Earlier this month, Fleet News highlighted an American study that for the first time pinpointed how diesel exhaust fumes cause allergies and respiratory diseases.
However, this has not deterred a headlong rush for diesel among fleets, and the overwhelming majority of fleet decision-makers see the trend continuing.
Scientists in Cincinnati found that the PM-10 particulates in diesel fumes release compounds in the lungs that make the immune system produce chemicals which cause inflammation. The particulates also shut down part of the immune system that is normally triggered by bacterial and viral infection.
The Government has already factored the suspected negative impact of diesel emissions on local air quality into vehicle taxation, imposing a three point penalty on diesel cars in the new company car tax system, and weighting Vehicle Excise Duty against diesel.
But only half a dozen panel members said the new research would lead them to reconsider a pro-diesel stance, with liquefied petroleum gas the likely winner for 'green' focused drivers with concerns about diesel.
The majority claim that health scares surrounding diesel are nothing new, and that scientific research is frequently contradictory – remember the cancer scares involving leaded petrol and then the benzene content of unleaded petrol.
Above all, however, panel members want clarification from the Government, rather than scientists, about the 'cleanest' road fuel.
From a global perspective, the economy of diesel engines means they consume less of the earth's precious resources, and produce lower levels of carbon dioxide - the worst greenhouse gas.
From a local air quality perspective, unleaded petrol and gas seem to produce cleaner emissions. The emissions-based company car tax system favours diesel so heavily that panel members accept that their drivers are as concerned about their financial health as their physical health. They see no sign of drivers opting to pay more tax for a notionally cleaner petrol-powered car.
Add in the development of particulate filters and major progress in diesel technology, and the wholelife cost benefits of the fuel and diesel's share of the corporate car market looks set to grow even further.
'Will the link recently established between diesel and respiratory diseases alter the standing of diesel-powered cars and vans on your fleet?'
NO. The new emissions-based benefit-in-kind tax system encourages drivers to choose diesel and there are some excellent clean diesel vehicles on the market. The Government decides what it wants to achieve - reducing global warming or local pollution; with so many U-turns in its policies I don't think there is an easy solution.
Di Rees, business services manager, Leo Pharmaceuticals
NO. Under the new BIK rules there has almost been a trade- off between environment and health by the Government. By basing them on CO2 emissions diesel looks more attractive (even with the 3% excess), but the effect of these particulates is unproved and the environmental damage done by petrol engines could be minimal in comparison to that done to health by diesels.
Darren Hallmark, Bank of Scotland
NO, we will continue to acquire vehicles based on wholelife costs and high mileage drivers will have diesels as a consequence. The real diesel particulate problems come from commercial vehicles, poorly maintained and older engines and exhaust systems. I shall not worry too much about our modern, well-maintained fleet cars unless evidence is found to suggest otherwise.
G.R. Details supplied
NO. We have been running our commercial fleet using bunkered diesel for years. It provides ease of refuelling, lower fuel costs and increased mpg. The recent changes in taxation have also pressured most of our company car drivers to opt for a replacement diesel model.
Joanne Hanafan, fleet manager, King UK
NO, we are considering a change to our company car scheme which will see diesel-fuelled options favoured over petrol. This means that the petrol variant will be graded higher than its diesel counterpart, with the result that drivers would have to pay the cost difference (as a contribution towards the car) each month in order to have the petrol alternative. If both variants were found, cost-wise, to be in the same rental category, the diesel alternative would be provided as a higher specification car, eg an LX upgraded to a GLX, in order to encourage use of diesel.
However, I think we should be concerned about the rush for diesel, as there is an unexplained increase in illnesses such as pancreatitis among drivers of diesel-powered vehicles.
Chris Bates, facilities manager, Lafarge Aggregates
NO. We had an all-diesel policy. Subsequent scientific information indicated that diesel was environmentally detrimental; our policy changed. In the past two years, evidence indicated that diesel was again preferable to petrol. This has resulted in us introducing a preferred diesel policy. Diesel and petrol are polluters and more comparisons need to be made in respect of 'lead-free' petrol.
Richard Warner, company secretary, Seco Tools
NO, but it might be a good idea for Ken Livingstone to consider the introduction of London taxis running on LPG to reduce pollution in the city.
Nick Welch, Pinnacle
NO, pressure from drivers wishing to reduce their cars' CO2 emission levels will prevent it. The average driver is not going to pay more in tax on the basis of the most recent piece of scientific evidence. We have long known about the sharp rise in the number of children with respiratory diseases in the UK, and even the newest cars still give out an initial exhaust plume. This will be a greater issue in a predominantly diesel market.
P.P.F. Details supplied
NO. In the absence of substantial evidence to suggest diesel particulates are radically more harmful than petrol equivalents, our drivers will continue to concentrate on minimising their BIK exposure and select low emission diesel variants. Common rail technology produces excellent results in terms of economy, torque and overall noise but the jury is still out on diesel as a long-term solution. If there is damning evidence that particulates are directly linked to health and welfare this could change dramatically.
Peter Eldridge, fleet manager, Motorcare Holdings
NO. Fossil fuels are good for you, but until the strength of the oil companies is broken or hydrogen power plants become cost-effective and the fuel readily obtainable we are stuck with a choice between two evils.
R.C.L. Details supplied
IT is interesting that the Americans of all people have come up with this information as they do not use diesel cars. Our fleet policy is that company vehicles must be serviced in strict accordance with the manufacturer's guidelines. MoT regulations seem to have done little to take poorly running cars off the road. Perhaps if the Government spent some of the revenue it gets from motorists on motoring issues we might see an improvement in this field.
NO. We are a 100% diesel fleet and will continue to be so. Diesel technology has come along in leaps and bounds over the last 10 - 12 years. Cleaner engines coupled with cleaner fuels ensure that some of the scare-mongering is unfounded. However that can help keep the residual value of our fleet up as other companies decide not to have diesel vehicles.
David Bent, national fleet manager, Fowler Welch
NO. I thought it had been long established that diesel emissions, especially particulates, are harmful to the local environment and aggravate respiratory diseases, while the pollutants from petrol cars impact more on the global environment. As London is introducing congestion charging, greater interest will be generated in alternative fuels. Perhaps this will be the spur needed to get a LPG/CNG infrastructure properly established. It will be a welcome development if gas finally becomes a viable cleaner alternative.
P.B. Details supplied
NO. Many of our cars are on the fleet for up to three years.
Drivers are responding to the changes in the personal tax system introduced by the Government. If this was not intended, then the implications of the tax changes should have been better understood before they were introduced.
David Mullins, Administration Manager, Slough Estates
I think we need to know a lot more about the conditions of the tests.
If the link was established by pushing a rat's head up a truck's exhaust pipe, we'd be less than impressed.
Reg Dixon, Niftylift
RATHER than responding to green issues when choosing low emission vehicles, I suspect that people are protecting their financial rather than physical health. Our drivers generally prefer petrol engines but changed to diesel because of the financial benefits. Some clarity from the Government is needed.
Martin Dowsett, Komori
AFTER the rush into diesel to minimise tax bills, it will be two to three years before changes can be made. I cannot see drivers reverting to petrol vehicles unless further incentives or inducements are on offer. What I find odd are the conflicting signals being put out by the Government. The links between diesel particulates and respiratory problems have long been suspected and yet diesel powered vehicles are being actively promoted by fiscal policy.
Glyn Davies, finance director, Staedtler
NOT until the claim is more firmly proven and not if the particulate filters anticipated in the coming years are as effective as they appear to be. As science tends to recommend one thing one day and the opposite another day, I would prefer to wait for a definitive recommendation before changing our long-term policy.
Ian Smith, group accountant, CpiO
NO, particulate traps already available on some diesel cars will significantly reduce the harm they can cause, so diesel will continue to improve its green image.
The huge difference in mpg between diesel and LPG vehicles removes real incentive to go down that green path, unless LPG can be bunkered on site, reducing the pump cost by around 25%. The mpg difference against diesel is often omitted in literature and an LPG vehicle is more expensive to operate based on wholelife costs.
Barry Lingard, fleet manager, Leisure Link
IN the near future there will be research carried out that will provide links that unleaded is harmful and the whole cycle starts again. Diesel has been part of our lives for decades and as people are living longer the sceptics will argue that the research is meaningless.
Mick Donovan, group fleet manager, Bowmer & Kirkland
YES, but only to a limited degree. It might encourage our company car drivers to choose LPG rather than diesel.
Carol Green, transport co-ordinator, Anglian Water
FOR my company it was a major decision to consider diesel fuelled vehicles, as we had always been a petrol vehicle fleet. While the CO2 implication to the drivers was an added element in the decision to change to diesel, the deciding factor was based on claims that emissions from diesels have been considerably reduced.
Gill Garrett, Premiere Products