True MPG: which cars beat their official figures – and which are farthest away?
Our True MPG tests show what fuel economy you can really expect from a car, with some models beating their official figures but others falling more than 20% short...
New cars 5.4% less efficient than official figures
New petrol, diesel and hybrid cars are on average 5.4% less efficient in real-world conditions than the official WLTP figures suggest, What Car? has found.
We put 56 popular models through our independent True MPG test, with the worst performers around 20% down on their official figures, and the best almost 16% up.
WLTP is, however, a lot more accurate than the old NEDC system, which it replaced in September 2018; a previous sample of 159 vehicles type approved to NEDC standards showed an average discrepancy of 20.2% between True MPG and the official results, with the worst performers as much as 40% less efficient than advertised.
To ensure accuracy and repeatability, our True MPG tests are conducted in strictly controlled laboratory conditions, but they are based on a real route that takes in town, rural and motorway driving.
As a result, they reflect what's achievable if you’re driving gently and sticking to speed limits but aren’t resorting to any unrealistically slow acceleration or special 'hypermiling' techniques.
Which of the latest models were farthest away from their official figures, though, and which over-achieved? Let's take a look, starting with the 10 biggest under-performers...
10. Kia Sportage 2.0 CRDi 48V
Official WLTP average 40.8mpg | True MPG 35.7mpg | Shortfall -12.7%
Stick to the lower trims and the Sportage is good value, giving you a lot of space and equipment for your money. It isn't as good at dealing with bumpy roads as the very best family SUVs, though, and the 35.7mpg that this version achieved in our test is rather disappointing for a diesel.
9. Ford Focus 1.5 TDCi 120
Official WLTP average 61.4mpg | True MPG 52.4mpg | Shortfall -14.7%
The Focus stands out as the best driver’s car in the family car class, with handling that truly entertains, and its True MPG of 52.4 is nothing to sniff at, even though it's 14.7% less than the official average. Instead, it's iffy interior quality that slightly lets the car down.
8. Volvo S60 T5
Official WLTP average 38.2mpg | True MPG 32.5mpg | Shortfall -14.9%
Volvo doesn't offer the S60 with any diesel engines; your only options are this thirsty 2.0-litre petrol or an expensive plug-in hybrid. However, the news is far from all bad, because every model is bursting with safety kit, and the seats are some of the best in any car.
7. BMW 1 Series 118i
Official WLTP average 42.8mpg | True MPG 36.3mpg | Shortfall -15.2%
Among today's premium family hatchbacks, the 1 Series is great if you're looking for a classy yet understated interior, and entertaining handling blended with good ride comfort. Unfortunately, you won't get much more than 36mpg out of the 118i petrol version.
6. BMW 3 Series Touring M340i xDrive
Official WLTP average 33.6mpg | True MPG 28.0mpg | Shortfall -16.7%
This is the hottest 3 Series currently available, delivering effortless performance and entertaining handling, plus it's a practical choice in this Touring estate form. Just don't expect it to be a frugal one; we managed a True MPG of 28.0, and you'll see a lot less than that if you drive the car the way it wants to be driven.
5. Volvo XC40 D4
Official WLTP average 42.7mpg | True MPG 35.4mpg | Shortfall -17.1%
The XC40 blends its chunky good looks with space, comfort, cutting-edge safety and relative affordability so ably that we named it Car of the Year back in 2018. In fact, disappointing real-world fuel economy is one of its few weaknesses.
4. BMW 3 Series 320d
Official WLTP average 57.6mpg | True MPG 47.2mpg | Shortfall -18.1%
For many, the 3 Series remains the de facto executive saloon, and it's easy to see why. The latest version is the best-steering BMW of recent times and matches this with stellar body control, yet it still manages to serve up good ride comfort and relaxing refinement. Even its True MPG is decent, despite being well down on the official average.
3. Renault Clio TCe 100
Official WLTP average 54.3mpg | True MPG 44.4mpg | Shortfall -18.2%
As with the 3 Series, the fact that the Clio appears on this list doesn't mean fuel economy is a weakness; we still got almost 45mpg out of it. If you combine this engine with Iconic trim, you'll have a fine small car that's well priced and equipped.
2. Volvo V60 D4
Official WLTP average 49.5mpg | True MPG 40.1mpg | Shortfall -19.0%
The V60 is one of the best executive estates on sale, thanks to great build quality, a comfortable ride and a blooming roomy boot. Just don't be surprised if you buy one and it gets closer to 40mpg than 50.
1. Volvo XC40 T4
Official WLTP average 34.8mpg | True MPG 27.1mpg | Shortfall -22.1%
Like the diesel XC40 we looked at earlier, this petrol version has only one major weakness, and, once again, that's it's real-world economy. The T4's True MPG figure is farther away from its official average than any other car we've fuel-tested to date.
Next, the 10 biggest over-achievers...
10. Citroën Berlingo Puretech 110
Official WLTP average 39.8mpg | True MPG 41.1mpg | Improvement +3.3%
You won’t find a more spacious new car than the Berlingo for less money, whether you need to transport people or haul anything from pushchairs to plant pots. What’s more, it has a soft and relaxed ride that will please passengers, and even this petrol version tops 40mpg.
9. Audi Q5 40 TDI quattro
Official WLTP average 37.7mpg | True MPG 39.0mpg | Improvement +3.4%
This is one of the very best large SUVs you can buy. It's more comfortable and refined than the BMW X3 and puts the Volvo XC60 to shame when it comes to handling and infotainment. The fact that the Q5 beats its official fuel economy in real-world conditions is merely the icing on the cake.
8. Seat Ateca 1.5 TSI
Official WLTP average 42.8mpg | True MPG 44.5mpg | Improvement +4.1%
The Ateca broke new ground for Seat because the Spanish brand had previously built as many SUVs as it had spaceships. However, that lack of experience certainly doesn't show; you get a spacious interior, best-in-class handling and a punchy 1.5-litre petrol engine that can manage almost 45mpg.
7. Volkswagen Polo 1.0 TSI
Official WLTP average 49.6mpg | True MPG 51.8mpg | Improvement +4.4%
All Polos are quiet, comfortable and classy. However, this particular version is also well priced and wonderfully frugal, which is why it's our reigning Small Car of the Year.
6. Peugeot Rifter 1.5 Blue HDi
Official WLTP average 47.9mpg | True MPG 50.5mpg | Improvement +5.4%
The Rifter is basically a Citroën Berlingo wearing Peugeot badges, but while we fuel-tested the Berlingo in petrol form, it was a diesel Rifter that went through our True MPG test, beating its official average by more than 5%.
5. Skoda Superb Estate 2.0 TDI 150
Official WLTP average 51.5mpg | True MPG 54.8mpg | Improvement +6.4%
Skoda's massive Superb Estate occupies the sweet spot between practicality, comfort and value. A range of strong and economical engines, including this 2.0-litre diesel, completes a fantastic all-round package.
4. Dacia Logan MCV Stepway TCE 90
Official WLTP average 44.3mpg | True MPG 47.7mpg | Improvement +7.7%
The Dacia Logan MCV offers lots of room and a surprisingly capable and economical selection of engines, but refinement and equipment levels are poor. It’s a budget option, but this does show.
3. Skoda Karoq 1.5 TSI
Official WLTP average 40.5mpg | True MPG 44.2mpg | Improvement +9.1%
The Karoq is basically the Seat Ateca's less sporty sister, but its more rounded nature isn't necessarily a bad thing. The Karoq offers a more polished ride and superior seating flexibility, for starters. And while the Ateca is officially the more efficient option, in reality it's the Karoq that ekes more miles per gallon out of the turbocharged 1.5-litre petrol engine that both cars use.
2. Mazda MX-5 2.0
Official WLTP average 40.9mpg | True MPG 45.1mpg | Improvement +10.3%
You might think that a sports car would be the last model you'd find on a list like this, but our numbers don't lie – you really can beat the MX-5's official fuel economy by more than 10%. And what a riot the MX-5 is to drive, with nimble handling and performance that seem tailor-made for UK roads.
1. Honda CR-V 2.0 i-MMD Hybrid
Official WLTP average 40.9mpg | True MPG 47.4mpg | Improvement +15.9%
There was a time when hybrids were brilliant in official tests, but disappointing in real-world conditions. However, the CR-V shows that's well and truly in the past, because this practical and refined SUV beats its official mpg by the biggest margin of any car we've tested to date.
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