Fuel Tank Puncture

[coolieman1220]

So my buddy just called me up telling me a story. He drives a 2006 Volkswagen Passat 3.6. He's in Texas right now and says he was driving on the highway at a high rate of speed (probably about 100) when a truck had some rocks fly out the top and he says it hit the ground and i guess bounced up and heard a big bang from under the car. He noticed his fuel gauge dropping. He pulls over and checks and see's gas leaking from the fuel tank under the car. Dealer claims $2100 to fix it not covered under warranty.

My questions:
1) Is this a plausible situation?
2) If it is plausible then isn't that VERY dangerous?

[NSXType-R]

Doesn't the fuel tank self seal to some extent?

[clutch-monkey]

sounds plausible? there were pics a while back of someone who ran over a hunk of metal, and it punched through the floor of the cabin and embeddd in the roof...

[Cyco]

Why would accident damage be warrantied?

[clutch-monkey]

obviously not having an armoured fuel tank lifted out of an ASLAV is a defect to be fixed under warranty chris

[Matra et Alpine]

Yes totally plausible and why forest stage rally cars put a racing fuel cell in the boot
Club rally cars at a minimum woudl have kevlar skids on the tank/pipes area.

Not as dangerous as the mobies make out. Lots of fuel in puddles doesnt' actually burn very well

Dangerous ? Yes you coudl say so. Now find me any activity in life which does not have the capacity to be "dabngerous"

Sadly ambulance/accident chasing lawyers make some think that manufacturers should make everything 100% safe ... oh and for $10K sticker price MAX. Yeah right

[coolieman1220]

Why would accident damage be warrantied?

obviously not having an armoured fuel tank lifted out of an ASLAV is a defect to be fixed under warranty chris

basically i thought that something like that could be defective. I havn't heard of it often. Guess I got my answer.

[Lagonda]

So my buddy just called me up telling me a story. He drives a 2006 Volkswagen Passat 3.6. He's in Texas right now and says he was driving on the highway at a high rate of speed (probably about 100) when a truck had some rocks fly out the top and he says it hit the ground and i guess bounced up and heard a big bang from under the car. He noticed his fuel gauge dropping. He pulls over and checks and see's gas leaking from the fuel tank under the car. Dealer claims $2100 to fix it not covered under warranty.

My questions:
1) Is this a plausible situation?
2) If it is plausible then isn't that VERY dangerous?

That's why we invented insurance...

[nota]

not covered under warranty.

.....

[pimento]

.....

Omnomnomnomnom....

[IBrake4Rainbows]

Why wouldn't that be covered by warranty. Normal wear & Tear

That VK held up remarkably well, actually.

[DanVB]

$2,100? WOW!
What would it have been for a more common vehicle like an F-150 or a Malibu? $400? $500?

[G35COUPE]

So my buddy just called me up telling me a story. He drives a 2006 Volkswagen Passat 3.6. He's in Texas right now and says he was driving on the highway at a high rate of speed (probably about 100) when a truck had some rocks fly out the top and he says it hit the ground and i guess bounced up and heard a big bang from under the car. He noticed his fuel gauge dropping. He pulls over and checks and see's gas leaking from the fuel tank under the car. Dealer claims $2100 to fix it not covered under warranty.

My questions:
1) Is this a plausible situation?
2) If it is plausible then isn't that VERY dangerous?

1. The incidence does not sound plausible. A rock that leaves a truck at high speeds will find your wind shield much faster than it will find your fuel tank. A heavy rock will not have the momentum to jump off the ground and damage a fuel tank. A small rock will have the momentum to jump off the ground, but it will less likely have enough energy to destroy a fuel tank. Perhaps, your friend went over other materials on the road, and probably thought it was a rock.

And the energy to cause such destruction is greatly reduced by the time the rock gets to the rear of the car where the fuel tank may be located, which makes the case very implausible. At best, the rock should have hit the exhaust pipes and mufflers of the car before it gets to the fuel tank, which would also make loud thuds. At worst, it may have severed a weak plastic fuel hose which caused the leak.

Fuel tanks are designed to take abuse because of the safety associated with their rupture. Even rally cars that hit their bottoms in rally races, don't have fuel tank ruptures.

Insurance company should address the repair cost and not the dealership/auto manufacturer. The rupture is not a result of manufacturers defect and so the dealership will not fix it.

I have experienced all I have said here and so I know.

[Matra et Alpine]

1. The incidence does not sound plausible. A rock that leaves a truck at high speeds will find your wind shield much faster than it will find your fuel tank.

No, a rock carries the same momentum whether it meets the tank or the screen.
Any transfer of energy from the rock to the road is minimal.

A heavy rock will not have the momentum to jump off the ground and damage a fuel tank.

yes it might.

A small rock will have the momentum to jump off the ground, but it will less likely have enough energy to destroy a fuel tank. Perhaps, your friend went over other materials on the road, and probably thought it was a rock.

hmm momentum NEVER causes something to "jump" ... it's an inanimate object operated on by Newtons Laws of motion.

And the energy to cause such destruction is greatly reduced by the time the rock gets to the rear of the car where the fuel tank may be located, which makes the case very implausible.

WHat assumption are you making on what is absorbing the rock's energy ?
Rattling between road and car flat surfaces is not going to drop the energy by a lot

At best, the rock should have hit the exhaust pipes and mufflers of the car before it gets to the fuel tank, which would also make loud thuds. At worst, it may have severed a weak plastic fuel hose which caused the leak.

Too many assumptions. Sometimes in the world shit-happens and it misses all those pipes and perpendicular surfaces. Hell I was unlucky and had rock hit bang on the oil filter on the Mini .. thus causing oil to spray out at great force.

Fuel tanks are designed to take abuse because of the safety associated with their rupture.

AVERAGE abuse, not pointy rocks bouncing along the road

Even rally cars that hit their bottoms in rally races, don't have fuel tank ruptures.

Exposed tanks on rally cars get skids fitted typical 18 gauge steel tanks just aren't strong enough to handle a forest rally stage or even a yump on tarmac !
SERIOUS rally cars run proper race fuel cells inside the crash structure of the vehicle.

Insurance company should address the repair cost and not the dealership/auto manufacturer. The rupture is not a result of manufacturers defect and so the dealership will not fix it.

So far the only point we agree on.

I have experienced all I have said here and so I know.

KNow what ? The rally comments are wrong, the inertia/momentum is too specific to be applicable and rocks don't aim to avoid tanks

SOrry it's a bit harsh, but this IS one of those tough-luck scenarios.

[G35COUPE]

No, a rock carries the same momentum whether it meets the tank or the screen.

I don't disagree. I didn't say otherwise.

Any transfer of energy from the rock to the road is minimal

.

I disagree. "Minimal" is relative to the initial energy the rock had when it left the truck, and it is relative to the surface area of the rock which made contact with the ground first, and the amount of time that contact was made.

yes it might.

The larger the mass of rock the more energy it will transfer to the ground on first contact. It all depends on the surface area of the rock that made contact with the ground, and the amount of elapsed time involved in making that contact.

hmm momentum NEVER causes something to "jump" ... it's an inanimate object operated on by Newtons Laws of motion

.

Not so. Momentum helps to build energy and that energy can easily become kinetic energy, which can be directional. Energy is a vector quantity. And by "jump" I meant vector.

WHat assumption are you making on what is absorbing the rock's energy ?
Rattling between road and car flat surfaces is not going to drop the energy by a lot

My comments were made with a lot of assumptions, which I should have stated upfront, had i known that the discussion would eventually turn technical. The amount of energy that will be transferred to the road is a function of the rock's momentum, its surface area, and the contact time it had with the road. Other factors may include the elasticity of the materials used in making the road and how energy absorbent these materials are when things are dropped on them.

Too many assumptions. Sometimes in the world shit-happens and it misses all those pipes and perpendicular surfaces. Hell I was unlucky and had rock hit bang on the oil filter on the Mini .. thus causing oil to spray out at great force.

After taking into account my assumptions, I failed to see how a rock from a truck could cause so much damage without other extenuating circumstances beyond what the reporter of the story had stated.

AVERAGE abuse, not pointy rocks bouncing along the road

I disagree. Fuel tanks are not designed for "Average" abuse. Their rupture is a matter of life and death in many cases. You may want to read this article about Ford Crown Victorias and their fire problems.

Crown Victoria police cars still draw worries about fires | Metro - cleveland.com - cleveland.com

Exposed tanks on rally cars get skids fitted typical 18 gauge steel tanks just aren't strong enough to handle a forest rally stage or even a yump on tarmac !
SERIOUS rally cars run proper race fuel cells inside the crash structure of the vehicle.

Are you suggesting that the life of a rally race driver is more important than the life of a commuter driver, so that the rally race cars have life-saving fuel tank mechanisms and the commuter cars don't? Again, i disagree. Both rally cars and commuter cars are fitted with the best fuel tank technologies there is.

KNow what ? The rally comments are wrong, the inertia/momentum is too specific to be applicable and rocks don't aim to avoid tanks

I know because I have had rocks fly off a truck and hit both my cars at different times. None went under my car to destroy a fuel tank located in the farthest proximities of a car. A rock is more likely to hit a windshield than it is to cause severe damage to a fuel tank.