Not many drivers trust official combined fuel economy figures. They may be achievable in laboratory conditions, but the test cycle doesn’t accurately reflect the way most of us drive. And as for fuel economy when towing a caravan, the official figures are little help at all.
For the past few years, our sister publication What Car? has run a test programme to obtain more realistic economy figures. It’s called True MPG. If you want to know exactly how True MPG works, you can head online to find out more.
So far, only a handful of cars have been tested while towing, but True MPG does at least give a more believable picture of a car’s fuel economy than the lab-based official tests. What Car? has been looking at its results over the past 12 months, and the results make interesting reading.
The Seat Leon 1.6 TDI 110 SE Ecomotive was the most efficient car tested, returning 63.2mpg. However, that’s a long way off the 85.6mpg achieved on the official combined cycle.
The Estate version, which Seat calls the ST, is sixth in the league table with a True MPG figure of 61.5mpg. We’ve towed with the ST (although not the fuel-sipping Ecomotive) and found it is a very stable and practical tow car.
Of these, I’d say the Octavia looks the most likely tow car. It has a kerbweight of 1280kg (including 75kg for the driver), which gives an 85% match figure of 1088kg. The legal towing limit is 1300kg. Don’t forget, the more powerful 2.0-litre was the overall winner at the Tow Car Awards in 2013.
What Car? also took a look at which cars were furthest from their official figures when tested. Surprisingly, some cars appear on the list of most economical cars and the line up of models which were miles off the official figures. The Octavia Greenline III is one, missing its official combined figure by more than 30%. The worst offender was the Ford Fiesta Zetec S R Edition, which returned 39.7mpg when tested when the official combined figure is 62.8mpg.
On the bright side, a number of the cars True MPG tested in the past 12 months came close to matching their official economy. In fact, if you are lucky enough to own an Aston Martin V8 Vantage S, a Vauxhall VXR8 GTS or a Jaguar F-type R, these all beat their official combined figures – albeit only just.
Two sports cars and a V8 saloon aren’t really tow car material. However, the SsangYong Korando SE is an honest budget tug with a 1666kg kerbweight and a 2000kg towing limit. According to What Car?’s True MPG tests, this achieves 46.2mpg, just a fraction down on the claimed figure of 47.1mpg.
The results make fascinating reading as far as they go, but at the moment there are no plans for widespread fuel economy testing of tow cars using True MPG’s sophisticated test kit. From the tests which took place at the Tow Car Awards in 2013 and 2014, we know that fuel economy when towing a caravan weighted to 85% of the car’s kerbweight can be less than half the official combined figure. In our regular towing tests, most cars seem to return 22-30mpg, driven on a mix of A-roads and motorways with a suitably matched caravan in tow.
I’d like to carry out tow car economy tests on a much larger scale in the future, to help you decide what tow car is the right one for you. Watch this space…
Fuel economy when towing can be less than half the official combined figure