Your company needs a car to tow a trailer, but you want to make a green and socially responsible choice.
And of course, you also want to minimise your running costs and tax bill.
Growing numbers of electrified cars are legally approved for towing, often with towing limits that are high enough to handle a large and heavy trailer. So is a hybrid or a fully electric vehicle now a smart choice?
TOWING WITH A HYBRID
As a general rule, both plug-in and self-charging hybrids tend to have lower legal towing limits than similar diesels. The Mitsubishi Outlander PHEV has a legal towing limit of 1500kg, whereas most diesel SUVs of a similar size have a maximum towing figure closer to 2000kg.
However, even with a maximum of 1500kg, there are plenty of trailers the PHEV can legally tow. And you might think it would do so economically, given its official combined WLTP figure of 139.7mpg.
But like any plug-in hybrid, the Outlander’s real-world economy is heavily dependent on its charging and use, and the additional strain of pulling a trailer rapidly eats into battery life.
Earlier this year, The Camping and Caravanning Club carried out a series of towing economy tests on a variety of cars, including the Outlander PHEV. The Mitsubishi’s battery was fully charged, and the fuel tank brimmed. It then towed a caravan weighing 1500kg for an hour on two mile-long, parallel straights, travelling at 60mph on the straights and 40mph on the bends linking the straights. After an hour the car was brimmed again and the fuel economy calculated.
The PHEV achieved 23.4mpg. However, the electric-only range had dropped to zero after just over 17 miles, suggesting a worse figure would have been achieved on a longer drive. For comparison, the diesel cars tested achieved between 26.3mpg and 33mpg on the same route. Not a night-and-day difference, but every diesel tested was more fuel-efficient than the PHEV while towing.
TOWING WITH A BATTERY EV
Theoretically, there are pure EVs approved for towing as much or more than the Outlander PHEV. The Tesla Model X can legally tow 2250kg (although the more affordable Model 3 is limited to 910kg). The Audi e-tron has an 1800kg legal maximum, as does the Mercedes-Benz EQC.
DO I NEED A TACHO?
Even if you are towing with a passenger car rather than a commercial vehicle, a tachometer is required if you are driving a combination of car and trailer with a Gross Train Weight (the combined maximum weights of car and trailer) of more than 3500kg.
There are exemptions for vehicles which stay within 62 miles of their base. You can find more detail here: www.gov.uk/tachographs/tachographs-in-light-vehicles.
It may not be possible to fit a tachograph to all vehicles. Your local Approved Tachograph Centre should be able to offer advice: www.gov.uk/find-approved-tachograph-centre-atc
However, there are practical difficulties to overcome if travelling long distances towing a trailer with an EV. Arrive at a motorway services in need of a recharge, and the driver will need to find somewhere to securely park the trailer before plugging in, because the charging bays won’t have space for a trailer as well as the car itself. A PHEV could simply pull into the forecourt and fill up on petrol or diesel, saving a lot of time and inconvenience.
Then there’s the question of range. The Camping and Caravanning Club tested the all-electric Jaguar I-Pace as well as the Outlander PHEV. It towed a 750kg trailer (the I-Pace’s maximum) for an hour around the same route as the Outlander, and the range before and after the test started were compared with the mileage covered to estimate the car’s range while towing. The result? A range of just 108 miles, compared with the official WLTP range of 292 miles.
So while the I-Pace can tow, the test suggests pure EVs won’t tow very far without needing to be recharged.
THE ‘GREEN’ CHOICE FOR REGULAR TOWING
In the long-run, battery EVs will become better tow cars. But for now, even big and heavy electric cars are best suited to occasional towing over short distances.
Hybrids, either plug-in or self-charging, are a better bet for regular towing. The PHEV’s range doesn’t drop off in such spectacular style when pulling a trailer, and the ease of refuelling makes long journeys far more practical. Plus there are significant National Insurance savings for the company and BiK savings for the driver compared with a diesel tow car.
But don’t dismiss a diesel as the ‘dirty’ choice. There’s strong evidence they will be more fuel-efficient than a petrol-electric hybrid while towing, and the number of diesels that meet the stringent RDE2 emissions test is growing all the time. Long-term, diesel may be on the way out. But for anyone who regularly tows a heavy trailer on business, a modern diesel is still the most obvious choice.