I drive a 1984 Mercedes 300D. Guy hit me from behind about a month ago with a full size pickup truck going at least 30mph. All he did was break some plastic in my one tail light. No other damage whatsoever. It’s like a panzer.
I drive a 1984 Mercedes 300D. Guy hit me from behind about a month ago with a full size pickup truck going at least 30mph. All he did was break some plastic in my one tail light. No other damage whatsoever. It’s like a panzer.
I have a ‘85 MBZ 300D in great shape. Identical to the one in the picture. Still use it on long trips, get about 27 mpg.
First, some assumptions:
+ (KE absorbed by truck) + (KE absorbed by Mercedes)
You say the Mercedes didn't take hardly any damage. (Note: I'd have the foam foundation of the rear bumper checked out, it may have absorbed the energy without giving any outward tell-tale signs it's now comprimised.) So let's say it absorbed only 5% of the crash kinetic energy.
Let's say, for sake of argument, that a modern truck, sturdy but designed with safety in mind, absorbed 20% of the crash energy.
That leaves 75% of the kinetic energy to be absorbed into velocity changes. Let's solve for that, which is v2 in the above equation:
v2 = sqrt( ( 1.3333 * (m1*u1*u1 + m2*u2*u2) - m1*v1*v1 ) / m2 )
(Plug & Chug numbers....)
v2 = 19.666 mps, = 44 miles per hour
Let's say the time the crash takes to impart that energy is a third of a second
From a standing start, acceleration = velocity / time
acceleration = 19.666 mps / 0.33333 = 59 meters per second square
Thats 6 G of acceleration being put upon the passengers of the Mercedes. That ain't good. At 5 gs people lose consciousness.
Now, my exact numbers may be off by some, but the equations are valid, and the point remains: cars absorbing kinetic energy is GOOD. Cars taking damage is GOOD (if done outside of passenger zones), because that keeps the G-forces from reaching the passengers (BAD).
Please get the energy-absorbing elements of your Mercedes rear-bumper checked out!