RHA survey reveals 44-tonne electric HGVs lose 11.8% payload capacity, adding £28,282 annual costs versus diesel equivalents

Battery payload loss is turning the business case for 44-tonne electric HGVs into a structural problem that no amount of clever routing can fix. The RHA’s March 2026 Payload Loss Survey Report — the first rigorous, operator-surveyed study of its kind — quantifies exactly how much battery weight is costing heavy freight operators, and why current UK weight regulations make the problem worse than the technology alone would suggest.

For 44-tonne operations — where the 2-tonne battery derogation does not apply — the economics of electric HGVs are materially worse than diesel. The problem is not energy costs alone: operators must run more vehicles and more miles to move the same tonnage.

Until either regulations shift or batteries lose significantly more mass, this is a policy-created barrier as much as a technology one.

Key takeaways

A 44-tonne electric 6×2 tractor carries 3.3 tonnes less than its diesel equivalent — an 11.8% battery payload loss — because the electric powertrain weighs roughly 3,345kg more.

The existing 2-tonne derogation does not apply to the heaviest 44-tonne articulated combinations, which is exactly where the majority of UK trunking volume moves.

Battery-electric tractors typically weigh 2 to 4 tonnes more than diesel; even where the derogation applies, the entire allowance is consumed by battery weight, leaving a net payload deficit.

Running an electric 44-tonne 6×2 costs £28,282 per year more than diesel; factoring in extra miles to compensate for battery payload loss, total operating costs rise 18.7%.

Batteries are projected to be around 20% lighter by 2040 — insufficient to resolve the payload penalty within UK decarbonisation timelines.

Payload loss

The battery payload loss problem in heavy electric freight is not principally a battery problem. It is a regulatory geometry problem — and the RHA survey is the first piece of industry evidence to make that case with hard operator data from 114 respondents.

The RHA modelled two real Volvo FH vehicles. The diesel 6×2 tractor has a kerb weight of 8,145kg. The electric equivalent comes in at 11,490kg. Both are plated at 44,000kg gross. With a standard 7,500kg unladen trailer, the diesel combination yields 28,355kg of payload; the electric 25,010kg. That 3,345kg gap is not recoverable through better routing, smarter scheduling or clever contracting. It is structural, baked into the vehicle and 57% of operators said they cannot complete half their deliveries with a 22,000kg payload.

Configuration                         Derogation?             Payload loss             Extra annual cost    Total cost

Electric 6×2 (44 tonne)         ✕ Not applicable      11.8% (3,345 kg)      £28,282 pa              +18.7%

Electric 4×2 (40 tonne)         ✓ applies                    4% (1,035 kg)           £15,738 pa             +10.4%

Diesel 6×2 (44 tonne)            n/a                              None                         Baseline                  Baseline

Electric 6×2                            ✓ proposed fix           Near zero                 -£1,855 pa*           −1.2%*

(46 tonne proposed)

*Projected saving assumes payload parity and depot electricity at £0.25/kWh. Source: RHA Payload Loss Survey Report, March 2026.

For the 4×2 configuration, where the 2-tonne derogation applies, battery payload loss shrinks from 11.8% to 4%, and the annual cost premium drops from £28,282 to £15,738. The derogation demonstrates that regulatory adjustment directly improves commercial viability. But it was not extended to six-axle 44-tonne artics, which dominate British long-haul trunking.

The cost arithmetic compounds relentlessly. Annual diesel fuel cost: £47,117. Annual electric charging cost adjusted upward by 11.8% for extra trips: £63,080. That £15,963 energy gap then multiplies through additional driver hours, tyre wear, and maintenance. In a 2% margin sector, an 18.7% cost increase is not a rounding error.

Why payload loss matters

The UK has over 534,100 HGVs on its roads. Fewer than 1,000 are electric. The RHA report lands at a moment when the government is consulting on a

new heavy vehicle CO₂ emissions framework that would mandate phase-out of all new diesel- or gas-powered HGV sales from 2040. If the economics of the transition are structurally broken for the heaviest vehicles — which carry the largest share of freight by volume — the phase-out timeline does not become greener. It becomes fiction.

If weight limits remain unchanged, operators wanting to move the same tonnage with electric trucks must run more vehicles. That means more drivers (the RHA forecasts 60,000 new HGV drivers needed per year for five years), more road movements and more congestion.

This is also directly relevant to hydrogen. As I have argued in Hydrogen HGV Decarbonisation UK, battery payload loss is precisely where hydrogen drivetrains hold a structural advantage: hydrogen fuel cell tractors add approximately 1,000kg to 1,200kg to kerb weight versus 2,400kg to 4,500kg for battery systems at comparable range. At fleet level, that means 5% to 8% more vehicles needed versus 15% to 25% for battery electric.

Three constraints behind payload loss

The RHA identifies three overlapping constraints, each of which needs to be addressed independently for maximum weight electric operations to become commercially viable.

The 2-tonne derogation does not extend to six-axle artics, so battery weight directly reduces payload with no regulatory relief.

RHA ask: raise GVW to 46 tonnes.

Drive axle limits remain at 10.5 tonnes, unchanged from the diesel era. Battery mass concentrates around specific axles, so operators hit the axle limit before the gross weight ceiling.

RHA ask: raise to 12.5 tonnes.

Three-axle electric tractors need a longer wheelbase for batteries, but this breaches length regulations or turning-circle requirements, forcing operators toward underpowered 4×2 configurations.

RHA ask: technical review.

Operators are trapped between a vehicle that is too long for the rules and one that is too light for the job. This is not an engineering failure; it is a regulatory mismatch.

What the industry is getting wrong

Two things. First, the debate has been dominated by energy costs and range — both legitimate concerns, but neither is the binding constraint at the 44-tonne end of the market. Battery payload loss is. The survey shows 74% of deliveries could theoretically be completed within a 300-mile electric range if charging existed at the delivery point. Range is largely solvable with infrastructure. Battery payload loss is not solvable without either better batteries or different rules.

Second, the “wait for lighter batteries” argument is weaker than it sounds. The RHA cites University of L’Aquila research projecting approximately 20% mass reduction in battery technology by 2040. A 20% reduction in a 4,500kg battery pack saves 900kg — helpful, but not sufficient to close the 3,345kg battery payload loss gap within UK decarbonisation timelines.

The RHA’s survey is not a complaint. It is a measurement. The question now is whether the response will be proportionate to what has been measured.

Tim Harper, founder and chair, Deep-Tech Commercialisation