COWERING INFERNO: The truth about DPFs and fire risk
Jump to the class action lawsuit investigation >>
Here’s the best way to burn your modern diesel off-road adventure machine to the ground - without really trying at all. A triumph of no effort...
This story was sparked (See what I did there? It’s why you pay me the big bucks...) by a couple of recent recalls:
The Mazda BT-50 and Ford Ranger utes - they’re built in the same factory in Thailand. Clones - or at least, dizygotic twins. That recall was widely reported. This report is about fire risk in modern off-roaders broadly - but here’s the catalyst.
IS YOUR UTE AFFECTED?
Alternatively, visit any authorised dealer (bring the VIN code - it's on the rego papers). They can look it up and tell you.
- Or ring Mazda on 1800 034 411 or send Mazda an enquiry >>
- Ford is on 13 36 73 or here at Facebook >> or send an e-mail to email@example.com
The back-story is that if you drive off-road, grass can build up around the diesel particle filter - the DPF - and if the conditions are just right - just wrong; depends how you look at it - your shiny new BT-50/Ranger can be gone in 60 seconds, or less. This process affects other vehicles as well.
"If the grass or vegetation comes into contact with the exhaust system components that operate at a high temperature, there is a risk that such debris may be ignited by the exhaust system. In the worst case scenario a fire may originate in the vehicle underbody area."
- official Ford/Mazda arse-covering recall jargon
"We did such a bad job designing this that if dry grass builds up around the exhaust the vehicle will potentially burn to the ground in seconds and the occupants (you) will probably dies in screaming, brutal terror. The ensuing fire could easily endanger other lives and destroy hundreds of hectares of native bush and/or agricultural land plus crops and wildlife. Sorry about that."
- what it really means
AFFECTED VEHICLES IN THE THOUSANDS
This recall affects about 52,000 Rangers and 17,000 BT-50s built between mid-2016 and now, basically. In a typical Ford botch job - and it must be said that they are specialists at throwing in, free, spontaneous combustion, seemingly with just about every model, the parts to remedy their typically crap engineering are unavailable.
So - instead of fixing the problem immediately the pyromaniacs at Ford will be sending affected owners a diagram, presumably drawn by the intern, in crayon, so you’ll be able to check whether your new $60,000 ute is about to do the whole Joan of Arc bit, unexpectedly, while you are busy beating the wilderness into submission like the Daniel Boone you’ve always dreamed of being.
There are cars in dealer stock now (Feb 2018), unsold, at both Ford and Mazda, subject to this very recall, and despite the risk, neither manufacturer has seen fit to call a halt to sales. That certainly tells you something.
The sheep - and by ‘sheep’ I mean the Australian motoring press - dutifully reported the recall. Unfortunately, because they are so inept, technically, and so brethtkingly uncreative, some would say dead from the neck up, unkindly, they failed to provide any context beyond ‘here’s the recall - here’s what Ford said - here’s what Mazda said’. Next...
The chemical mechanism of this potential conflagration is easy to understand. If you drive off road, dry grass can in some cases build up around hot exhaust components. If the exhaust heats it up sufficiently, the grass catches fire. The fire can spread quickly and consume the vehicle in seconds.
Fire is a runaway oxidation reaction - the flames that kill you are just the radiating plasma. To get things started you need fuel (dry grass - excellent choice) input energy (in the form of heat, thanks very much exhaust system) and oxygen (supplied in this case by rapid airflow from the moving vehicle). So it’s a rolling one-stop conflagration shop.
This fire business can of course be terribly serious at any time but especially off road - in remote conditions - in ‘Stralia. When a vehicle catches fire, the time between you knowing it’s ablaze, and the vehicle being totally consumed is just seconds.
Jason Morrison is the News Director of Seven News in Sydney. I’ve known Jason for several years. He’s not a bullshitter. Mr Morrison’s Ford Territory caught fire on Saturday the 1st of July this year at a set of traffic lights in Sydney, and he sent me the photo, captioned: It said: “10 seconds and it was gone.” 10 seconds.
Write down a list of achievable priorities in those 10 seconds, such as stop the car safely, get the kids out, etc. It’s gunna be a busy 10 seconds, I’d suggest.
This is guaranteed to get your pulse racing in the suburbs - even though you have cellphone coverage, and easy access to medical care and firefighters. But in the boonies, if you lose your vehicle in this way, you also lose all your shelter and all your water, all your communications, first aid kit... If it’s remote enough and hot enough, or cold enough, you are dead. That’s just from exposure. Even if you’re uninjured - dead. A lot of off-road adventurers never consider this.
How many off-roaders visiting truly remote places do you suppose even cross this bridge and prepare adequately? Not many. Here’s how they’d do it in the military, or the boy scouts: you’d have a ‘go bag’ that you could reach in seconds - water, shelter, first-aid, sat-phone, EPIRB. You’d grab that and hurl it as far from the vehicle as possible.
And I’d suggest you’d have a fire extinguisher. A really big one. And not packed right down the bottom of all the gear. Accessible. PS - vehicles don’t blow up like in Hollywood fighting the fire is probably reasonably safe in the context of being in a remote area where the alternative is death if you lose the lot.
It seems to me that most of these blue singlet wilderness warriors do not actually consider how utterly dependent on their vehicles they are - just to survive the next 12 hours in a truly remote, inhospitable place.
THE PHYSICS OF GRASS FIRE
Dry grass catches fire spontaneously from about 300 degrees C - it’s not a straightforward process or an absolute temperature thing. It depends on several factors - like the moisture content of the grass, the contact temperature, radiant heat load, and airflow - but the point is, every modern diesel exhaust system is more than capable of autoigniting any dry crass it can latch on to.
Ralph Gonzales, a mechanical engineer working for the San Dimas Technology and Development Center in California on an occupational health and safety project for the US Department of Agriculture found in 2008 that all but one component of the exhaust system of a modern diesel exceeded the autoignition temperature of what he described as “forest fuels”.
Download the report here >>
And here’s the catch - that component was the DPF. It was the only thing insufficiently hot to burn the grass. See, the DPF is a furnace, but it’s kinda insulated. Everything else - including the exhaust gas exiting the tailpipe - was hot enough to autoignite dry grass.
Just to put some numbers on this: PDFs can’t really do their regenerative voodoo below about 500 degrees C. Dry grass starts to char from about 190. It’s a pretty slow process, burning at 190 - typically requiring several minutes for a bit of a smoulder. But at 500 degrees, in high wind, fire is almost instantaneous.
These were the findings of another accredited combustion brainiac, William Pitts, who wrote the miracle cure for insomnia back in March 2007. It’s called ‘Ignition of Cellulosic Fuels by Heated and Radiative Surfaces”. Edge of the seat stuff. Un-put-downable.
Download the report here >>
Mr Pitts did that for the Building and Fire Research Laboratory inside the US Department of Commerce. The purpose was (quote) “to characterise the ignition behaviour of typical outdoor fuels heated by mufflers and catalytic converters”.
He tested four different types of grass, plus pine needles, a grass and pine needle cocktail, plus shredded paper, and did preliminary tests with leaves and also polyurethane foam. So I bet he’s a hoot at parties. And I wouldn’t cross him - not without the fire department on speed dial. Anyway...
TIPS FOR FIRE-FREE OUTBACK ADVENTURING
There’s a couple of things you should be aware of, and act on, if you’re going to take your shiny new off-roader adventuring this fine hot, Aussie summer.
Number one: Dry grass doesn’t look dangerous, but it is. In fact, one very dangerous thing you can do is pull off the highway onto the verge - in any car - if that verge is covered in dry grass. You won’t know, but if the DPF has just been doing its its particle immolating voodoo you could easily be parking your 600-degree exhaust on - literally - a tinderbox. That could end badly.
Then there’s driving down two wheel ruts separated by a grassy crown. This is an excellent way to wedge dry grass in underbody pinch points. If the manufacturer of the vehicle hasn’t done an especially ace job in R&D, grass can easily accumulate between (commonly) a heat shield and the hot exhaust itself. That’s really bad.
The exhaust might not be hot enough, and the airflow insufficiently fast, during slow track driving to set it all off, but if you get back on a decent road and the DPF says, ‘well golly-gee, Jim-Bob, better have a hoe-down and regenerate’ temperatures could skyrocket, and of course there’s the 100 kay-an-hour wind literally whipping up the flames. That could get disproportionately interesting in a hurry.
So although the recent recall references Ford and Mazda only - I’d be thinking twice about getting away from it all over a beautiful straw-coloured grassy field, swaying seductively in the breeze, mid-summer, in your awesome new diesel escape machine. Especially if there’s an alternative.
I’d also carry that fire extinguisher. A big one. And the go bag. And I’d make sure all the parties to our awesome off-road adventure knew exactly what to do if evac the vehicle like we mean it, in a fire - this would include pesky details like not running in a panic across a busy road and getting cleaned up in the traffic, and doing a head-count to make sure everyone is OK.
I know this sounds, like, very basic - even intelligence insulting - sitting here watching a YouTube video. Stressful situations do tend to imprison your capacity for rational thought, in solitary confinement. And, statistically, only 20 per cent of people can function in a crisis. It’s why the safety briefing on an aircraft is the way it is.
Anyway, I’d poke my damn head under the car from time to time safely - stopped, in Park, handbrake applied, minimum. I’d do this simply to confirm I wasn’t collecting grass for my own personal remake of the cowering inferno later on.
Of course it’s not as if older diesels without DPFs and even petrol vehicles are immune to this fire risk - I’d be checking them routinely as well, as part of a sane off-road risk-management exercise. And I wouldn’t be parking on any dry grass.
I would not hesitate to heap shit on Ford for always striving to deliver new and creative ways to burn you to the ground. Because they certainly deserve it, for being so profoundly crap at this, for so incredibly long.
Outdoor fun in ‘Straya. Yes! Outside the car there’s everything from saltwater crocodiles to death adders and king browns. The funnel web spider in you boots. Inside the car there’s negligent malice from Team Autoignition at Ford - arseholes. Just remember - pain is simply weakness leaving the body, and if it doesn’t kill you, it just makes you stronger. I hope this helps. Thanks for watching.
Maddens Lawyers to investigate class action lawsuit:
If you are the owner of a reasonably new Ford Ranger or Mazda BT-50, in ‘Straya, there’s a class action brewing, off the back of the recent fire risk fiasco. You might be entitled to compensation. Here’s what you need to know.
Maddens Lawyers this week announced its investigation into a class action against Ford and Mazda. This relates to Ford Rangers built after July 2016, and Mazda BT-50s built since June 2016.
Maddens Lawyers have a registration page >> for Ranger/BT-50 owner who might in time be eligible for compensation over this. Or you can call them on 1800 815 228.
STATE OF PLAY
The state of play: There are official safety recalls active on both vehicles. There’s a clear risk to life and property, and also livelihoods - in the case of agribusiness and forestry.
According to Maddens Lawyers:
“There have been numerous reported incidents of fires.” - Maddens Lawyers
A very concerning aspect of this safety recall is that brand new vehicles on dealership showroom floors right now are being sold knowingly with this serious safety defect.
A fix is not yet available and is not expected to be rolled out for several weeks. Neither Ford nor Mazda has withdrawn existing stock from sale, which is hardly admirable conduct in my view.
Maddens Lawyers Class Action Principal, Brendan Pendergast, said there’s no certainty the recall will satisfactorily resolve the immediate fire risk.
“There are a number of issues. Not only it is yet to be determined if the newly developed parts will work safely, but also the impact on resale value”
- Brendan Pendergast, Maddens Lawyers.
Therefore, it seems, the so-called science of truck now includes a not altogether free dose of spontaneous external combustion. Yesssss! A real engineering ‘own goal’.
Maddens Lawyers is not involved in this report. I have spoken to them, off the record, but this is not a sponsored segment. I just think as an owner who has been let down by this defect, you should do all you can to level up the playing field between you and powerful these carmakers who are playing fast and loose with your safety and your investment.
Maddens Lawyers says registering your interest with them is not a commitment to take legal action down the track. So it seems obligation free.
THE PROBLEM WITH RECALLS
Even more worryingly, for future Ranger and BT-50 purchasers in the used car domain, perhaps years from now, there’s the low completion rate of so many recalls. Recalls are entirely voluntary. There’s inadequate carmaker follow-up and woeful regulatory oversight. That’s a double-barrelled blast of bureaucratic bullshit into the consumer right there.
If you were to buy a used Ranger or BT-50 in, say, five years’ time - this recall might not yet have been done to it. Bad news for you if you then trick it up for that off-road round-Australia adventure you have always dreamed of. It could end badly.
So - good safety tip: Whenever you buy a used car - make the manufacturer aware you own it. You can usually do that online. You’ll need the VIN code and some other details. Then they can contact you about any future recalls.
Also, just after you buy a used car, take it (or just the rego papers) to any authorised dealer’s service department. They can look up the VIN code and let you know if there are any outstanding recalls or service campaigns on that car - and they do this work for free. They send the carmaker a bill - it’s not a charity.
The regulators are complete lazy arseholes on this - very keen, I note, to fine you for five kays over the limit, or anything else trivial. Quite disinclined to follow up the tens of thousands of ticking time bombs driving around on our roads today - meaning all the cars with serious safety defects in the form of recalls that have not yet been completed, and never will be.
Bureaucrats - champions at one thing: Sucking on your taxpayer teat and simultaneously bullshitting you with 1000 reasons why the status quo is not just adequate, but in fact beyond excellent.