ATTI gets a progress update on the CT5’s refresh from its new chief engineer, Alex MacDonald
Amid the ongoing push toward an all-electric line-up by 2030, gasoline-powered sedans are still doing the business for Cadillac. Sales of the mid-size CT5, for example, are at their highest level since the car was launched four years ago, with the brand as a whole enjoying record sales in 2023.
Cadillac plans to build on this momentum with the refreshed 2025MY CT5. Almost two years ago, chief engineer Alex MacDonald (pictured opposite) moved across from a role as vehicle performance manager on Chevrolet’s performance cars to oversee the facelift through to production in early 2024.
Attention to ADAS
The revised CT5 will feature intersection emergency braking and side blind-zone steering assist. Despite those systems already seeing service on other GM vehicles, there has been plenty to do.
“Probably the biggest stretch for me is adding the luxury ride requirements and the active safety systems that we don’t currently have for the most part on RWD performance cars,” says MacDonald. “We’ve all driven cars where you’re interrupted by braking events, or beeping, or fighting the steering. We’ve tried to make sure these systems work with a car that’s built to be driven a little more spiritedly.
“We have a great facility at the Milford Proving Ground to very carefully orchestrate all those systems together,” he continues. “Little details, like the angle at which you mount the radar sensors in the fascia and fenders, require custom tuning to make sure that you’re identifying the [activation] zones properly. Changing their position just a couple of degrees in the [styling] refresh meant we had to go through and remap where they are in the sensor set. It’s fun work tuning that because you’re driving really close to other people!”
With constant pressure on vehicle makers to reduce development times, MacDonald believes this type of detailed work sometimes gets cut from the test schedule. Not at GM, however.
“We don’t see that [attention to detail] in all of our competitors,” he offers. “Some of those competitors that are coming to market faster might say, ‘These two brake calipers are similar, we’re going to share an ABS calibration for these two cars.’ The average consumer is not going to notice. But we are very much into the integration of those details, making sure that if you buy a different tire, you’ll get a different calibration in your ABS or your suspension to make sure that is optimized on the car. And that’s where some of that time goes. You have to decide, are we going to budget time for that or are we going to race to market as fast as we can? It’s a balance.”
Agile advantage
Faster software development cycles (see Crack the code, ATTI June 2023, p36*) are another new frontier affecting programs at GM, including the CT5. The refreshed sedan gains a 33in wraparound screen featuring built-in Google and Amazon Alexa.
“I have a ton of experts on the team developing these features until they’re ready to undergo testing,” comments MacDonald. “My contribution is more to be the voice of the customer, [seeing] how those features work when you’re in a dynamic situation, in a way that is engaging and not interrupting.”
He describes agile software development practices as “a new paradigm” for all automotive manufacturers, enabling features to be introduced as close as possible to the start of production.
“It gives us a lot of flexibility that we didn’t have before,” he explains. “But you also need to rethink your expectations at each milestone. We work closely together [with the software team] to make sure that we all understand the timing, understand when it is okay for us to say that details need to be fixed on something that should be finished.”
An early preproduction car from the plant in Lansing, Michigan, was on display at Detroit Auto Show in September. The week before, MacDonald had taken part in a “100% ride” in a similar car.
“For that particular ride, the written expectations are that it’s done. Earlier rides might be missing a calibration that won’t be done for another two months, for example. This time we were able to say, ‘Okay, everything’s finished,’ which was really gratifying.”
