Now that there are more EVs on the market, a lot more cars have frunks. That got us thinking—do frunks pose a safety risk that we haven’t seen before? In the event of a front-on crash, what happens? Does a frunk’s cargo effect crash safety?
Frunks are more common in the EV era, but they’re not a new invention. Historically, most cars had an engine under the hood, and that was it. Rear-engine cars with under-hood front storage have been around almost as long as modern cars have been on roads, but even when rear-engine models were at their peak number, they were the rare exceptions to the front-engine rule. Now that EVs have made the frunk virtually mainstream, it’s worth looking at it in more detail.
I decided to hit up a couple of industry agencies and a professional engineer for their opinions on the matter. I learned that, while frunks aren’t a major safety risk, you can still do some harm if you’re particularly reckless or stupid.
What’s the Difference?
The front of the vehicle is a critical piece of crash structure for protecting the occupants. The thing about frunks is that they’re a large volume inside the front of the vehicle that is effectively uncontrolled. In traditional front-engined vehicles, this isn’t the case. Even though these cars have a big heavy engine up front, the vehicle is engineered to deal with this in a crash. Often, engine mounts and surrounding structures are designed to allow the engine to break free and move in such a way that it doesn’t present a risk to the people inside the vehicle.
In a frunk, though, the automaker has no idea what you’ve put in there or how it’s going to behave in an accident. Adding to the risk is that the frunk is generally directly in front of the driver and passenger. Thus, you might think that in a front-end accident, anything in the frunk could have an effect on the crash safety of the vehicle.
It’s easy to imagine a head-on collision turning fiery if you stored a big can of gas in the frunk, for example. But what would happen if you put a big heavy metal anvil in your frunk? Or a toolbox, or lots of lengths of steel rebar? These were just a few scenarios I gamed out in my head. An anvil or rods of rebar would surely pose a serious penetration risk to the cabin, right? And yet nobody seems to be talking about this!
My first port of call was the Insurance Institute for Highway Safety (IIHS). This independent organization investigates crash safety with the aim of reducing deaths, injuries, and property damage from motor vehicle accidents. The agency was first founded by three major insurance associations. As you might imagine, reducing negative outcomes from car crashes would have serious benefits for insurers. So, if anyone was concerned about this, surely it would be the IIHS, right?
The response from the IIHS ultimately suggested that it doesn’t see frunk safety as a big deal. “Carrying cargo in the frunk doesn’t raise any specific safety concerns,” said Joe Young, director of media relations for IIHS. Young did note, however, that it’s still not wise to put just anything upfront. “That said, placing something that is explosive or flammable in that space could present unique risks, as it would in a trunk during a severe rear impact,” he continued. Young noted that at this time, the IIHS does not place any objects in a frunk during crash tests.
Next, I wrote to the NHTSA. At the time of writing, the agency was yet to provide a specific response on the matter. However, they later came through with an update.
Electric vehicles currently undergo the same Federal Motor Vehicle Safety Standard crash tests as internal combustion engine vehicles. No passenger vehicle test requires placing cargo in the front or rear trunks expressly to test how that cargo would affect frontal or rear crash test results. NHTSA’s frontal crash tests of EVs thus far have been conducted with empty frunks.
Thankfully, though, at The Autopian, we’re well connected. I was able to reach out to an engineer who has worked on crash safety for decades. They were able to explain a lot about frunks and crash safety, and give me an insight into general industry thinking around this matter.
The Engineer’s View
Engineers routinely use a method called Design Failure Mode and Effect Analysis. This helps classify risks in terms of their likelihood of occurrence and the consequences if they occur. Naturally, it makes sense that crash safety engineers focus on highly likely scenarios with highly dangerous outcomes first, before they look at edge cases. For example, it’s important to make sure that passengers can safely survive common front-end or side-overlap crashes. That’s relevant every time an owner gets in their vehicle to go for a drive. We have real-world data that tell us what kind of crashes are most common and most dangerous, and automakers look to sort those out first.
Crashes where cargo in the trunk played a role simply aren’t popping up in the datasets. That means our hypothetical frunk danger scenarios just aren’t as relevant, statistically speaking. Frunk utilization isn’t anywhere near 100%, for a start. In many cases, it’s pretty low. On some vehicles, some owners never even use their frunk, because it’s too small or inconvenient.
Even on vehicles with big frunks, like the F-150 Lightning, owners probably don’t use them every single time they drive. And, when they are using the trunk, it’s an even smaller percentage of the time that they’d even consider putting something potentially dangerous in there. And for a lot of frunks, their very design can inherently limit the potential danger. If you’ve got an EV with a tiny, cramped frunk, what are you going to put in there that’s so dangerous, anyway?
Fundamentally, in regular use, it seems that we aren’t seeing a lot of dangerous crashes where frunk cargo was involved. If we were, crash reports would have filtered through to agencies like the IIHS, and crash safety engineers would be working on mitigating these risks.
That’s not to say there’s zero risk in how you use a frunk. It’s entirely possible to put something dangerous in your frunk that could cause you great harm in the event of a crash.
For example, if you put a ton of jerry cans in your frunk, or a bunch of propane tanks, they’re probably going to cause an issue in the event of a bad accident. Of course, this is no different than if you had them in the trunk of your car, and your vehicle was hit from behind.
It’s also possible to interfere with the front crumple zones of your vehicle, but this is a very unlikely scenario. My contact explained that if you’re putting something in the frunk that is rigidly transferring loads into the vehicle structure, you’re going to have a problem. Otherwise, you’re probably going to be fine. For example, if you put a small toolbox in your frunk, that’s okay.
However, if you build a super-tough, super-rigid toolbox into your frunk that’s directly in contact with structural members, or bolted in, that could cause issues. It could add a lot of rigidity to the vehicle’s front structure, changing how it behaves in a crash. The front end of a vehicle is designed to dynamically crush to absorb energy in a crash. Often, at least over 2.5 feet (0.8 m) of dynamic crush space is desirable. If your toolbox or other cargo is rigidly interacting with the vehicle structure, it could prevent this happening. If that energy isn’t dissipated properly in a crash, outcomes for the vehicle occupants could be far worse.
Intrusion is also a risk, but perhaps an unlikely one. I wouldn’t go stacking lots of steel rebar in my frunk, for example. At least, not in a front-to-back orientation where it might skewer through the cabin in a crash. Any rigid item that can focus a great deal of load on a point could pierce through to the passenger cabin in a crash, and this would be highly dangerous to the occupants.
Hard, heavy objects can be dangerous cargo in general, but that’s not really specific to frunks. You wouldn’t want a small solid anvil bouncing around freely in your trunk, and it’s no different up front. Either way, it’s still preferable to having it in the passenger cabin, where it could become a missile that gives you a permanent brain injury. A larger, heavier anvil that fills the frunk space would likely be dangerous, given it could cause cabin intrusion in a crash. If you really had to move one, you’d be better off sticking it in a truck bed instead.
Ultimately, frunk safety isn’t that hard. Don’t chuck a bunch of flammable liquids or gas tanks in there. Don’t transport heavy, rigid building materials up there. And finally, don’t do anything that’s going to change the way the crash structure behaves. If you’re really having to shove in a big heavy toolbox to get it to fit, or you’re wedging in some steel beams right up against the frunk walls, you’re probably headed for trouble.
Don’t be silly out there, and you’ll be fine. Fill your frunk with prawns, not propane, and you’ll be safe out on the road. Stay milky out there, friends. Stay milky.
Image credits: Ford, BMW
Top graphic bomb image: Martin Bergsma/stock.adobe.com
If i were a standard maker, i would have them test the front-end collisions with a trunk full of a bag of tools and general luggage. If the luggage cannot fit, then just the tools.
“Don’t chuck a bunch of flammable liquids or gas tanks in there. Don’t transport heavy, rigid building materials up there. And finally, don’t do anything that’s going to change the way the crash structure behaves. “
So I should be fine transporting a bunch of fireworks and this mega pack of matches I have, right? RIGHT???
As long as you have loosely-packed boxes of nuts and bolts surrounding them on all sides for
shrapnel– err, padding.Things I would store in the frunk of the fictional EV I don’t own:
I look at the frunk picture of the Ford truck and marvel at the front visibility it would have had if they didn’t have to adhere to the Great Wall front-end aesthetic that’s required of modern pick-ups.
Don’t forget about packaging ‘peanuts’:
https://www.uline.ca/Product/Detail/S-1129/Peanuts-and-Dispensers/Uline-UPSable-Peanuts-Pink-Anti-Static-7-Cu-Ft-Bag
I did forget about those little rubber bouncy balls
Oh yeah… rubber bouncy balls are also a must have!
You can buy them in bulk here:
https://www.amazon.ca/Bouncy-Assorted-Designs-Stocking-Stuffer/dp/B081TJ5BCX
I think that storing food anywhere in a car directly in any compartment instead of an appropriate container poses a more immediate health risk than being dangerous in the case of a crash.
My non-work daily has a decal on the dash to the effect that carrying loose, unsecured, sharp objects in the trunk could puncture the fuel tank and risk fire in a high speed rear impact. Of course, it also had a quadruple 5 star NHTSA safety rating when new, so, I guess, I just can’t carry, like, a javelin back there. Point is, these concerns aren’t novel for electric cars and I hope it doesn’t become some sort of mainstream media hysteria that results in highly useful frunks being banned or something, like a lot of German automakers are probably hoping happens (and if the 25 year rule tells us anything, its that German automakers do often get what they want in this country)
I always make sure to put my Mk XIV torpedo in the frunk lengthways, that way it won’t detonate in a frontal crash.
And if you have someone going slow in the fast lane, you have a convenient way of taking care of them… as long as you didn’t put it in backward.
I am absolutely repulsed by the picture and idea of frunk shrimp. I can’t believe that’s an actual marketing image. Revolting
Retired coworker previously worked Boeing night shift. Someone told him and other new guy to have rocket transported to other Boeing facility. Being two new guys they did know that meant call the transport unit that specialized in such things. They loaded the rocket into back of a personal pickup truck. Security guard at second facility freaked out when they arrived with an experimental rocket in a personal truck with no safety precautions and no paperwork.
I know it has a drain, but I sure hope that Mach-E frunk is removable so it can be hosed out. Otherwise you’re never going to get all the shrimp juice or BBQ sauce out. Imagine the stench. Blech!
I keep my filled loose emergency fuel can in the frunk of the Porsche, which is probably considerably less safe than having a solid extra fuel tank in an BMW i3, but have never really given much thought to it, until now…
Not many hot or sparky parts in the front of the car, to ignite a ruptured can in a crash, so not going to move it.
it would be fun to see what engines from the same company can fit in the frunk of an EV
Not all collisions are frontal. Using this logic, nothing dangerous should go in a rear trunk, either, since it also serves as a crumple zone?
one more for the road, FRUNK THAT!!!
So society has come to this. What junk is in your frunk???? We live in sad, sad, times. I’ll get excited when they pull out a condo from the frunk. Till then, I’m just gonna pray for society
“Other EVs are so spacious that their frunks are used to celebrate the gruesome excesses of capitalism. I will never shake the vision of that woman’s gleaming yet irascible smile as she scoops shrimp out of the 4.8 cubic feet of front storage available on the 2025 Ford Mustang Mach-E. It haunts me.”
Dude! Have you NOT seen Jason and his wheelbarrow of shrimp? Compared to that gross exuberance this Mach-E frunk might as well be in a communist’s Tatra.
ummmm, will that crate hemi I just ordered off of Amazon fit??? Salesman said my frunk was huuuuuuge
Thought provoking. I now am as scared to put a 20 lb cylinder in the frunk as loose in the back hatch area. Or, as frequently seen on the back roads of Forgottonia, just bungie an old milk crate to the roof and carry the propane where it will remove itself from the scene in case of crash – just like the unbelted occupants!
I have a hard time to imagine what happened in the 22 instances of “noncollissions” in the multiple-vehicle crashes category. How can 2 things not collide in a crash?
When you successfully avoided colliding with another car by hitting a tree?
Or when you swerve to miss those two f’ing squirrels and they high-five when you crash into a tree.
But it’s labelled Initial Point of Contact, so even contact with a tree or wall would be a collision.
Road rage baseball bat to fenders and windows?
Panic swerve, car rolled? I wondered about this too.
I really had no idea anvils, big or small bounced. I would think a test having the recommended items in your car in the event of an emergency. A small can of gas? Boom. Flares? Fire. Water? Not in an EV. Full size spare? I’m kidding where can you get a full sized spare?
They do! Not well, but they bounce more than you would think. Metal has some elasticity, which is why it makes excellent springs.
Well I know my roadrunner cartoons and the anvils usually just burrow into the ground.
Acme brand anvils are made from dark matter.
Well to do the anvil test first we need a roadrunner………..
Well should we look for roadrunners on Carvana or Bring a Trailer?
When I drive on high-speed vintage rallies I take 5 or 10 gallons of extra gasoline with me. In the Corvair, the extra frunk weight caused front wheel rubbing so I moved the jerry cans to the back seat area. Problem solved and now I feel much safer.
At least Corvairs put the gas tank down low in the trunk area (I had to Google this). In my Super Beetle, the tank sits right above your legs. Before I finally got the factory style hard board trunk liner, careless loading of the frunk could disconnect the fuel gauge wiring. Fascinating to me that the Pinto got such a reputation, when I have to imagine old Beetles caught fire just as often. Especially with the fuel tank right next to all the dashboard wiring, fuses, and relays.
No frunk article is complete without the Mach-E shrimp.
A frunk full of shrimp, sans ice, would make for an awful avenue of revenge for a cheated on spouse/significant other/etc.
The autopian needs to one up them.
Considering the autopian could probably get their hands on a Ford Lightning, next year they should fill it’s frunk with mussels.
I have to say, if you’re going to make an aggressively different stainless steel EV truck and not make the frunk a coal-fired BBQ, what are you even doing?
An EV that burns coal? Maybe a super-sized George Foreman grill?
How else would Elon make his EV truck roll coal?
Technically, if your electricity comes from a coal fired power plant, your EV is coal powered. In that same vein, a few years ago I ended up behind a Tesla at a stop light with “coalpwrd” vanity plates. I have no idea if their local power was in fact coal, but it made me chuckle.
This site would give you some idea https://app.electricitymaps.com/map
1 up on the shrimp barrow