Tom McCahill, considered by many to be the father of the magazine road test invented the 0-60 comparison metric back in the early 1950s when he was testing cars for Popular Science and Mechanix Illustrated. The National Highway System was being built at the time and the proposed speed limit was 60 MPH, so it made sense that a useful metric in comparing cars would be the time to get up to highway speed and safely merge. Like many grandfathered standards the 0-60 time might not be the most relevant today (a 0-75 MPH or 0-100 MPH time is likely more useful) but it’s what stuck. Electric cars, the most modern of the automotive world, are locked in an all-out 0-60 war. Which got me thinking: what’s the fastest 0-60 time a human could survive?
Acceleration is the rate of change of velocity of an object with respect to time. In the automotive world, we commonly measure acceleration in terms of ‘G-force,’ where ‘G’ refers to gravity. Essentially, we’re comparing the force of acceleration due to gravity to the force of acceleration due to your bitchin’ or not-so-bitchin’ ride.
On Earth, we experience the force of gravity in the direction of the center of the planet. At sea level, the force of gravity is measured as 1g. When you’re standing, 1g is the amount of force exerted up into your feet by the ground.
When we talk about acceleration in a car, we’re talking about g-forces acting on the car and its occupants in the horizontal axis. Basically, the g-force in a car is the force applied to your back by the seat when you hit the gas and are thrown backward into it.
Let’s say you’re driving some fairly standard, pretty boring family sedan with a 0-60 time of 12 seconds. You can figure out how many Gs you’re pulling by first converting your speed to feet per second (1 MPH = 1.46667 feet-per-second). Then, we can divide by 32.17405 ft/s², which is what 1g is in feet per second.
60 MPH * 1.46667 ft/s = 88 ft/s
(88 ft/s / 32.17405 ft/s²) / 12 seconds = 0.228 Gs
So, a 0-60 MPH time of 12 seconds will expose you to a little less than a quarter of normal Earth gravity. Now, lets work backward and see how fast a car would need to get to 60 MPH in order to have a normal Earth gravity of 1g.
(88 ft/s / 32.17405 ft/s²) / X seconds = 1g
Remember how to do algebra?
2.74 seconds = 1g
So, 1g is getting to 60 MPH in 2.74 seconds. That’s pretty quick, but also doable in some modern cars. A Tesla Model S can get from 0-60 in 2.39 seconds or 1.14g, that’s actually greater than Earth gravity. But, that’s still perfectly safe.
Top Fuel Dragster Acceleration Gif[/caption]
We need to go faster! Let’s consider a top-fuel dragster which can go 0-60 MPH in about 0.2 seconds.
(88 ft/s / 32.17405 ft/s²) / 0.2 seconds = 13.7 Gs
Now we’re talking. In the 0.2 seconds, it takes for a top-fuel dragster to get to 60 MPH you would feel it (you’d feel almost 14X heavier in fact) but it’s still not going to kill you.
The Largest G-Forces Felt by Humans
Automobiles aren’t the only places people experience big G forces. Astronauts routinely endured 3g during shuttle launches, 8g atop a Mercury-era Atlas booster rocket, 7.25g aboard a Gemini-era Titan rocket, and around 4g for the Saturn 5s. Mercury capsules hit 7.8g during re-entry, Apollo capsules topped 6g. Roller coasters can provide up to about 6g. And fighter pilots in compression suits can survive 8 or 9g for a few seconds.
The most extreme G-forces mankind has ever felt weren’t in space or on the way to it, though, they were right here on Earth. The most extreme G-forces a human has ever endured happened on a rocket-powered, track-mounted acceleration sled, and it was done by Air Force physician John Stapp to see just how many Gs the human body could really handle.
In the late-1940s, Stapp was sending himself down the rails on a rocket sled which was violently accelerated then stopped just as abruptly, he showed the body could withstand up to 35 Gs and survive.
Stapp is also known for Stapp’s Law, which states:
“The universal aptitude for ineptitude makes any human accomplishment an incredible miracle.”
In the 1950’s, Stapp built a rocket sled called the Sonic Wind, which accelerated him to 632 mph in less than 5 seconds to then stop him in just one second. This generated an insane 46.2 g (at 168 pounds he would have felt like he weighed over 7,700 pounds). Stapp didn’t have the benefit of being in a closed car either, he was exposed to 2 full tons of air pressure during the ride.
Stapp’s incredible rocket sled record was broken in the 1970s Major John Beeding, an Air Force volunteer, aboard the Daisy Decelerator. He endured a whopping 83g during the sled’s deceleration.
The Fastest 0-60 MPH Time a Human Could Survive
So, let’s say we go with Major John Beeding’s record of 83gs as a blueprint for our super-fast 0-60 car. Sure your dental filling might fall out and you might leave with some cracked ribs but at least you’ll survive right?
(88 ft/s / 32.17405 ft/s²) / X seconds = 83g
0.034 seconds = 83g
So, if you want to experience the fastest 0-60 MPH a human could theoretically survive you’d have to do it in an incredible 0.034 seconds. That’s fast, for perspective 0.101 seconds is the current fastest reaction time recorded for human beings. The average reaction time of human beings is around .215 seconds. So, fast and totally not dangerous at all!
Get on it Tesla!