When designing a new car, the key consideration around which all other decisions must be based is where to put the engine. What happens when that engine disappears, and designers can start with a blank slate?
During our introduction to the I-Pace, Jaguar’s all-electric SUV, we got to hear from designer Wayne Burgess on the challenges and opportunities presented when designing an electric car from the ground up. As Director of Jaguar’s Production Studio, Burgess is aware of why every surface, line and angle is where it is, and he gave us a walkaround of the car while explaining the factors that drove a variety of design decisions.
(The following has been edited for length and clarity.)
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Wayne Burgess: I count myself very lucky to be working in the car design industry at this point in history, because it’s a time of a real pendulum shift in the acceptance and volume of electric vehicles we’re going to see in the marketplace. And when we on the design team heard that we were going to be working on I-Pace, we were really excited to maximize every opportunity that an electrical architecture gives us.
Because we could take the I.C. [internal combustion] engine and the gearbox out of the car, we said “For the cabin, why don’t we push the windscreen forward, why don’t we give this car a real cab-forward dynamic.”
Looking at the profile of the I-Pace, it has much more in common with our C-X75 concept midengine showcar from a few years ago than it does a conventional two-box SUV.
The footprint of I-Pace is about the size of a Porsche Macan, but the cabin, because it’s over two-thirds of the length of the car, is actually about the same as the long wheelbase XJ. And that’s one of the wonders straightaway that you get from electrical architecture: The size of the cabin versus the footprint of the car is much more optimal. So we have that very different, very dynamic profile to the car.
Then we thought “Well, this car has to be very modern from a design point of view, but also has to be very efficient aerodynamically.” And that was something that we really enjoyed developing as well, because we had to come up with new solutions to make the car more slippery than anything we’d done before.
If we start at the front of the vehicle, we have a fairly recognizable Jaguar grill. We decided to do this for a very important reason: Jaguar’s still a challenger brand, we’re still growing our brand and trying to raise the recognition factor for Jaguars when you see them on the road. So we thought it was quite important that it had a Jaguar face that you’d recognize.
Because it’s an electric vehicle, it doesn’t need to draw in quite so much air as an I.C. engine vehicle. But when we started building prototypes and testing these cars, we found it does actually need to take some air in there to cool both the motors and the batteries. So whereas the grill was originally a solid surface, we’ve opened it up to take some air in.
But the big design feature is the fact that the grill surface rolls into the air duct in the hood, and the best way to view it is when you’re getting into the car–if you look [down the nose of the car] you can see daylight through that extraction vent.
That’s something that you can only really do with a car that doesn’t have an I.C. engine in the front. We were able to drop that duct into the space where normally you’d have the front of the engine. The air coming into the duct basically accelerates over the windscreen, then stays attached and passes under the flight and rear spoiler. It’s a drag reduction device.
The headlamps have the familiar Jaguar J-blades, there’s a quad signature in here, and that’s just to remind us that premium British vehicles like the first generation XJ and every XJ since always have this quad lamp graphic so we thought even in a car with all of this technology and LED lamps etc. It was nice to have that quad lamp signature in there.
Moving down the bumper, air curtains–these intakes channel air onto the outside face of the tire and keep it attached down the side of the vehicle. Again, it’s an aerodynamic management device.
As you come around to the side of the car, 22 inch wheels, obviously designers like to have a great wheel-to-body relationship,if we can have a big diameter wheel, that’s always a win for us.
People have been very impressed with the fact that this car looks very much like the I pace concept that we launched in LA are year ago last November. And I’ve said, well what’s actually the difference, the differences are tiny. From an exterior point of view, the wheels are the same design, but they are one inch smaller, so the concept car we went even bigger, we had a 23-inch wheel just to make a bigger statement, and the wheel arches were flared by 10mm more per side just to give the car a little bit more stance.
The production car is actually slightly narrower because it reduces the frontal area, and it improves the drag, and therefore improves the range. So we did that for very practical reasons. The drag factor is .29.
Moving down the side of the car, you’ll notice that unlike most Jaguars, I-Pace is very sheer-sided. The body side is flush with the wheels, again that is about keeping the air attached. And this led us to design the car differently. If you look at a car like an F type, for the E type that inspired it, historically Jaguars have had lovely tapered tails. Lots of plan shape, it really sweeps off behind the rear wheel arch. The problem with that is it’s not good from a drag point of view.
So on an F-type, the air tends to detach around about the middle of the rear wheel arch because of that beautiful tapered tail, the E-type even more so, so we had to really think about the car differently in terms of giving it sheer sides and a fairly square plan shape. But to give it that voluptuous, sexy feel that Jaguars have to have, what we did is we overcompensated in side view so you got these really voluptuous front and rear fenders.
There’s a beautiful curve over that front wheel arch, and then that drops through the waist, and then a lovely long, muscular rear fender. Again, feeling a little bit like the C-X75, it’s got that cab-forward feel to it, but we really amplified the side elevation of the car because we couldn’t do the usual hips-and-waist Coke bottle treatment that we like to do on Jaguars.
Also, because the car is quite deep, because it’s an SUV by classification, we introduced this graphic device down here:
This is a gloss black insert that has the Jaguar script on it, to give the car the feeling of some planned movement around there. The fact that it rises, and then drops down again gives the sense that there is some Coke-bottle by using a graphic to convey that feeling.
Where we could get sculpture into the car, are these little aerodynamic skaggs behind the front wheel and ahead of the rear wheel. And again, they’re about keeping the air attached to the outside faces of the wheels and reducing drag.
You’ll notice the rear of the car has, for a Jaguar, quite a square plan form. Again that is good for aerodynamics. Keeping the corners out and square, and having a very clean separation point, that’s the lowest drag solution. It’s more like a cam tail. So you’ll see that we’ve got a hard crease in the rear fender, and in the tail lamp graphic as well, and that’s about giving the car a very short, clean separation point right at the back of the car. And if you can keep the air attached for as long as possible, and separate it cleanly, it results in minimum turbulence, minimum aerodynamic drag.
One of the things I love about the rear screen of this car, apart from the fact that it’s very three-dimensional and looks like a visor from a racing helmet, it’s that it’s so aerodynamically optimized that we don’t need a rear wiper.
If the car’s moving forwards, the rear screen stays clean. When the engineering team was testing that, they couldn’t believe it themselves–they ran the tests three or four times before coming back to us and saying “No, really, as long as it’s moving we don’t need a rear screen wiper. It doesn’t create turbulence and it doesn’t soil the rear screen.” So that’s, again, another testament to how aerodynamic the car is.
We’ve still got very Jaguar-like, slim LED tail lamps. We’ve kind of evolved that lovely F-type tail lamp graphic, which is the horizontal bar intersecting the rondel (inspired, of course, by the Series One E-type tail lamp). We’ve given it more of a graphical feel, and introduced what we now call the “chicane line,” which is this little line that dives down here. It gives it a bit more of a modern, progressive feel in the graphics of the car. But it still has that sort of slim horizontally-biased tail lamp feel that you’d expect from Jaguar.
Moving down the rear bumper, obviously a Venturi on the rear of the car in the trailing edge, which really does separate the air from the vehicle at that point.
One of the benefits of electric vehicles, particularly the ones that have the battery packs underneath them, is that they have a very clean underflow. When you see one of these cars being built, it’s completely smooth under there, which is great from an aero management point of view.
So we’ve been very capable of managing the air over the top, down the sides and underneath I-Pace to make it as slippery as we possibly can whilst giving it decent cooling, whilst giving it decent downforce at speed. And you will have discovered on the track today that it does plant itself pretty well actually at high speeds on the track.
And because we’ve got quite a square plan shape, it is an SUV, we’ve actually got a very practical load space in the vehicle.
Then there were the challenges of being as progressive on the interior of an electric vehicle as we are on the exterior. The exterior kind of defined itself: We get rid of the engine and gearbox, we pull the screen forwards, we make it cab-forward, you’ve got a statement.
For the interior, we thought really hard about what we could do to make the I.P. (instrument panel), the dashboard, much more differentiated. But the truth is, when you put in the building blocks required of a modern car–an HVAC unit, airbags, knee bolsters, etc. it actually defines a fairly normal architecture for the IP.
Where we’ve had fun is in the center console area, where you need access to the controls for the heaters, you need stowage, you need an armrest, and the car is actually really useful in that respect. The stowage bin in the center console, when you pull out the cupholder lid, you can actually put two bottles of wine side-by-side in there. Or a small ladies handbag, or two large bottles of water, so you get a very big, practical stowage vacated by the area where the prop shaft would be.
Once we’ve launched the car you’ll have capacitive charging underneath the console controls there. The dashboard itself has a large central touchscreen and a digital display that helps you manage the energy and helps you drive in a way that suits your style, whether you want to drive to regenerate, or to drive quickly, you can see exactly what the car’s doing. So we had a bit of fun with the graphics.
We also engaged with some Hollywood-based sound guys to figure out what sound we wanted this car to make when it was really being gunned in anger. At the track today some of you were discussing whether it sounded more like a turbine or an X-wing fighter. Either way you’ll notice it takes on a different tonality when you really go hard on the vehicle, and that’s just to give you the aural stimulation that you expect as a human being when you’re going quickly–you want it to sound like it is doing something more.
Beyond that, we also found that with this–our first electric vehicle–when you take the exhaust note and I.C. engine noise out, you’re left with all of the road noise, the wind noise and so on. So we really focused very intently on making this the quietest, most refined cabin experience you could possibly get in a car when you’re not driving quickly. That’s a Jaguar core value; cars like the first generation XJ were known for their serene cabin environment, that magic carpet ride.
All in all the I-Pace speaks to the core values of Jaguar. It handles well, it accelerates and performs very well, it’s very refined, it meets all of those expectations that you’d get from a Jaguar.
I remember when Ian Callum and I joined the company, one of the visions Jaguar had was that we wanted to return ourselves back to the forefront of automotive design. We wanted to be the progressive company that had inspired us all through the golden era, when (Jaguar founder) Sir William Lyons and Malcolm Sayer (designer of the C-, D- and E-types) were really creating some genre-defining cars. I think I-Pace is our genre-defining car. It really is going to be the tipping point and something that defines the brand moving forward.
https://www.core77.com/posts/78934/Jaguars-New-I-Pace-Part-2-Going-Over-the-Design-Details-with-Production-Studio-Director-Wayne-Burgess