed to do while driving to counterbalance whichever way the balance has gone.

Will the kart ever be perfectly neutral?

No. And this is an important reminder.

You will always have either understeer or oversteer when you’re pushing the limits, and when you’re above them. It’s okay to have one out of five oversteer or one out of five understeer. If you have four out of five, that’s not okay.

Every time you push the limits, especially when you end up making mistakes and going beyond them, you will have some sort of balance imperfection. It’s just normal. It’s never going to be on rails.

The balance is a moving target. Every session it will feel slightly different based on the grip level, the track condition and the tyre wear, despite leaving the kart untouched all day. With 20+ years on track, I gave up the belief that you can get a “perfect” balance. I aim at getting as close to it as possible.

It also depends on the slip angle. Karting has a pretty wide slip angle compared to single seaters, so it’s way easier to be on that slide momentum. You will always be sliding to be fast.

Max Verstappen said the same in a podcast in Brazil. In karting you have to almost always be on the edge of sliding, because the slip angle of the tyre is completely different to a single seater’s. In single seaters you’re not sliding as much. You’re pretty much driving on rails.

So the question is never “how do I get zero”. The question is which of the two you prefer to have a little bit of.

Understeer or oversteer: which is actually faster?

If I have to choose one over the other, I would always pick oversteer over understeer.

The most successful racing drivers of all time, like Schumacher, Verstappen and Senna, would choose the same. I’m not saying I’m one of those. But in karting I feel like I’ve accomplished a lot, as a driver and as a team manager, so I feel I know a thing or two.

The reason is simple. You can control oversteer, but you can’t control understeer.

You can control the kart by turning super smoothly. But you can’t really do anything when you’ve got understeer, besides carrying less speed. Which is what you’ll be forced to do. And so you lose speed.

And honestly, you can carry more minimum speed in a corner with one out of five oversteer than with one out of five understeer. It’s always like that. In the dry, and in the wet a lot too.

How does each one change the way you drive?

When I have understeer I have to drive dirtier. I have to rotate the kart in a forced way which doesn’t feel natural to me. Over-pushing the entry, using my body too much, being quite scrubby on the steering wheel.

When I have a bit of oversteer it helps me. I can carry a lot of speed in the corners while being super smooth with the steering and with my inputs. I can be nice and stable with the body, I can even lean in rather than lean out, and that helps me on the rear as well.

What about a very balanced kart? It’s so easy to make the kart predictable. But most of the time that is not the faster kart, because you have to wait in the middle of the corner for the rotation to come. Say you lose one hundredth of a second in each corner waiting. Over 12 corners that’s 1.2 tenths in a lap.

So every time you have oversteer you can control it more, and you will end up with more minimum and exit speed than if you had understeer.

Why do most drivers still prefer understeer?

Because with understeer you’ve got more stability and predictability, just like driving road cars. So it’s “easier to drive”.

But does it mean it’s faster to drive? Not quite. Setting up a chassis for understeer is a losing strategy.

I was lucky with this. When I was little, like 11, my mechanic taught me how to drive a high rotation kart. I was telling him in Italian “scivola dietro”, it’s sliding at the rear. And he was like, no worries, just keep driving.

He was right. It was tricky at first, but I got used to driving that way. And the moment it was grippy, everybody else struggled with understeer.

Think about it. Every time the track goes from green to grippy, you pick up more rear than front. Always. Because the rear tyres are wider than the front ones.

That’s why to this day I like to drive my setup very aggressive on the front and very loose on the rear. When the track is green it’s super hard to drive. But the moment the track becomes grippy and it’s understeery for the others, to me it becomes just right.

And that’s why I prefer my drivers at BabyRace to be used to driving with oversteer in the training days, so they build the car control and the sensibility. If you always drive an understeery kart, the moment you go searching for more rotation you’re not going to be used to it.

And if you give up after one session of driving with an oversteer setup, you will not succeed.

Why is oversteer scarier in cars than in karts?

In karting this is easy to control. In cars it’s more difficult, because you’re driving at 320 km/h in an F3 or F2 car, close to the walls at tracks like Baku or Macau. At that speed oversteer is a little bit unpredictable and a little bit scary.

That’s why you need a lot of confidence in yourself. And that’s why you need to develop that oversteer perception and those car control skills while you’re still in karting. If you do it late, it’s not going to work. You will not be used to it.

Alex Albon famously said how hard it was to drive the same car as Max Verstappen, because it’s so pointy on the front. The car is super high rotating and super sensitive. One extra degree of steering angle and it becomes unpredictable and easy to crash.

That’s why you need to be a legendary car control driver to make it work. Max drives an aggressive style with a lot of rotation. So Red Bull would develop the car Max wanted, because he’s the one bringing the championships and the wins, and the other driver had to adapt.

But the reality is that it’s not just Max wanting an oversteery car. The oversteering car is the faster car, all the time.

Obviously you don’t want a lot of oversteer. It doesn’t have to be slidy or loose in a way that gives you zero grip. It should be grippy, but with high rotation. That’s the way I like to develop karts as well.

How do you control oversteer?

Remember: when you have oversteer, the only way to control it is by being smoother with your inputs. That’s how you do it in karting.

You have to be more controlled on the brakes. The first steering input has to be very smooth. And you shouldn’t lean out at all, because if you lean out with oversteer you just make it worse. You have to lean in instead. Leaning in keeps the rear more stable.

The brakes work here too, in the other direction. If you have a lot of oversteer, trail the brakes a touch less and be a touch earlier off them. The front raises back up, the rear picks up a bit of weight and more load, and you have a little bit more stability.

And watch your hands in the middle of the corner. If you have too much steering there, you just keep sliding the rear. You start a vicious cycle of corrections and slides, and the corner becomes more and more of a nightmare.

The setup is never going to be perfect anyway. Say the setup is at 99. You adapt your driving to make it 100. Maybe the kart is a little bit oversteery, so you control it by being a little bit smoother.

That’s why in karting the fastest drivers are the smoothest. It’s historically been the case. It’s been the same for me.

Next session, take a track map with you. Rate every corner from one to five, entry, mid and exit. Then go and talk to your mechanic.

Frequently asked questions

What is the difference between understeer and oversteer in a kart?

Understeer is not enough rotation: the kart doesn’t rotate as much as you want and goes wide. Oversteer is too much rotation: the kart over-rotates and points you towards the inside with the rear kind of sliding.

Is understeer or oversteer faster in a kart?

Oversteer, if it’s a little. You can carry more minimum speed in a corner with one out of five oversteer than with one out of five understeer. You can control oversteer by being smooth. With understeer all you can do is carry less speed.

How do you fix understeer in a kart?

From the seat: brake harder, trail the brakes more and carry more speed into the corner. That patches the entry and the mid corner. The exit is hard to fix with driving, so rate each phase from one to five and work on the setup with your mechanic.

How do you control oversteer in a kart?

By being smoother with your inputs. Be more controlled on the brakes, make the first steering input very smooth, and lean in. Don’t lean out, because with oversteer that just makes it worse.

Does leaning out help with understeer?

It can. You can lean out if you need more rotation, for example when the track is slippery for the first couple of laps and you can’t change the setup. I don’t recommend using your body as a strategy.