Diesel dominates freight conversation so completely that many operators forget how much petrol their business actually burns: the car-derived vans, the pool cars, the site generators, the groundskeeping kit, the forklift’s gas bottle’s petrol cousin in the workshop. Since September 2021, the standard grade of petrol at UK forecourts changed - and while the switch passed quietly for most, the edge cases sit squarely in fleet territory. Here is what E10 actually is, what it does to fuel economy, and which vehicles and equipment need the older blend.
Standard grade (95 octane) petrol became E10 in Great Britain in September 2021, with Northern Ireland following in November 2022. The name is the recipe: E10 contains up to 10% renewable ethanol, replacing E5’s up to 5% - a doubling of the bio-component, introduced to cut the carbon dioxide emissions associated with petrol vehicles. At the pump there is no ambiguity: petrol pumps clearly label the fuel as either E10 or E5.
The headline compatibility figures are reassuring: almost all - 95% - of petrol-powered vehicles on the road today can use E10, and all cars built since 2011 are compatible. But fleet managers should flip the statistic and look at the other five percent, because that is where fleet vehicles disproportionately live. Older vehicles, classic and cherished vehicles kept for promotional or heritage work, and - critically - a lot of petrol-powered equipment: generators, mowers, saws, older forklifts and small plant. Equipment engines are often older designs, run infrequently, and store fuel for long periods - the exact profile that dislikes higher-ethanol fuel.
The Department for Transport provides an E10 vehicle checker for cars, motorbikes and mopeds, and it takes seconds per vehicle. Any fleet still running pre-2011 petrol vehicles should spend an afternoon with it; the answer goes on the vehicle file and ends the debate at the fuel card.
Vehicles and equipment that are not compatible with E10 are not stranded: they can still use E5, which remains available as the “super” grade (97+ octane) petrol at most filling stations. The operational cost is the price premium of super grade and the occasional hunt for a station that stocks it - a minor logistical fact worth noting for equipment that runs all day, where a five-litre can of super is now a planned purchase rather than an afterthought.
Ethanol carries less energy than petrol, so E10 slightly reduces fuel economy. The official figure deserves to be quoted precisely because it kills the rumour mill: you may see a reduction of around 1%, unlikely to be noticeable in everyday driving. One percent is not a fleet-costing crisis - it is noise compared to tyre pressures, driving style, payload and route planning. Any driver claiming the new fuel has gutted their range should be shown the figure and then the telematics.
For equipment that sits, the more practical issue is storage: higher-ethanol fuel absorbs moisture over time, which is why the guidance’s compatibility concern and the old mechanic’s habit agree - do not leave fuel standing in seasonal equipment, and run it through rather than parking machines with full tanks for months.
E10 compliance is an afternoon’s work, done once. Audit every petrol asset - vehicles and equipment - against the vehicle checker where it applies, and by age and manufacturer guidance where it does not. Mark the small minority that need E5 super grade and put that on the fuel card notes and the equipment labels. Update any fleet fuel policy that still references unleaded without grade, so drivers and operators know which pump to use. And bin the myths with the 1% figure: the fuel economy effect is real but negligible, the compatibility issue is real but small, and both are manageable with a list and a label.
One detail worth getting right in any fleet documentation: the change did not happen everywhere on one date. Great Britain moved its standard grade to E10 in September 2021, while Northern Ireland followed in November 2022. Fleets operating across both - or keeping fuel records for equipment that travels - should date their compatibility audits accordingly, since a vehicle audited against E5 forecourts in Belfast before that later date was audited against a different standard than the same pump today.
Because fleets are audited by reality, not by headlines. The generator that will not start on a Sunday because it was filled from the wrong can, the older van with degraded fuel lines, the insurance-relevant question of whether the right fuel was used in the damaged equipment - these are small risks, and they are all eliminated by knowing which assets are in the five percent. The ninety-five percent of your petrol fleet needed nothing from you. The five percent needed one afternoon. That is the whole job.