By the LetsLease team
This is the oldest three way contest in British car buying. Three premium hatchbacks, three badges people genuinely choose between, and a decision that for most buyers comes down to which one they like the look of.
We went through the current specifications properly and found that one thing almost everyone believes about these cars is the wrong way round. The safety ratings are the opposite of what their reputations suggest.
Quick Verdict
Lease the Audi A3 if you want the safest and most practical of the three. It is the only one with a current five star Euro NCAP rating, it has the biggest boot, it still offers a diesel, and its plug-in hybrid does a remarkable 88 miles on electricity.
Lease the BMW 1 Series if you want the newest car and the only one that offers all wheel drive without making you buy the performance flagship. Be aware that it has the smallest boot by about 80 litres, no diesel, no plug-in hybrid, no manual, and a four star safety rating.
Lease the Mercedes A-Class if the interior matters most to you. It is the oldest car here by a wide margin and it still has the best reviewed cabin and infotainment of the three. Its five star rating, though, is from 2018 and has formally expired.
The Numbers Side by Side
| Audi A3 | BMW 1 Series | Mercedes A-Class | |
|---|---|---|---|
| Euro NCAP | 5 stars, current | 4 stars, current | 5 stars, expired |
| Rating year | Republished 2025 | 2025 | 2018 |
| Adult occupant score | 86% | 78% | 96% (2018 protocol) |
| Boot, mainstream | 380 litres | 300 litres | around 355 litres |
| Diesel offered | Yes, 2.0 TDI 150 | No | Yes, A200d |
| Plug-in hybrid | Yes, 88 miles | No | Yes, around 50 miles |
| Manual gearbox | Yes | No | No |
| AWD without the flagship | No | Yes, 123 xDrive | No |
| Body styles | Sportback and Saloon | Hatchback only | Hatch and Saloon |
| Generation | 2020, facelifted twice | 2024, newest here | 2018, oldest here |
The Safety Ratings Are Not What You Think
Ask most people which of these three is safest and they will say the Mercedes, because the A-Class scored 96 per cent for adult occupant protection and that number has followed it around for years. It is a real score. It is also from October 2018, and Euro NCAP's own datasheet for the A-Class is headed "Rating Expired". Ratings lapse after about six years because the tests get harder, and the A-Class has been reviewed four times since without being retested. A 2018 result is not comparable with a 2025 one.
The Audi A3 is the only one of the three with a current five star rating. Euro NCAP reassessed it and republished the result on 17 November 2025, with 86 per cent for adult occupant protection, 81 per cent for child occupant protection, 76 per cent for vulnerable road users and 74 per cent for safety assistance. Those are 2025 numbers under 2025 tests.
And the result that surprised us most: the BMW 1 Series scored four stars, tested in September 2025, with 78 per cent for adult occupant protection. The detail is more uncomfortable than the headline. Its frontal collision performance scored 8.9 out of 16, where the previous generation 1 Series scored 14.3 out of 16 in 2019. The newest car in this comparison is the lowest rated of the three, and it rates worse in that test than the car it replaced. Australia's ANCAP reached the same four star conclusion.
None of this makes any of them a dangerous car. All three are modern premium hatchbacks with the current generation of driver assistance. But if you are choosing partly on safety, the ranking is the reverse of the received wisdom, and the A3 is the only one that can show you a current five star certificate.
The Boot, and BMW's Misleading Headline
If you search for the 1 Series' boot capacity you will find 380 litres. That figure belongs to the M135 xDrive and nothing else. Every mainstream UK 1 Series has a 300 litre boot, because the 48 volt mild hybrid battery sits under the boot floor and takes roughly 80 litres with it.
So the real comparison is 300 litres for the BMW against 380 for the A3 Sportback and around 355 for the A-Class. That is a meaningful gap in a car this size, and it is the single most practical difference between the three. The A3 Saloon does better again at 425 litres, and if you fold the seats the BMW gives you 1,135 litres against the A3's roughly 1,200.
We will be straight about one thing: the A-Class boot is the hardest figure to pin down in this comparison. Six reputable sources give six different numbers, from 310 to 405 litres, depending on which body, which engine and which measurement. The direction everyone agrees on is that the petrol is biggest, the diesel slightly smaller and the A250e plug-in hybrid smallest of all. We would rather tell you that than pick a figure and present it as fact.
What BMW Has Taken Away
The current 1 Series dropped three things that the other two still offer, and depending on who you are, one of them may end the decision.
No diesel. The 116d and 120d were not carried over, and the UK range is petrol only. The A3 still sells the 2.0 TDI 150, returning 54 to 58mpg, and the A-Class still sells the A200d. If you do serious motorway mileage, that matters.
No plug-in hybrid. There is no PHEV 1 Series at all. Both of the others have one, and the Audi's is exceptional: the A3 plug-in hybrid, badged 40 TFSI e in the UK, has a 19.7kWh usable battery and 88 miles of electric range. That is roughly double what most plug-in hybrids in this class manage and enough that many drivers would rarely start the engine. The catch is practical: it is Sportback only, and the battery cuts the boot from 380 litres to 280. The Mercedes A250e manages around 50 miles.
No manual gearbox. The 1 Series is automatic only, with a seven speed dual clutch. The A3 still offers a manual on the 1.5 TFSI petrols. A small point for most people and a dealbreaker for a few.
What BMW Gives You That They Do Not
One significant thing: all wheel drive without buying the performance flagship. The 123 xDrive has 218PS, reaches 62mph in 6.3 seconds and drives all four wheels, and it is an ordinary trim rather than a halo model. On the Audi, quattro means the S3 or RS3. On the Mercedes, 4MATIC means the AMG A35 or A45 S. If you want a premium hatchback with all wheel drive and no interest in a 300PS performance car, the BMW is the only one of the three that sells you one.
Age, Interiors and a Nice Irony
On paper the lifecycle order is clear. The BMW is the newest, a fourth generation car launched in 2024, though several UK reviewers thought it closer to a heavy facelift of its predecessor than an all new design, and it sits on the same front drive platform. The A3 dates from 2020 but has now been facelifted twice, most recently with orders opening in September 2026, and that update brought a 12.8 inch touchscreen and a new digital dashboard. The A-Class is from 2018, facelifted in 2022, and is plainly near the end of its life, with Mercedes declining to confirm when it finishes and the CLA positioned as its effective replacement.
Which makes the interior verdict faintly ironic, because the oldest car here has the best reviewed cabin. Carbuyer called the A-Class a class leader with "exemplary, up-to-date infotainment" that makes it feel "more modern than its competitors", and Auto Express in June 2026 described a "gorgeous interior" with "very impressive" infotainment. Eight year old design, still winning.
The criticism lands on the BMW instead, and it is about ergonomics rather than software. Parkers judged moving the climate controls into the touchscreen "a step in the wrong direction ergonomically", called the vent controls "flimsy-feeling joystick-type controls" and found the entry level Sport cabin "a little drab". Auto Express noted "a distinct lack of colour in the standard car". One to watch on the Audi: its September 2026 facelift deleted the physical climate controls too, and we have not yet seen a UK review of that cabin, so we cannot tell you whether reviewers will mark it down the same way.
One Thing to Check Before You Sign a Plug-in Hybrid
If you are considering the A3 plug-in hybrid or the A250e as a company car, get the CO2 figure confirmed on the exact derivative before you commit. Published figures for both cars are currently all over the place, and the likely reason is a European emissions standard called Euro 6e-bis, which lowered the share of driving the test assumes is done on battery and roughly tripled the quoted CO2 of plug-in hybrids on new type approvals. Because company car tax is set by CO2, that moves the monthly figure a long way. There is a Treasury easement that treats eligible plug-in hybrids favourably, but eligibility turns on the registration date, the emissions standard and the quoted CO2 itself. We are a credit broker rather than a tax adviser and Benefit in Kind rates change each tax year, so ask us for the figure on the car you are quoted and let your accountant confirm the position.
Which Should You Lease?
The A3 is the one we would put at the top, and that is a conclusion from the specifications rather than a preference. It is the only one with a current five star safety rating, it has the biggest boot, it offers the widest choice of powertrain including a diesel and a manual, it comes as a hatchback or a saloon, and its plug-in hybrid is in a class of its own on electric range.
The 1 Series earns its place if you want all wheel drive on an ordinary trim, or if you simply prefer how BMW's cars drive, which is a perfectly good reason and not one a spec sheet captures. Go in knowing about the 300 litre boot and the four star rating.
The A-Class remains the one to have if you spend more time looking at the inside of your car than thinking about its crash test score, because by common consent it is still the nicest cabin in the class. It is also the oldest and closest to replacement, so if you want the newest thing, it is not this.
Compare A3, 1 Series and A-Class Lease Deals
We are an independent, whole of market broker, so we can price all three against each other on the same terms and tell you which derivative actually fits what you need.
A3 vs 1 Series vs A-Class FAQs
The Audi A3, and it is the only one of the three with a current five star Euro NCAP rating, reassessed and republished in November 2025. The BMW 1 Series scored four stars in 2025. The A-Class has five stars but from a 2018 test that has formally expired, so it is not comparable.
Euro NCAP tested it in September 2025 and awarded four stars, with 78 per cent for adult occupant protection. Its frontal collision score was 8.9 out of 16, against 14.3 out of 16 for the previous generation 1 Series in 2019. Australia's ANCAP reached the same four star result.
The Audi A3, at 380 litres in Sportback form and 425 in the Saloon. The BMW 1 Series has 300 litres on every mainstream UK version, and the A-Class around 355. The 380 litre figure often quoted for the 1 Series belongs only to the M135 xDrive.
Because the 48 volt mild hybrid battery sits under the boot floor and takes around 80 litres with it. Only the M135 xDrive, which has a different installation, gets the larger 380 litre boot.
The Audi A3, with the 2.0 TDI 150 returning 54 to 58mpg, and the Mercedes A-Class, with the A200d. The BMW 1 Series dropped diesel entirely, so the current UK range is petrol only.
The Audi A3, by a wide margin. Its plug-in hybrid, badged 40 TFSI e in the UK, has a 19.7kWh usable battery and 88 miles of electric range, roughly double what this class normally manages. The Mercedes A250e manages around 50 miles. The BMW 1 Series has no plug-in hybrid at all.
Yes, and it is a significant amount. The battery drops the Sportback's boot from 380 litres to 280, and the plug-in hybrid is offered as a Sportback only, not as a Saloon.
All three, but only the BMW offers it without buying a performance flagship. The 123 xDrive has 218PS and all-wheel drive on an ordinary trim. On the Audi, quattro means the S3 or RS3; on the Mercedes, 4MATIC means the AMG A35 or A45 S.
Only on the Audi A3, on its 1.5 TFSI petrol engines. The BMW 1 Series and the Mercedes A-Class are both automatic only.
By common agreement among UK reviewers, the Mercedes A-Class, despite being the oldest car here. Carbuyer called it a class leader with exemplary infotainment, and Auto Express described a gorgeous interior in June 2026. The BMW attracts the most criticism, mainly for moving the climate controls into the touchscreen.
The BMW 1 Series, a fourth generation car launched in 2024, though several reviewers considered it closer to a heavy facelift than an all new design. The A3 dates from 2020 but has been facelifted twice, most recently in 2026. The A-Class is from 2018 and is closest to being replaced.
Yes. We are an independent, whole of market broker placing business across funders including Lex Autolease, Novuna, Ayvens and Santander, so we can quote all three on the same terms and compare them properly. We are a credit broker rather than the lender, so the funder owns the car and holds the agreement with you.