It might be easy to think of company car fleets as being split between private sector businesses and public sector outfits. However, this would overlook the thousands of vehicles on the roads of Britain that are being run by charities, and while the funding may be different, managing them well is arguably among the most important jobs in fleet - allowing their drivers to help disadvantaged members of society, while ensuring that money raised from kind-hearted members of the public is not wasted.

The Salvation Army is one such example. The church and charity offers support to vulnerable and marginalised people from more than 700 centres throughout the UK, has more than 380 charity shops and operates more than 6,500 clothing donation banks. To keep its operations going, it has a fleet of more than 900 vehicles, including nearly 800 cars, along with 78 minibuses, 51 commercial vehicles and 17 specialist catering vehicles. Clearly, running such a sizeable fleet is a major operation, but how does it differ from running a business fleet, if at all? To find out, Business Car visited the charity's Central London headquarters to speak to fleet operations manager Louise Haigh about the role.

She tells us that the majority of the Salvation Army's company car drivers are officers who use the vehicles for their work with the charity's clients, including older people, disabled people and people who are experiencing homelessness.

Haigh says: "It may be picking up their clients, taking them to church, taking them to activities. They will also help with their shopping, take them to hospital, take them to medical appointments."

With this key role played by cars in the officers' work, it is clear they are job-need vehicles, but this doesn't mean drivers are given stringent restrictions about model choice.

"We have got a wide variety of cars," Haigh says. "There are about 12 or 13 different manufacturers, and about 115 different types of vehicles they can choose from in a fleet list.

"They are not offered sports cars, two or three-door vehicles, or four-wheel drive vehicles, but SUVs are fine.

"You do have people that require a larger car for their job. For instance, we have Salvation Army band members who need to carry larger instruments in their cars, so sometimes they need a larger car to accommodate that. 

"We have people working in homelessness services that move people from the centre where they are staying onto their new accommodation - they might take belongings in boxes and a number of people, so they might need larger cars for that. 

"Also, some have got larger families so need larger vehicles - we try to accommodate for the job and their personal circumstances as well."

While the drivers have plenty of choice, one policy that the Salvation Army has in place due to its charity status is a ban on premium brands.

Haigh says: "It is necessary to avoid ostentation like premium-branded vehicles to prevent supporters from believing their donations are being wasted.

"It is a matter of appearance rather than cost. We appreciate some premium vehicles can have very effective whole-life costs but try explaining that to the public at large."

As well as no premium cars, the charity has also banned diesel cars from being driven by officers - not initially because of concerns around 'dieselgate' and air quality restrictions, but because of reliability.

"Originally the fleet was all petrol, and because diesel became more economical, we turned to an all-diesel fleet," Haigh explains. "But then manufacturers started putting diesel particulate filters in the engines, and with that you needed to regenerate the vehicle by travelling for a certain amount of time at the same sort of speed. 

"A lot of our drivers live remotely and couldn't get to regenerate the vehicle on a motorway or major A-road, therefore the engines weren't regenerating correctly, and then the cars were requiring servicing more frequently, and it was becoming very expensive."

The only occasional exception to the diesel ban is for drivers who cover more than 20,000 miles a year, which can apply to the charity's other category of drivers.

Haigh says: "We have got staff who do quite a bit of mileage for the organisation, such as people in property that travel quite a wide distance. 

"Some cover Northern Ireland, Scotland, so it is a huge mileage range. They are mainly the people that take the diesels because of the large mileage they do."

One choice that Haigh works hard to encourage is the adoption of hybrid vehicles, which are incentivised for Salvation Army drivers using a benchmarking system designed to make them more attractive than petrol cars.

"We benchmark on two vehicles, a petrol and a hybrid," she explains. "The petrol is an entry-level Vauxhall Astra. Any vehicle they opt for that is over and above the spec of the benchmark car, they have to pay the additional extra as a monthly or weekly contribution.