Mild, full and plug-in hybrids: the differences
Mild, full and plug-in hybrids compared: battery, electric-only driving, charging, economy, 2026/27 tax and where each stands under the 2030 and 2035 rules.
Updated
The difference comes down to how much the electric side can do. A mild hybrid has a small motor that helps the engine but cannot drive the car on its own. A full hybrid can drive short distances at low speed on electric power and charges itself as you drive. A plug-in hybrid has a much larger battery that you charge from the mains, and can cover everyday trips on electricity before the engine starts. For vehicle tax in 2026/27, all three are treated like petrol cars. Under the phase-out rules, mild hybrids count with petrol and diesel from 2030, while new full and plug-in hybrids can be sold until 2035.
The three types side by side
| Mild hybrid | Full hybrid | Plug-in hybrid | |
|---|---|---|---|
| Battery | Small | Small to medium | Much larger |
| Drives on electric power alone | No | Short distances at low speed | Yes, for everyday trips until the battery runs down |
| How the battery charges | Braking and the engine | Braking and the engine | Mainly from the mains, plus braking and the engine |
| Needs plugging in | No | No | Yes, to get the benefit |
| Economy | A little better than the petrol version | Better, mostly in town traffic | Very good if charged often, ordinary on long trips with a flat battery |
| Vehicle tax 2026/27 (registered from 1 April 2017) | £200 standard rate | £200 standard rate | £200 standard rate |
| New sales after 2030 | No, treated like petrol and diesel | Allowed until 2035 | Allowed until 2035 |
The tax column shows the standard rate from the GOV.UK tables. Any of the three pays the expensive car supplement of £440 a year on top, for 5 years from the second payment, if its list price when new was over £40,000.
Mild hybrid
A mild hybrid uses a small electric motor, often combined with the starter and alternator, and a small battery. The motor helps the engine when you pull away and accelerate, lets the engine switch off earlier when you slow down, and recovers some energy under braking.
It cannot move the car on electric power alone. You drive it exactly like a petrol or diesel car, and you never plug it in. The gain in economy is modest.
For a used buyer, a mild hybrid is mostly a petrol or diesel car with extra parts. Check the service history, and ask whether any warning lights relating to the starter-generator or battery have appeared.
Full hybrid
A full hybrid, often sold as a self-charging hybrid, has a larger motor and battery. It can pull away and creep in traffic on electric power alone, over short distances and at low speeds. The engine starts as you speed up or when the battery needs charging.
The battery charges from braking and from the engine. You cannot plug it in. Economy gains are biggest in stop-start town driving, where the car recovers energy each time it slows. On a steady motorway run, the engine does most of the work.
On a used full hybrid, the battery is the part to think about. Our guide to hybrid battery health covers the signs of a tired battery and what a hybrid health check shows.
Plug-in hybrid
A plug-in hybrid has a much larger battery that you charge from a home charger, a public charger or a household socket. When charged, it can cover typical daily trips on electricity before the engine starts. When the battery runs down, it behaves much like a full hybrid.
The quoted economy figure from the WLTP laboratory test includes driving from a charged battery, which is why it can look very high. The Vehicle Certification Agency notes that real results depend on driving style, accessories and load. For a plug-in hybrid, how often you charge matters more than anything. Our guide to buying a used plug-in hybrid explains the checks and costs.
Short trips or long drives?
Match the type to your driving, not the badge.
- Mostly short trips and you can charge at home: a plug-in hybrid can do most of your driving on electricity. A fully electric car may suit you too; see our guide to buying a used electric car.
- Mostly town driving and you cannot charge: a full hybrid gets its biggest gains in stop-start traffic and needs no plug.
- Mostly long motorway runs: a hybrid's battery adds little once you are cruising. A mild hybrid or a conventional car may cost less to buy for similar economy on those trips, and a plug-in hybrid with a flat battery carries extra weight for nothing.
- A mix, with no home charging: a full hybrid is the simpler choice.
Tax for 2026/27
Only cars that run purely on electricity or hydrogen count as zero emission for vehicle tax. Hybrids registered as alternative fuel vehicles used to get a small alternative fuel discount, which ended on 1 April 2025.
For the 2026/27 tax year:
- Registered from 1 April 2017: the standard rate of £200 for 12 months, plus the £440 supplement for 5 years if the list price was over £40,000.
- Registered 1 March 2001 to 31 March 2017: a rate by CO2 band, from £20 for bands A and B up to £790 for band M.
The car tax calculator works out the figure from the V5C details. Our guide to electric car tax covers fully electric cars, which have their own rules.
The 2030 and 2035 rules
The government's response of 7 April 2025 set out what can be sold new after 2030:
- From 2030, new cars that are purely petrol or diesel can no longer be sold.
- Mild hybrids are excluded from the post-2030 allowance, so they are treated like petrol and diesel cars.
- New full hybrids and plug-in hybrids can be sold alongside zero emission cars until 2035.
These rules apply to new car sales. They do not stop you buying, selling or driving a used car of any of these types.
Frequently asked questions
What is the difference between a mild hybrid and a full hybrid?
A mild hybrid's motor only assists the engine and cannot drive the car alone. A full hybrid can drive short distances at low speed on electric power. Neither needs plugging in.
Do mild hybrids need charging?
No. A mild hybrid charges its small battery from braking and the engine. Only plug-in hybrids are charged from the mains.
Do hybrids pay less road tax?
Not any more. Since 1 April 2025 hybrids pay the same rates as petrol and diesel cars. For a car registered from 1 April 2017, that is the standard rate of £200 for 12 months in 2026/27.
Will mild hybrids be banned in 2030?
New mild hybrids are treated like petrol and diesel cars, so they cannot be sold new from 2030. Used mild hybrids can still be bought, sold and driven.