4x2 vs 6x2 Tractor Units: Which Is Right For Your Work?
4x2 or 6x2 tractor unit? How weight limits, tyre costs, fuel use and manoeuvrability compare, and which axle layout suits your UK haulage work.
One of the first choices when buying a tractor unit is the axle configuration. The two you will see most often in the UK are the 4x2 and the 6x2. The right one depends on what you carry, where you deliver and how you want to balance running costs against payload.
What The Numbers Mean
The first number is the total number of wheel positions and the second is how many are driven. A 4x2 has two axles with one driven. A 6x2 has three axles, still with only one driven. The extra axle on a 6x2 is usually a lift axle that can be raised when the truck is running light.
Weight Limits
This is the biggest difference.
- A 4x2 tractor unit with a tri-axle trailer makes a five-axle combination, with a maximum gross train weight of 40,000 kg.
- A 6x2 tractor unit with a tri-axle trailer makes a six-axle combination, which can run at up to 44,000 kg when the other conditions in the regulations are met.
If your loads are regularly heavy, such as steel, aggregates, drinks or building materials, the extra 4 tonnes of a 6x2 can make a big difference to every load you carry.
Why Choose A 4x2
- Lower purchase price on the used market.
- Lighter tare weight, which helps on volume work where you run out of space before weight.
- Fewer tyres to buy and lower maintenance costs.
- Tighter turning circle and easier to place in busy yards and town-centre deliveries.
- Often a better choice for curtainsider, box and fridge work that rarely reaches 40 tonnes.
Why Choose A 6x2
- Legal to run at 44 tonnes on six axles.
- Load spread over more axles, which reduces axle overloads on part loads.
- The lift axle can be raised when empty to save tyre wear and improve traction.
- Better suited to tipper, bulk and heavy general haulage work.
- Strong demand on the used market, which helps resale value.
Mid-Lift Or Rear-Lift
On a 6x2 the third axle can sit in front of the drive axle (mid-lift) or behind it (rear-lift or tag axle). Mid-lift is the most common layout in the UK for general haulage. Some lift axles also steer, which reduces tyre scrub and helps when turning. When you view a truck, check the lift axle raises and lowers properly and look at the tyre wear on it.
Our Quick Guide
- Mostly volume loads, multi-drop or town work: a 4x2 usually makes more sense.
- Regular heavy loads, bulk or tipping work: a 6x2 is usually worth the extra cost.
- Mixed work: a 6x2 mid-lift gives you the flexibility to take heavier jobs when they come up.
Still unsure? Read our used tractor unit buying checklist, browse our used tractor units for sale, or tell us what you carry and we will suggest the right specification.