Comparison · 4×2 tractor unit · long haul at 19.3 t

Mercedes-Benz Arocs, 375 kW, 4x2 tractor unit vs Volvo FM, 375 kW, 4x2 tractor unit (2019–2023)

Mercedes-Benz Arocs, 375 kW, 4x2 tractor unit

2020–2023 · 375 kW

34.5l/100 km

median; 29.9–40.9 across 47 declared configurations

Volvo FM, 375 kW, 4x2 tractor unit (2019–2023)

2019–2023 · 375 kW

31.4l/100 km

median; 28.1–39.1 across 68 declared configurations

Mercedes-Benz Arocs, 375 kW, 4x2 tractor unit and Volvo FM, 375 kW, 4x2 tractor unit (2019–2023) side by side
Specification	Mercedes-Benz Arocs, 375 kW, 4x2 tractor unit	Volvo FM, 375 kW, 4x2 tractor unit (2019–2023)
Vehicle form	Tractor unit for semi-trailer (BC)Registered	Tractor unit for semi-trailer (BC)Registered
Axle configuration	4×2Declared	4×2Declared
Registered new	2020–2023Registeredcentral 90% of records	2019–2023Registeredcentral 90% of records
Engine power	375 kWDeclared	375 kWDeclared
Engine displacement	12.8 litresDeclared	12.8 litresDeclared
Gearbox	automatedDeclared	automatedDeclared
Emission class	Not recorded	EURO 6, EURO VI B, EURO VI C, EURO VI D, EURO VI ERegistered
Gross vehicle weight	18,000–20,500 kgDeclaredmedian 18,000 kg, across 113 declared configurations	19,000–23,000 kgRegisteredmedian 21,500 kg, across 14 type-approval versions and 3 records without one
Kerb weight	Not recorded	7,354–8,320 kgRegisteredmedian 7,523 kg, over 18 registrations
Wheelbase	Not recorded	3,700–3,900 mmRegisteredmedian 3,800 mm, over 18 registrations
Overall length	Not recorded	5,890–6,210 mmRegisteredmedian 5,990 mm, over 18 registrations
Overall height	Not recorded	3,400–3,780 mmRegisteredmedian 3,430 mm, over 3 registrations
Declared fuel, long haul	34.5 l/100 km Declaredmedian; 29.9–40.9 l/100 km across 47 declared configurations	31.4 l/100 km Declaredmedian; 28.1–39.1 l/100 km across 68 declared configurations
CO₂ per tonne-km	46.81 g Declaredmedian; 40.54–55.5 g	42.54 g Declaredmedian; 38.1–53.02 g

Fuel and CO₂: long haul at 19.3 t, 2022 declarations.

What the numbers actually say

There is 3.1 l/100 km between these two (9.8%). That is inside the 10% tolerance of declared figures, so on fuel alone neither is the better choice: at 120,000 km a year and an assumed £1.40 a litre the gap would be about 3,720 litres a year (£5,208). The declared figures for one of them alone span 11 l/100 km across its configurations, so the specification ordered matters more than the choice between these two.

Arocs, 375 kW, 4x2 tractor unit full specification FM, 375 kW, 4x2 tractor unit (2019–2023) full specification The fuel ranking

Fuel over a year

120,000 km · assumed price

Mercedes-Benz Arocs, 375 kW, 4x2 tractor unit41,400 litres

£57,960 at the assumed price

Volvo FM, 375 kW, 4x2 tractor unit (2019–2023)37,680 litres

£52,752 at the assumed price

At 120,000 km a year and an assumed £1.40 a litre; the price is an assumption, not one we track.