2023 Cadillac Lyriq Executive Chief Engineer: New EV Her ‘North Star’
Jamie Brewer, executive chief engineer for the 2023 Cadillac Lyriq, discusses mass targets, the finesse of regenerative braking – and the frunk phenomenon.
At the Cadillac Lyriq’s media drive program in Utah, SAE Media spoke one-on-one with Jamie Brewer, Lyriq executive chief engineer, about developing the first-ever Cadillac EV, its purpose-designed Ultium vehicle architecture and the uniquely styled SUV-wagon’s positioning in the market.
The Lyriq is just the second production vehicle (the first being GMC’s Hummer EV) to use the dedicated Ultium platform. I’m curious about the overall strategy for materials, because the Lyriq has a fairly conventional steel body. Did you consider aluminum bodywork or closure panels?
Yeah, we did look in aluminum — we looked at it a lot. We have a lot of mixed metals, but it [the bodyshell] is steel. But I would say a lot of different high-strength steels that we put together in a way that optimized the mass with the cost of the vehicle. We want this to be an aspirational-but-attainable vehicle. And as you start just putting aluminum in there, you really take the cost of the vehicle to a point where maybe it's not as attainable as we want. So, we absolutely looked at every possible area.
There is some aluminum in the body-chassis structure at the skateboard and small amounts in areas that our CAE analysis indicated would be valuable. We probably went through hundreds of optimization cycles on that body structure. And once we got the structure to the point where it met all requirements, then we put it through what’s called MCO, our Mass Component Optimization study; it's more rounds of CAE iterations to then say, ‘Okay, where can we do lightweighting, where can we take section out, where can we change material? And it iterates on all of the different opportunities from a mass-optimization perspective until we find that sort of perfect balance between mass, performance and costs.
Because the Lyriq is based on GM’s first wide-ranging EV architecture, how did you decide on a mass target — or did you decide it on mass target?
Yes, we did have a mass target. Before I answer that question, I’ve got to go back to the intent and purpose of the vehicle — the sort of the “North Star” for the team working in the vehicle. And that North Star was for it to be the best Cadillac SUV we've ever made. That was the priority.
So, did we have a mass target? Yes. Did we run into some issues during development where decisions would've had to have been made on the content or the design or the styling to enable the mass target that was originally styled?
‘Best Cadillac SUV ever.’ So, we did modify our mass targets to make sure that the vehicle that we were delivering was the Cadillac that we wanted to deliver. We're 5,600 pounds [2540 kg]. It is a heavy vehicle. It's not the heaviest out there. We've taken advantage of that mass by really making sure that our center of gravity is extremely low — and we distributed it very well. It's a heavy vehicle, but it doesn't feel heavy when you're handling it. From a real-world [driving] range perspective, it doesn't actually influence as much as from a test-weight-class perspective that you see with EPA.
You mention “North Star,” a name with a lot of history for Cadillac. Is that term still used internally?
No, it's me personally. It's just me — as executive chief engineer, your job is to balance the different needs and requirements. It's particularly difficult [balancing competing development interests]. I would sort of take myself back to what is my North Star. I took on this job because I wanted to create the best Cadillac SUV that's ever been made. There are times you have to remind yourself of that when you're having some of these really difficult tradeoff-type conversations!
You’ve already heard some criticism: the Lyriq has no frunk. I pulled off the underhood beauty cover and could see maybe not a ton of room for a frunk. Is that something that when this Ultium architecture was first being conceived, maybe nobody ought a frunk was going to become a big deal?
The number of meetings I had on this... First of all, this vehicle has a 19.2-kilowatt onboard charger. That had to go somewhere. Once we put in the onboard charger, there absolutely was still room for a frunk. But it would've been — you could have put a laptop or something in it. We're not talking about huge storage space.
So then that debate became, okay, I can give you a small frunk and a medium-size rear cargo area. Or we can take the space that's left under the hood, we can take a bunch of those electrical modules that we bolt to the side wall of the rear cargo area — every vehicle does it, right? — take a bunch of those and put them under the hood, too, and then shrink-wrap the trim. So, your trim comes in a couple inches [closer to] the sheetmetal. And give you the largest-possible [rear] cargo area.
It's either a small frunk and a medium size-cargo area, or no frunk and a large cargo area. Then, again, go back to your North Star. What's your north star? The best midsize luxury SUV on the market today. I would challenge that a real customer, once they get over the hype of a frunk, would prefer to have the biggest rear cargo area possible. I knew I was going to get hit in the media. But that wasn't my priority. My priority was the customer.
Where do you see the Lyriq in terms of segmentation? What are you calling it? I see the profile and see a little more wagon, maybe, than some SUVs.
My goal was for this to be the best luxury midsize SUV in the industry – irrespective of drive type or powertrain. From a segment perspective, we're really going after the heart of the midsize, luxury SUV segment. Yeah, I can see [wagon] too. Especially with that really low roof angle. But when you look at the chair height and the command view of the road, that really is what puts it in that SUV category.
Are you worried about a wagon perception? Wagons have had this oddball kind of neither-nor place in the U.S. market.
From our confirmation clinic, where we show sort of the final-design interior and exterior of the vehicle, this vehicle scored higher than any other vehicle in General Motors history. I think the public is ready for this vehicle. They seemed extremely enthralled by it and interested in it. So, no, I think it's going to hit right at the heart of the segment.
The Lyriq has a unique feature for regenerative braking – a steering-wheel paddle that delivers a progressive intensity of regeneration. What’s your feeling about regenerative braking – and is it a big part of the EV “experience?”
Some people hate regen. Some people love it. I put it in high [mode]. It's fun for me now. When I come up to stop, I like playing with that feathering. I like finding that sweet spot. I mean, we don't have manual [transmissions] anymore, right? It's kind of like that fun you have when you're feathering the clutch and you're finding that sweet spot.
Talk a little about where you came from before this. What were you working on before the Lyriq?
I've been at GM now for 23 years and I got my mechanical engineering degree from the University of Michigan. I do also have an MBA. But I've been sort of all around the company, mostly in various engineering roles. I started off doing vehicle performance at our proving grounds, noise-and-vibration work. So I'm very passionate about sound, about a quiet experience, about taking advantage of the customer sense of sound and sort of creating that emotional connection with the vehicle. But I've spent a lot of time in interiors, a lot of time in body exterior. And I've spent some time in chassis. I've been in the quality department for a while. And I've also done some roles that have been more engineering and business. Kind of everywhere, really.