Here’s The Engineering Behind Jeff Bezos’ $20K Slate EV

I just looked at the new Slate electric truck — funded, in part, by Amazon’s Jeff Bezos — and I had a chance to chat with the new company’s head of engineering, Eric Keipper. Here’s everything I learned about the engineering behind this truck.

At the Slate event yesterday I had the chance to slide underneath a few prototype trucks to look at some hardware, so we’re going to have to start with the hardware and then circle back to my chat with Mr. Keipper. Let’s start broad and go into detail thereafter.

The Slate truck is built on a bespoke chassis the company refers to as the “Slateboard.” I was told this is sort of a hybrid between a unibody and a body-on-frame vehicle (more on that in my interview below), which makes me think of the Jeep Cherokee XJ and its “uniframe” construction consisting of two U-shaped unibody “rails” to which the floorboards are all welded; it also reminds me of the Rivian R1T, which also has a body welded to a pseudo-frame. I don’t have any great underbody photos of the body-in-white, but Slate did show a side image of this in its introductory video:

The body is made of steel (overall vehicle curb weight is 3,602 pounds), with colors in the CAD below presumably denoting different materials/material grades:

It’s an interesting design; you can see that there’s really limited space to package the battery (which, per Wired, uses nickel-manganese-cobalt chemistry from Korean company SK-On), as the wheelbase is quite short and that solid rear axle (more on that soon) pretty much takes up the whole back section of the truck.

Check out how pronounced that battery pack area is on the side of the truck, at least on the beta prototypes:

Speaking of the back section of the truck, look at the CAD image above and you can imagine that trying to keep that section nice and rigid probably isn’t exactly trivial, as that bed — which has no permanent top to help resist forces being imparted on it — probably wants to bend and twist.

You can bet that the joint between the bed and cab is a highly-engineered part of the truck, just as it was on the second-gen Honda Ridgeline (which required quite an interesting adhesive/bolted joint in order to delete the original’s “sail panels”). For fun, here’s that second-gen Ridgeline; you can see some of the same general shapes in the bedside:

As for the roll bar that’s bolted on by the customer when they convert the Slate from a truck into an SUV, it’s a stamped steel, with fasteners on the B-pillar, bedside, and bed floor (note, there will be trim covering this on production models):

It’s worth pointing out that, per whisperings at the media event, installing the roll bar and rear seats also involves the user plugging in airbags, which seems like a bad idea, except apparently there are system-checks in place to make it foolproof. I’ll have to ask Slate a bit more about this.

Speaking of airbags, Slate showed some fun crash test simulation imagery, though this is the best shot I got:

And here’s a photo of some real-world testing:

Slate says the truck is “Designed to achieve the highest safety ratings” and comes standard with Active Emergency Braking, Forward Collision Warning, and up to eight airbags.

Oh, and before we move on from the body, here’s a photo of the tailgate structure behind the skin:

The suspension is a MacPherson strut up front and a five-link DeDion tube in the back.

Here’s a look at the front suspension hardware under the prototype trucks, starting with this strut nestled nicely inside a plastic wheel-liner:

This shot shows the sway bar and outer tie-rod-end going to the cast aluminum rack-and-pinion steering:

Speaking of, you can get a decent look at that rack here:

Disc brakes stop each front wheel; the lower control arm appears to be stamped steel, and it appears to mount to a stamped steel subframe on the inboard end and a cast iron knuckle outboard (note; the sway bar link appears to be disconnected from this vehicle):

Here’s a look at the front suspension from a different angle (looking forward from just under the passenger’s door). No, I’m not entirely sure what’s up with that stainless steel brake hose, but remember these are prototype vehicles:

And here are a few blurry shots showing the front suspension from behind the front axle pointing towards the front of the vehicle:

Let’s move on to the rear suspension, which is more interesting than a MacPherson strut that you’re all used to seeing on pretty much all economy cars — back here we have a DeDion tube axle!

A DeDion tube is a great rear suspension for the Slate, as it allows for the use of a rigid axle (which is cheap, easy, and strong) without having to bolt the differential to the actual axle (which would yield lots of extra unsprung mass).

Here you can see how the 150 kW (201 hp) electric drive unit/transmission/differential is mounted to the chassis just ahead of the DeDion Tube (the architecture package-protects for a front-motor should an AWD be offered later), which itself features a track bar going laterally, two trailing arms, and two upper control arms:

Here you get a great shot of those stamped steel trailing arms and of the disc brakes and coil springs:

Here are a few more angles:

That’s about all I could get hardware-wise from the press event. I do want to point a few other fun things out; see the opening for the rear window? Well, that glass can pop up!

And it’s the very same glass that gets re-installed onto either fiberglass SUV “topper”:

I’d also like to point out that it appears that Slate has been using modified Mahindra Roxors as test-vehicles:

Anyway, let’s get to my interview with Head of Engineering Eric Keipper, who used to work at Fiat Chrysler back when I was there. This will be a bit of a “live blog-style” interview for time-reasons.

Quick Interview With The Head Of Engineering

I chatted with Slate’s Head of Engineering Eric Keipper, “Employee No. 3,” to learn how the company got started, and what the directive was when things started in late 2022.

Amazon Influence, And The Goal Of Building An Affordable Vehicle

“We want to build an affordable vehicle,” Keipper told me about what the initial brief was when he hired on 2.5 years ago.

When I asked about functional objectives,  he said those were up to the team to develop. “So right out of the box we had literally a whiteboard and nothing,” Keipper told me. “We started with a a narrative that kind of outlined the vision of the vehicle. Through that narrative and that vision, we started to develop the bill of materials, costs, the architecture, the content that we wanted in it, and then started to figure out like what kind of suspension do we want…what kind of horsepower do we think this thing’s got to have, where’s the battery gonna go?”

“We really started to piece together what the vehicle would then become and did really a multitude of studies to start to narrow the scope.”

I asked where that narrative came from, and Slate’s comm’s representative chimed in: “People at Re:Build Manufacturing offered us some seed money to get started.”

“Our founders put us in place with a little bit of seed money and the vision of the vehicle, so [the narrative] came from our founders, and that, so we use the the Amazon Working Backwards principles,” Keipper continued. This is interesting because I knew Slate’s main investors were included Bezos Expeditions and General Catalyst, but I wasn’t sure just how “Amazon” the organization actually is. Apparently Slate is using some Amazon processes, including “Working Backwards,” which Amazon describes thusly:

Most of Amazon’s major products and initiatives since 2004 have one very Amazonian thing in common—they were created through a process called Working Backwards. It is so central to the company’s success that we used it as the title for our book. Working Backwards is a systematic way to vet ideas and create new products. Its key tenet is to start by defining the customer experience, then iteratively work backwards from that point until the team achieves clarity of thought around what to build. Its principal tool is a second form of written narrative called the PR/FAQ, short for press release/frequently asked questions.

We both witnessed its birth. [Former Amazon employee] Colin [Bryar] was in his tenure as Jeff’s shadow when the Working Backwards process was launched and he participated in every Working Backwards review presented to Jeff in the twelve months thereafter. And Bill’s experience was forged by applying and refining the Working Backwards concept in the early stages of the process that led to the development of every digital media product.

“With this PRFAQ you actually take the product vision and put it in the marketplace out in time and then work backwards to basically where you are today and figure out how to work up that ladder…we had nothing, so having that vision in place…of the product and what it would look like at launch…it gives us a little bit of a feel for the type of brand we wanted to become, the type of product we wanted to have.”

“Yeah, yeah, so the vision itself was actually pretty narrow. It was a back to basics, only the essentials, truck, and the, the narrative did outline like low-cost solutions for suspensions and, you know, minimal sized battery that gets 150 miles of range, and to the point that…the things that are in the truck are only there as required to propel the vehicle and and offer it as transportation, but then, you know, we will offer an accessories portfolio around the vehicle such the customers can add those over time.”

“The vision even included composite exteriors so that we don’t have to spin up a paint job…that was right there up front.”

As for the 150-mile range, that wasn’t exactly specified in the beginning. “We ended up putting that range figure together, but the vision of a minimal sized battery that allows us to optimize for the customer’s commuting needs [was there at the beginning].”

Slate Looked At Suspensions In Cars From The 1960s and 70s, Considered an eAxle

“I think in the original it has slightly different suspension characteristics to it, but we over studies put a McPherson’s struck in place and up front and then we put a DeDion rear axle in the rear that ended up being the best solutions for the truck for us.”

“So, essentially looking at what a low-cost solution would be back to…some of the ideas in the original PRFAQ were: Take us back to basics, only the essentials from vehicles like those in the, say the ’60s and 70s, so if you can imagine any of the like beam axles or others… it’s taking us back to a time where there was infotainment where there was no, you know, crazy gadgets and advanced driving, etc.”

“We did actually search the market for a beam axle that is, an E-beam, such that, you know, it would allow us to have the motor on a beam axle. In our class of vehicle, it just wasn’t available at the time. So, the next evolution that we went through was looking at, you know, independent rear suspension versus, you know, something like like the Dion, axle where we would be able to source a motor and attach it…Having the DeDion axle just made the most sense from a capabilities perspective, but then also, you know, having that low cost solution that will allow our ride handling requirements to be there as well as the towing requirements, etc. So, so that’s really we we did a full deep dive and full decision matrix work as you would expect out of engineers that are doing architectural development.”

The Unibody(ish) ‘Slate Board’

“We named it the Slate Board because, when you look at a body in white, it’s, we started with a frame, architecture, and because it was gonna be a truck, we said it’s gotta have a frame, but then we started looking at efficient design and it really morphs itself into a proper body in white that wraps itself around the battery such that you have the battery below the floor and, and so that that frame ended up morphing itself into a unibody, but it’s it’s closer to a unibody, but we know that there’s nothing in the market that a single body allows for both the truck and the SUV without a single component being changed, so we have the ability to take the backlash and the partition out of the truck. That back gets reuse, bring the SUV components to the truck, and you can upfit to a 5 passenger two door SUV from the same exact body-in-white that you had at the truck that you purchased from the assembly plant.”

“Being able to then also have multiple battery packs that could end up underneath it where we’ve got the extended range and the standard range battery pack, so between the truck, the SUV, and different battery packs, all with the same Slate Board, that really is, you know, one of the unique things that we’re excited for customers to, to take and make their own.”

“If you were to look at it with even the trained eye, you’re gonna say it’s a unibody…as the  rails in the front head towards the front of dash then they dive around the vehicle to be essentially the sill on the outside of the on the outside of the battery…we studied obviously where to put the rails up front for to achieve our targeted US NCAP 5 star, as well as our targeted IIHS top safety pick…that really, that really guided us with where to put the rails and then, from a side impact perspective, it tells us where to, where to put the rails on the outboard side of the battery and what the what the thickness has to be, what the material has to be, and we took the right material in the right place approach, and so we, we’ve done multiple rounds of optimization, making sure that we’re optimizing the body structure to meet, you know, the body bending and torsion requirements, but also protecting the occupants, protecting the battery and making sure that we meet, you know, the right handling targets, the durability targets, the, and of course the safety targets.”

The Slate Was Only Ever An EV

When I asked if there was ever a Slate Concept that incorporated any other powertrain,” Keipper replied: “Literally the first drawing that I put on the the whiteboard was how we were going to configure the battery. So this has always been a battery electric. “That…. in and of itself was not a directive, but it’s something that, you know, if you’re going to bring a new car to market today,…, it’s gonna be electric. They’re more efficient, there’s more torque, the performance is better, it’s just, it’s the right solution…charging is now, you know, infinitely easy. You can charge overnight, even on a 110 outlet.”

“To meet your commuting needs, chargers are very available, you know, in and around town as well as the ability to put one at your house… I think the learning curve that people have had to go up regarding charging is, is at that inflection point, and I think folks are starting to get an understanding of it, and we don’t see that as a detriment anymore.”

I asked about range extenders, and Keipper told me: “Yeah, it’s, it’s not a consideration for us at this time and so we’re not studying it.”

Reductive Design: Making Many Parts One Part

I asked Keipper about ways the company saved money beyond the obvious ones like the lack of paint. “We literally questioned everything. And the things that did make it into the vehicle, we think need to be there for  good means of transportation, a good customer experience, and a safe, reliable vehicle…So things like remote keyless entry…cruise control, those are there because we really think they’re key attributes that the customers really want.”

“We spent an enormous amount of time talking about reductive design and basically how can we take, you know, five parts and make it to two or how can we take three parts and make it into one. So our entire dashboard, you know, the first concept that we had, I think it had like 40 components or something, and we, we literally cut it in half.”

“Our interior team and our interior design team, you know, worked hand in hand and figured out how do we through reductive design, minimize the overall cost and complexity such that we can put it together easily, but it still meets the customer’s needs. It’s gorgeous, but really focused on minimizing the number of parts. We did the same with the door panels. We’re doing the same with the body in white. We did the same with the front rails. We’ve done that continuously throughout. So the idea of reductive design is something that the culture in the company has really grabbed hold of and is allowing us to be successful.”

What’s The Next Slate Going To Look Like?

 

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“One of the, great question, one of the things that we do think that is different about Slate and the reason that we’re gonna be successful is our, our very specific focus on getting this one thing right. And so the entire organization, the entire company is focused on getting the truck and the accessory of the SUV in a rear wheel drive, you know, standard and extended range, Situation in in those configurations to launch, right? So we are, we are uniquely focused on getting that, not to say that we haven’t had some product planning meetings of, OK, what is next and working on how we, how we steer the company at that point in time when we’re ready to do so, but the, the company really right now is focused 100% on, on making sure that we get to launch with the truck and the SUV.”

It’s A Fascinating Machine

In short, Keipper said the directive from day one was to make a “reliable, durable, low-cost transportation [for] the masses,” and I think Slate has done it. It’s clear based on my quick look at the truck’s engineering that it will be, without question, one of the least mechanically complex high-volume vehicle offered in the US in a century. And as a diehard wrencher who enjoys likes maintaining suspensions and driveline bits but hates having to fix powertrains, the whole concept is music to my ears.