Data released in January from the Society of Motor Manufacturers and Traders (SMMT) ( shows that diesel demand within the UK new car market declined by 17.1% last year - 1,065,879 diesel registrations in 2017 compared to 1,285,188 registrations in 2016. SMMT chief Mike Hawes put the decline down to “confusing anti-diesel messages [that] have caused many to hesitate before buying a new low emission diesel car”.

Manufacturers use a range of different vehicles both on and off site, including cars for personal use, and vans and lorries for logistic purposes. Another major vehicle within a lot of plants is the so-called ‘factory workhorse’, or forklift truck (FLT).

These machines can be used for a range of jobs such as helping to move materials during production and getting product ready to enter and leave, with firms, for years, being able to take their pick from three main power sources – diesel, electric and gas (LPG). But, what are the pros and cons of diesel FLTs compared to its alternatives, and is FLT diesel demand likely to see a decline, or already in decline, like the UK new car market?

Diesel positives
David Goss, technical manager at the British Industrial Truck Association (BITA), and Peter Harvey, chief executive of the Fork Lift Truck Association (FLTA), say that one positive for diesel FLTs is that they can be very flexible. Goss explains that for outdoor applications, the high output torque, ease of refuelling and moderate operating costs make diesel an “attractive proposition”.

“Electric power has begun to edge out of the warehouse and into rugged heavy-duty equipment in a manner that would have been inconceivable just a few years ago,” he explains. “However, this is a long way from becoming a mass-market solution and initial purchase price is a significant barrier. Battery power will remain dominant in warehouses and other indoor applications, but, faces significant challenges in the traditional domain of the diesel truck.”

While diesels are “noisier than electric drives”, they are also “generally cheaper”, Goss adds. “LPG has the lowest initial purchase cost, but higher operating costs. Refuelling and maintenance is generally simpler for diesels, although electric power is making rapid progress in this regard.”

Harvey reinforces that the diesel is “a truly flexible workhorse”. He reiterates: “The diesel forklift is ideal for outdoor use or indoors in some applications. The diesel truck will also be cheaper to fuel than LPGs, particularly when the user already has diesel fuel on site.
“Cheaper to purchase than electric trucks, they are relatively easy and cheap to maintain and quick to refuel. Perhaps most importantly, they offer a long life with good residual value.”

Diesel downsides
However, as with the automotive market, there are negatives when it comes to diesel FLTs, namely the environmental impact. Harvey says that such powerful performance comes at an “environmental cost.”

“Its exhaust fumes mean it isn’t as suitable for indoor use because of the fume and particulate hazards,” he explains. “However, the presence of particulate filters mitigate the problem somewhat, making diesel trucks appropriate in a wider range of applications.”

In addition, diesel trucks can be bulkier than other truck types and require greater operator skills than electric trucks. “For employers, they raise safety issues around the storage and security of fuel – including clean up after spills – as well as a hot exhaust risk,” Harvey adds. “On some models productivity can also be lost while the operator waits until the particulate filter is clean.”

Goss, however, says that for new equipment, the traditional view of diesel as being dirty and smoky is a thing of the past. “The penalty for cleanliness is an increased maintenance requirement,” he says. “This may be offset by better fuel efficiency, and shouldn’t be a barrier to take up, partly because of the increasing focus on Low Emission Zones (LEZs).

“LEZs, such as that in Central London, only permit the use of equipment meeting strict exhaust requirements. Older equipment does not comply and cannot be used. There is increasing interest in adoption of LEZ in other areas and similar, or even stricter limits, are likely to be applied to specific projects, such as HS2.”

So, is there a diesel decline?
Drum roll please… the simple answer. No. The diesel FLT market has not declined like the UK new car market. Goss analysed BITA’s monthly sales statistics for Orders and Deliveries covering the period 2016-2018 that are available to BITA members.

The statistics show that diesel equipment sales have “maintained volumes, or made marginal gains” compared with LPG and petrol.
“Electric power grabs a lot of headlines, but any growth in that segment hasn’t been at the expense of diesels, at least for industrial trucks,” Goss says. “Although diesel engines in cars have had a bad press in recent years, the fundamental drivers for selecting diesel power for industrial trucks remain very strong. In addition, industry has invested heavily in technology to improve fuel consumption and exhaust emissions, thus maintaining the attractiveness of the proposition.”

Although diesel demand has declined in the UK new car market, it seems that diesel demand within the FLT sector remains strong. These machines are used by a range of manufacturing sites across the UK, and they have various roles that, perhaps, electric and gas cannot fulfil. It’ll be interesting to see where diesel stands in
the next five to 10 years.

BOX: BITA’s David Goss on new fuel types and emissions regulations

Are there any emerging fuel types that could kick diesel FLTs into the long grass?
Last year’s UK government air quality plan identified that environmental concerns relating to diesel engine powered non-road mobile machinery (NRMM) have already been addressed in emissions legislation that is currently in a transition phase. Although the government’s stated ambition to end new sales of conventional petrol and diesel cars and light vans by 2040 is not aimed directly at NRMM, this may have interesting side effects that promote alternative technologies. For instance, development of hybrid drive trucks using a combination of hydrogen fuel cell and lithium-ion batteries would be greatly enabled by automotive infrastructure support.

Is current emissions legislation up to scratch and are there any changes coming into force?
For NRMM there is a major change in emissions regulations looming. The impending requirement is for all internal combustion engine (ICE) powered NRMM to meet the European ‘Stage V’ requirements. The transition arrangements are quite complicated, and last until the end of 2022, but for some new equipment the effective date is 31 December 2018.European manufacturers and reputable distributors are well aware of the requirements, but, anyone importing kit from outside Europe is responsible for making sure that it complies. The European requirements are different from, and in many ways more stringent than, US EPA regulation, for instance .

Will there be an impact on end-users?
Each manufacturer has a different approach to meet the requirements, so there isn’t an easy general answer. Different systems have changing relative merits in different applications. Instead you will need to consider the relative maintenance requirements of each aftertreatment system. However, there is one popular myth that can be laid to rest. Yes, Stage V requires in-service monitoring (ISM), but this is on a very small sample of engines produced, and is the responsibility of the engine manufacturer: there is no additional burden on the truck operator.