I always thought that gasoline caused most vehicle fires, but I have seen a
lot of semi tractors that burned. The only difference is that diesel needs
a wick or it needs to be heated enough to vaporize. Gasoline evaporates
easily at air temps. Since diesel has more BTUs per gallon, it will burn
longer or hotter once lit.
Metal scraping on pavement provides enough heat and sparks to light even
diesel in some conditions. Even a 240D (or 190Dc auto) can create a pool
of fuel and a stream of sparks. The local independent shop has the remains
of an SD that caught fire while driving down the interstate. I would have
believed that to be impossible until I saw it. The fire does not appear to
have started at the alternator or battery. It appears to have burned
longer/hotter on the left side (where the fuel is) of the engine
compartment. It got hot enough that the valve cover melted. I can't find
an explanation of the cause of the fire. I can only surmise a combination
of oil leaks, fuel leaks and a seriously overheated/sparking electrical
component (CC fuse maybe)
One thing that I have noticed is that on the old cars with the tank under
the trunk (107-115 inclusive) if a fuel line is cut or broken, the fuel
stays in the tank. In the interest of "safety" after the Pinto debacle,
the feds made the tanks move to behind the passenger seat. On these later
cars, the fuel will run out to the ground if you cut or break a fuel line
in the engine compartment. If a fire did start, these tanks will feed the
fire. This is independent of manufacturer.
Loren
At 07:08 PM 1/24/2006, you wrote:
Surely a big part of why the Toyota fire happened is just that it was
a gas car? That's one big safety advantage of diesel that many people
don't think about---it's combustible, but not inflammable, much less
volatile. Not saying that MB's aren't safer than other cars, rather
that there's a big fire-safety bonus to driving an oilburner on top of
the inherent crash safety engineered into the car. (And not to
mention the fact that a 240D is incapable of acquiring enough kinetic
energy to damage itself or anything else in a collision!)
Alex Chamberlain
'87 300D Turbo
