Karting Classes Explained: From Mini to KZ
Mini, OK, OK-N, KZ, KZ2, Rotax, DD2… Anyone approaching karting faces an alphabet soup of acronyms that seems designed to confuse. Let us sort it out once and for all, without unnecessary jargon.
Karting classes fall into three big worlds: Italian national classes (governed by ACI Sport), international classes (CIK-FIA) and the various one-make championships such as Rotax. We explain them all with real ages and licences; the exact 2026 data is in the ACI Sport yearbook, the official source we start from.
In short Karting classes are divided into ACI Sport national classes, CIK-FIA international classes and one-make series such as Rotax. The first choice is between direct drive (Mini, OK, OK-N) and gearbox (KZ, KZ2). You start from your age and level, using the official data in the ACI 2026 yearbook.
First distinction: direct drive or gearbox?
Even before the acronyms, there is one division that explains everything. Direct drive: the engine has no gearbox and drive goes straight to the wheels through the chain; you accelerate and go. Mini, OK-N, OK and almost the whole Rotax ladder are direct drive. Gearbox: the engine has a gearbox. More power, more torque, more driving technique. KZ and KZ2 are gearbox classes.
A curious middle ground is the DD2 (Rotax): it has two gears but the transmission is direct, without a chain. More on this below.
Karting classes in Italy: ACI Sport (2026)
These are the classes of the 2026 ACI Karting Italian Championship, in order of progression:
MINI Gr.3 (and Under 10). The entry door for the youngest, direct drive. The Under 10 class is reserved for drivers born from 1 January 2016. National Mini licence (or International G).
OK-N Junior. Direct drive for juniors, the step above Mini. National G licence (or International G).
OK-N. “Senior” direct drive in its national version: high performance but lower costs than international OK. National F licence (or International F).
KZ2. The gearbox class: the flagship class at national level. Within it there are KZ2 Under 18 (born from 1 January 2008) and KZ2 Master (born up to 31 December 1990) standings. National E licence (or International E).
Exact ages, minimum weights and licence grades are set every year by the ACI Sport yearbook: check them there before entering, because they can change from season to season.
CIK-FIA international classes
At world and European level, the CIK-FIA classes rule:
OK-Junior. Direct drive, 125 cc liquid-cooled engine. For drivers aged 12 to 14 (G licence from 12).
OK. The “queen” of direct drive: same concept as Junior but for drivers aged 14 and over. Fast, technical, no gearbox.
KZ2. The gearbox class at international and club level: the springboard to KZ.
KZ. The absolute top: 125 cc with gearbox, the true “F1 of karting”. The class of the best.
The Rotax world: a championship of its own
Then there is the whole Rotax universe, which is not a CIK-FIA class but a one-make series with its own National, European and World championships (the Rotax MAX Challenge). Here everyone races with the same sealed engine and the ladder rises from Micro to Mini, Junior, Senior up to DD2 (the only one with two gears). It is often the most accessible and widespread way to race seriously.
We explained the differences between the two top engines of the range here (in Italian): Rotax Senior vs DD2 →
How to find the right class for you (or your child)
Four filters, in order:
Age and licence. They are the first boundary: each class has its own age band and ACI licence grade.
Direct drive or gearbox. You always start with direct drive; the gearbox (KZ) comes later, with experience.
Budget. The higher the class, the higher the running and maintenance costs.
Real ambition. Better to dominate a “lower” class than to struggle in one that is too high.
Golden rule: the class is decided by age, regulations and level, not by the ambition of the moment. A driver who grows in the right class goes further than one burnt out too early.
Frequently asked questions
Which class should a child start in?
Mini (in Italy MINI Gr.3, with the Under 10 class for drivers born from 1 January 2016): direct drive, smooth power delivery, designed for learning safely.
What is the difference between OK and KZ?
OK is direct drive (no gearbox); KZ has a gearbox and is more powerful and technical. OK is the queen of direct drive, KZ the absolute top of karting.
What is the OK-N class?
It is the “national” version of direct drive: performance close to OK but with lower costs. In Italy it is a class of the ACI championship (OK-N and OK-N Junior).
Are Rotax classes CIK-FIA classes?
No. Rotax is a one-make series with its own championship (the Rotax MAX Challenge); the ladder goes from Micro to DD2. It is a parallel world, very widespread and accessible.
Do you need a licence to race, and which one?
Yes. The grade depends on the class and in Italy it is issued by ACI Sport; exact ages and requirements are in the 2026 yearbook. Outside Italy, check with your national federation.
Conclusion
Understanding the classes is the first step to avoid mistakes: it tells you where you can race, with which kart and at what cost. Start from your age and level, choose between direct drive and gearbox, and let the official ACI data guide you, not paddock gossip.
Data checked against: ACI Karting Sporting Yearbook 2026 (classes, ages and licences), FIA Karting (international classes) and Rotax MAX Challenge regulations.
Questions about this topic?
Message us on WhatsApp: we answer personally, with the experience of people who live at the track. And if you want to drive a real racing kart, with Arrive & Drive you get into one of ours, ready on track. The right spare part? You will find it in the shop.
Arrive & Drive Pro by TKS RaceLab: 2026 karts with Rotax Senior MAX and DD2 engines, Alfano 7 telemetry and trackside technical support at Lonato, Franciacorta, Cremona and Ala. Message us on WhatsApp for information and availability.
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Read also: Karting for kids: what age to start and how → · Maranello chassis range: classes and how to choose → · Rotax MAX EVO: classes, power and how to choose →
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Author: Sergio, TKS RaceLab | Published: 5 October 2026
TKS RaceLab is the Italian online store dedicated to karting: spare parts, accessories and everything you need to get on track. With Arrive & Drive you arrive at South Garda Karting (Lonato), Franciacorta, Cremona or Ala and find your kart ready to go. No hassle, just driving.
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