For whatever reason, the amount of time it takes for a car to go from stationary to a-mile-every-minute is a big deal. We obsessively keep tabs on the 0-60mph speeds of almost every car, whether or not that car is even designed for performance. Electric cars are currently engaged in an all-out 0-60 war. That got me thinking: what's the quickest possible 0-60 dash before the acceleration kills you?
AU Editor's Note: Yes, I know we use 0-100km/h in Australia and any reasonably half-smart country that uses the metric system. But 0-100km/h is 0-62mph, and that 2mph actually makes a whole buttload of difference to a bunch of cars' times, especially when their gearing is optimised just for that 0-60 sprint. So, just read through this post from our American cousins, and if you want to complain about acceleration times, I'll see you at the next traffic light Grand Prix. -- Cam
Acceleration, as we all know, is just the change of velocity with time. We commonly measure acceleration in terms of ‘G-force,’ where the ‘G’ refers to gravity, because we’re comparing the force of the acceleration due to gravity.
With this in mind, 1g is considered to be the equivalent of the force of normal Earth gravity. When you’re sitting on a chair, 1g is the amount of force exerted up into your ass by the chair, to prevent you from going into free-fall.
When we’re talking about acceleration in a car, we’re (ideally) talking about g-forces acting on people on a linear, horizontal axis. So let’s figure out how many g’s a given car exerts on a human when driving.
Let’s start with a relatively leisurely (by modern standards) 0-60 time, like 10 seconds. You can figure out how many Gs you’re pulling by converting the speed to feet per second, then dividing by 32.17405 ft/s², which is what 1g is in feet per second. Or, you can use one of the many online calculators, like I did.
So, 0-60 mph in 10 seconds will expose you to 0.27g. Barely over a quarter of normal Earth gravity. To equal 1g of acceleration, a car would need to get to 60 in 2.74 seconds, roughly. If we want to be really, really exact, it looks like 1g is getting to 60 MPH in 2.73511683 seconds.
So, we all know 1g is no problem. Tesla Model S that can get to 60 in 2.39 seconds is pulling 1.14g, which is greater than Earth gravity, just by a bit. Again, no safety issue there. If we jump up to the acceleration levels of a top fuel dragster, we start seeing some bigger numbers.
A top-fuel dragster can go from 0-100 MPH is about 0.86 second—rockets don’t even accelerate that quickly, even if they do end up going much, much faster. That kind of acceleration is worth about 5.3g. Plenty, and you’ll definitely feel that (it’ll feel like you’re 5x your weight) but that’s not going to kill you.
So how fast would a car have to go before it did kill you? Really, it’s sort of a continuum of issues that happen to your lovely, meaty body. You can experience blackouts or even death if you’re subjected to 4-6g for more than a few seconds, but in very short bursts, humans have been shown to withstand forces of up to 100g and survive.
Roller coasters can provide up to about 6g, but the duration is so short, it’s not a health risk. Fighter pilots in compression suits can survive 8 or 9g, but for the purposes of cars, wearing special compression suits is cheating.
The record for a human withstanding acceleration was 46.2g, which was experienced by an Air Force officer named John Stapp, who was strapped into a rocket sled. Perhaps he was trying to capture a road runner?
So, for our fastest possible yet survivable 0-60 car, I think we should shoot for something under the 46.2g, because I suspect that Officer Stapp’s long career in dealing with acceleration and deceleration-related research may have conditioned him to be better equipped than the average driver.
By the way, he’s also known for something called Stapp’s Law, which states: “The universal aptitude for ineptitude makes any human accomplishment an incredible miracle.”
Other tests by Stapp had him being accelerated to 35g, and even then he occasionally broke ribs, lost dental fillings, and other similar inconveniences that many premium car buyers would find unacceptable.
So, with that in mind, let’s set 30g as our limit for zero-injury acceleration. A car capable of that could get from 0-60 MPH in 0.091 seconds. If we’re willing to accept some cracked ribs and lost fillings, we can get that down to 0.078 seconds, and if we think we can do anything John Stapp could do, let’s say 45g, then we can be as quick as 0.061 seconds to 60 MPH.
So, there you go. We’re not even close to as quick as we can be without dying. I guess that’s good news, right?