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

Volvo FM, 315 kW, 4x2 tractor unit (2016–2020) vs Volvo FM, 338 kW, 4x2 tractor unit

Volvo FM, 315 kW, 4x2 tractor unit (2016–2020)

2016–2020 · 315 kW
35.1l/100 km
median; 30.3–41.7 across 48 declared configurations

Volvo FM, 338 kW, 4x2 tractor unit

2014–2019 · 338 kW
37.3l/100 km
median; 32.8–39.5 across 28 declared configurations
Volvo FM, 315 kW, 4x2 tractor unit (2016–2020) and Volvo FM, 338 kW, 4x2 tractor unit side by side
SpecificationVolvo FM, 315 kW, 4x2 tractor unit (2016–2020)Volvo FM, 338 kW, 4x2 tractor unit
Vehicle formTractor unit for semi-trailer (BC)RegisteredTractor unit for semi-trailer (BC)Registered
Axle configuration4×2Declared4×2Declared
Registered new2016–2020Registeredcentral 90% of records2014–2019Registeredcentral 90% of records
Engine power315 kWDeclared338 kWDeclared
Engine displacement12.8 litresDeclared10.8 litresDeclared
GearboxautomatedDeclaredautomatedDeclared
Emission classEURO VI B, EURO VI CRegisteredEEV K, EURO 5, EURO 6, EURO V, EURO VI, EURO VI B, EURO VI CRegistered
Gross vehicle weight18,800–22,000 kgRegisteredmedian 21,000 kg, across 27 type-approval versions and 3 records without one18,600–22,000 kgRegisteredmedian 20,500 kg, across 30 type-approval versions and 21 records without one
Kerb weight6,952–11,840 kgRegisteredmedian 7,765 kg, over 72 registrations6,400–7,948 kgRegisteredmedian 7,275 kg, over 73 registrations
Wheelbase3,500–4,000 mmRegisteredmedian 3,800 mm, over 72 registrations3,500–3,800 mmRegisteredmedian 3,700 mm, over 73 registrations
Overall length5,690–6,410 mmRegisteredmedian 6,190 mm, over 72 registrations5,600–6,210 mmRegisteredmedian 5,960 mm, over 73 registrations
Overall height2,900–3,910 mmRegisteredmedian 3,880 mm, over 34 registrations3,170–3,890 mmRegisteredmedian 3,400 mm, over 21 registrations
Declared fuel, long haul35.1 l/100 km Declaredmedian; 30.3–41.7 l/100 km across 48 declared configurations37.3 l/100 km Declaredmedian; 32.8–39.5 l/100 km across 28 declared configurations
CO₂ per tonne-km47.6 g Declaredmedian; 41.1–56.6 g50.6 g Declaredmedian; 44.5–53.6 g

Fuel and CO₂: long haul at 19.3 t, 2019 declarations.

What the numbers actually say

There is 2.2 l/100 km between these two (6.2%). 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 2,640 litres a year (£3,696). The declared figures for one of them alone span 11.4 l/100 km across its configurations, so the specification ordered matters more than the choice between these two.

FM, 315 kW, 4x2 tractor unit (2016–2020) full specificationFM, 338 kW, 4x2 tractor unit full specificationThe fuel ranking

Fuel over a year

120,000 km · assumed price
Volvo FM, 315 kW, 4x2 tractor unit (2016–2020)42,120 litres
£58,968 at the assumed price
Volvo FM, 338 kW, 4x2 tractor unit44,760 litres
£62,664 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.