If you go by exterior specs, the Cadillac CT4 is more similar to a BMW 3 Series or Mercedes C-Class. However, if you go by interior space (or price), it’s more like a Mercedes A-Class or BMW 2 Series Gran Coupe. That’s definitely true of the trunk, which measures a rinky-dink 10.9 cubic feet, according to GM’s specs. That number is what you’d expect in a small luxury coupe rather than a sedan. Indeed, the old ATS Coupe had 10.4 cubic feet.
Nevertheless, the CT4 is somehow not the smallest in the segment. That would be the A-Class and its 8.9-cubic-foot trunk. Good grief. Now, Mercedes has been known to shortchange its cargo capacity numbers so we’ll have to luggage test that at some point to know for sure. Today, let’s see if the CT4 is in keeping with that 10.9 number. Also, how much worse is it than the also rinky-dink CT5 trunk or the overly optimistic 2 Series Gran Coupe?
Yep, that looks pretty small. Also, note the weird rail-like things that hampered the CT5 (below right) are also present here in the CT4 (below left). There’s also a similar lip to clear for the folding back seat, but the CT4’s opening seems bigger.
As in every luggage test I do, I use two midsize roller suitcases that would need to be checked in at the airport (26 inches long, 16 wide, 11 deep), two roll-aboard suitcases that just barely fit in the overhead (24L x 15W x 10D), and one smaller roll-aboard that fits easily (23L x 15W x 10D). I also include my wife’s fancy overnight bag just to spruce things up a bit (21L x 12W x 12D).
All but the biggest bag fit, which is exactly the same number that could fit in the CT5. As the below photo shows, the bigger car has just a bit more space left over. Maybe for a pair of grocery bags. That would be consistent with the difference in cubic feet: 11.9 cubic feet versus 10.9.
What about the BMW 2 Series Gran Coupe? BMW says it has 15.1 cubic feet of space, but it doesn’t. At least not using the same measurement criteria that the vast majority of other manufacturers use. It can carry the biggest bag, but it would still need to leave the fancy bag behind. That’s also while utilizing the 2 GC’s ample under-floor storage compartment.
As such, the CT4 does indeed have a small trunk, but it’s at least in keeping with its competitors. The CT5 cannot say that, regardless of which segment you compare it to.
Unfortunately for the CT4, though, the story does not stop here. When I popped the trunk, the goose-neck hinge came out beyond the mouse-fur-covered trunk lining. Every time. Not good.