Cannon shells were lot more effective, but modern civilian airliners have been lost to combustion in half-empty gas tanks, which is why they are now pressurised with 99% nitrogen, not air. An incendiary bullet is a much more reliable fire starter than a fast moving lump of lead, but anything that can strike a spark can do the job.
I put that forward as a possible explanation for your assertion that diesel and petrol cars were more likely to catch fire than electric ones. When we have a large number of 15-year-old electric cars on the market, some being maintained by DIY, we shall have a more balanced picture of their relative electrical safety.
Electrical fires in cars take a long time to work their way around to the fuel tank. Fuel tanks rarely ignite themselves without external cause whereas lithium traction batteries do.
You haven't provided any.
Your initial assertion that electric cars are less likely to catch fire then diesel or petrol ones. You have yet to back it up with any facts to show that a difference exists and is cause by the fuel and not by other factors.
...but generally isn't. (It has a very narrow flammability range.)
You appear ot have misunderstood where the risk comes from. Wirewound pots can make bad contact and generate small arcs which have quite enough energy to ignite petrol vapour within the range of flammability. The high concentration of the vapour is what stops it igniting. In-tank fuel pumps with commutators are safe for the same reason.
Ford came up with an idea that did away wth the carburettor: their system drew concentrated vapour directly from the fuel tank and diluted it with air to give the correct concentration for the engine. They never put it into production and I imagine the need for a completely reliable and foolproof flashback arrestor was one of the major objections to it.
The claim has been made here before, and backed up by car insurance data. A quick google search brought this up.
Look up "intrinsically safe" electronics. It takes about a microsecond (and an appreciable amount of energy) to get a electric discharge through gas through the "glow to arc" transition. Unless you tied a substantial capacitor directly to the wiper there wouldn't be enough energy available to get a big enough bubble of the vapour/air mixture hot enough to start a fire.
There is also the point that it takes a hundred volts or so (the Paschen curve minimum) to start any kind of discharge through gas at any spacing.
Not always true.
And other reasons which you don't seem to be aware of.
Getting the evaporation rate in the fuel tank high enough to sustain prolonged acceleration might also have been a problem. A resistive heater to boil off extra vapour when you needed it would have been a solution, but not an attractive one.
Betteridge's Law of Headlines: "Any headline that ends in a question mark can be answered by the word no".
It claims that fires occur in 25 per 100.000 electric vehicles. The link for that claim does not show that information. It leads to an idiot's guide to electric vehicles which answers such questions as "What is an electric vehicle"?"
It does not provide any links to support its other claims for "gasoline-powered vehicles" and fails to distinguish between petrol and diesel, sometimes lumping the terms together and sometimes referring only to petrol [gasoline].
There are no proper comparisons - only vague assertions with insufficient relevant evidence.
Petrol guages are electrical but, until recently, didn't use any electronics.
How strange, stage pyrotechnics can be set off by a few hundred milliamps from a 3v source.
That wasn't the point.
Not strange at all. The amount of energy you can dump in a low value resistor is quite enough to get it hot enough to ignite all kinds of pyrotechnics.
You wanted to get the potentiometer inside a petrol tank hot enough to ignite a fuel-air mixture, which is a very different kind of task.
You thought that you could get it to create an arc. I once had to work out how to start a xenon arc lamp, and I do seem to know more about arc discharges than you do.
You should do a bit of reading.
Hydrocarbons take more - about 0.26 milliJoules. Intrinsically safe electronics can't deliver that much energy fast enough ignite even hydrogen-air mixtures. There are schemes that certify such electronics thoroughly enough to keep insurance companies happy. I worked for Kent Instruments for a couple of years (1973-76) and they did sell intrinsically safe measuring gear. I never worked on any of it, but got told about it anyway.
So what? That doesn't discredit the information presented.
<snip>It actually leads to a catchall web-site
I merely included the link to provide an alternative to the rather more professional work that the Guardian journalist did, knowing that clowns like Cursitor Doom really dislike objective journalism that doesn't pander to their particular delusions.
The point about car fires was thrashed out here quite a while ago. If you want more links, dig out the thread for yourself. If I dug them out for you, you'd find even more spurious reasons for not taking them seriously.
Here's a little transformer that I designed, and its pick-and-place tool.
John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
But you didn't design it, you just commissioned it.
Whoever did design it would have had a copy of Ralph Morrison's "Grounding and Shielding Techniques" - perhaps the 1967 first edition which did concentrate on 50/60Hz magnetics and talked about techniques like double shielding which did reduce capacitatively coupled currents to quite low levels.
Fronting up to a transformer shop and telling them what you want isn't design. Wprking out what a customer needs from what they tell you of what they want is usually the tricky part of the design process.
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