Home » Cadillac CT4 vs. Cadillac ATS: Exterior, Interior, Cargo Dimensions

Cadillac CT4 vs. Cadillac ATS: Exterior, Interior, Cargo Dimensions

Cadillac CT4 vs. Cadillac ATS: Exterior, Interior, Cargo Dimensions

The Cadillac CT4 is the luxury automaker’s new C-segment sedan that will take on rivals like the BMW 1 Series, the Audi A3, and Mercedes-Benz A-Class, marking the very first time that Cadillac had an entry into the C-segment to take on the aforementioned rivals.

The CT4 draws its roots back to the now-discontinued Cadillac ATS Sedan, which it indirectly replaces. In fact, the CT4 uses the ATS’ general foundation, while significantly changing or outright redesigning the exterior, interior, and mechanical bits. But those with keen eyes will be able to recognize the ATS in the roofline, door shapes and several other hard point areas. So, we thought it appropriate to take a closer look at the CT4 and compare it to the ATS with regard to exterior dimensions, interior dimensions, and cargo dimensions.

Cadillac CT4

Cadillac ATS

Exterior Dimensions

Outside, we find the CT4 is larger than the Cadillac ATS in almost every single way.

Although both models have an identical wheelbase, the CT4 is substantially longer in terms of overall length, adding an extra 4.4 inches over the ATS. The CT4 is also 0.4 inches wider overall and 0.1 inches taller, while both the front and rear tracks are 0.8 inches wider.

To note, the overall width measurement listed here does not take into account the width of the sideview mirrors.

Cadillac CT4 vs. Cadillac ATS - Exterior Dimensions
Dimension Cadillac CT4 Cadillac ATS +/- Cadillac CT4
Wheelbase (in.) 109.3 109.3 0
Overall Length (in.) 187.2 182.8 4.4
Overall Width (in.) 71.5 71.1 0.4
Overall Height (in.) 56 55.9 0.1
Front Track (in.) 60.3 59.5 0.8
Rear Track (in.) 61.7 60.9 0.8

Cadillac CT4-V interior

Cadillac ATS-V interior

Interior Dimensions

The CT4 does improve on the ATS Sedan when it comes to interior dimensions.

Compared to the ATS, the CT4 offers 0.3 inches less front and rear headroom, and 0.1 inches less front and rear legroom. Meanwhile, first and second row shoulder room and first row hip room are identical compared to the ATS. That said, the CT4 does manage to offer more second row hip room compared to the ATS, with an extra 0.2 inches.

The fact that the CT4 does not improve on the ATS Sedan in the interior dimensions area isn’t something that we consider a demerit. That’s because the CT4 is a C-segment car, and has sufficient space for that segment. Meanwhile, the ATS was positioned as a D-segment car. In that regard, it had less room than its direct rivals.

Cadillac CT4 vs. Cadillac ATS - Interior Dimensions
Dimension Cadillac CT4 Cadillac ATS +/- Cadillac CT4
First Row Headroom (in.) 38.3 38.6 -0.3
First Row Legroom (in.) 42.4 42.5 -0.1
First Row Shoulder Room (in.) 55.2 55.2 0
First Row Hip Room (in.) 53 53 0
Second Row Headroom (in.) 36.5 36.8 -0.3
Second Row Legroom (in.) 33.4 33.5 -0.1
Second Row Shoulder Room (in.) 53.9 53.9 0
Second Row Hip Room (in.) 52.5 52.3 0.2

Cadillac CT4-V

Cadillac ATS

Cargo Dimensions

Interestingly, the CT4 features more cargo room than the ATS, with 10.7 cubic feet total. That’s 0.3 cubic feet more than the 10.4 cubic feet offered by the Cadillac ATS Sedan.

Cadillac CT4 vs. Cadillac ATS - Cargo Dimensions
Dimension Cadillac CT4 Cadillac ATS +/- Cadillac CT4
Cargo Volume (cu. ft.) 10.7 10.4 0.3

The Cadillac CT4 broke cover in May of 2019, first as the performance-oriented CT4-V, and later as the “standard” CT4 luxury sedan. It will go on sale in the first half of the 2020 calendar year in the United States, followed by other markets. To note, the CT4 goes on sale in China during the first quarter of 2020.

Subscribe to Cadillac Society for more Cadillac CT4 news, Cadillac ATS news, and around-the-clock Cadillac news coverage.

Written by
Jonathan is an automotive journalist based out of Southern California. He loves anything and everything on four wheels.


  1. Am I missing something here? I don’t understand the concept of making a vehicle bigger on the outside and smaller on the inside. Seems like to me all you are doing is adding weight, cost (for added material) and decreasing gas mileage. After about 42 of the CT4s with the extra 4.4 inches there is enough added material to make a whole ATS. Besides interior space was one of the biggest complaint about the ATS. I heard that the CT4 was suppose to go down in the category it competes in. To be honest I am not so sure what class it is suppose to be in. But in any case adding exterior size without a corresponding interior size increase make no sense to me.

    • AMEN Felix!! Exactly the comment I was going to make! Thx for doing it so descriptively. Virtually EVERY car mag comment on the class-lagging rear-seat room. First thing I checked was for an XT4 exeneded wheelbase of at least a couple inches. Let’s face it, even American kids (likely back-seaters) ain’t little!!

      • The inches gained are more than likely due to styling changes and not the vehicle actually being longer. The wheelbase is where it would create more usable interior space or noticeable dimension improvement inside if it was longer. Wheelbase remains the same so interior dimensions basically and unsurprisingly do as well.

        Also, this vehicle is now in the entry level class so the comments about it being cramped in the class as an ATS are null and void.

        • CHEF CJ
          Not sure I understand how styling changes increase the measurements by 4.4 inches and the vehicle not being longer. To get increase interior dimension usually does include a wheelbase increase. that is what GM did with the new pickups adding a good amount of increase in interior measurements with only a slight increase in exterior measurements. Why couldn’t they do that with the CT4?

        • Correct. The facias of the CT4 are where all the extra length is, mostly in front from the looks of it. The “core” of the car, the passanger cabin, is essentially the same as the ATS. Personally I think the CT4 looks very good. More sleek than the ATS.
          And yes, the CT4 will be competitive with it’s competition now that it’s positioned as a “C” segment car.

        • An undersized D segment runt competing in the C Segment based on price alone. It’s inefficient packaging at best.

          • Price alone????

            The CT4 will be the only RWD platform car in its segment. And while it’s purely a matter of opinion, the best looking offering. Compare it to the Mercedes A, for example. It’s $1K base-cheaper than the Cadillac, but it’s FWD and it’s base engine produces a wimpy 188 HP. The Audi 3 is FWD and its base engine puts out 184 HP. The base CT4 engine gives 237 HP.

            Runt ???

            • I indicated ? ??????? ????; not C segment runt. It’s a vehicle originally designed for the D segment. Vehicles in that class have since moved up in size. Cadillac didn’t keep pace. So we get a has-been vehicle that didn’t keep pace with its intended segment and now competes downmarket. The fact that it’s RWD is its saving grace.

  2. Put the black with a motor in it with a 10-speed car would sell like hotcakes

  3. Alas, no CT4 Coupe to replace my ATS Coupe!
    Now where will I have to go for a Coupe?
    Back to a Camaro? Been there, done that.

    • Glue the two rear doors shut. Then you have a two-door CT4.

  4. The issue about the headroom difference is moot, because you did not measure seat heights, nor take in consideration the seat and back adjustments that drivers do according to their driving style. So if a CT4 driver sits lower, the headroom increases. I prefer a higher seat height and I raise my seat as high as possible for a better road view (I am 6 feet tall). So headroom is moot for me, too.

  5. It seems to me they are comparing two different classes/segments here………the ATS was in the segment of the C Class MB, 3 Series BMW, and the A4…….the CTS was in the segment of the E Class MB, 5 Series BMW, and the A5/A6…..to quote Car & Driver in their comparison of 10 Best……”they’ve taken out all that was good about the ATS and CTS and added NOTHING to the mix”…..

  6. They made the exterior dimensions about the same size as the ATSL(built for China market to give more rear leg room 3.3 inches I think it was)..BUT the CT4 they give 1 TENTH OF ONE INCH LESS for the North American market.How bizarre is that?

    • Leaves you scratching you head. More length more weight and no interior room improvement. Not just no interior room improvement but a reduction in just about every area measured. We know they know how to increase interior room because they made a significant increase in interior room in the pickups with just slight exterior dimensions increases.

      The ideal thing would have been significant interior increases with a reduction in exterior dimensions. Even with the same exterior dimension with increases in interior to exceed its competition would have been better. But what the heck do I know I am no engineer just a bloke with common sense.

  7. I would like to know from Cadillac why there voice recognition software for the on-board guidance system is so bad. I am forced to plug in my phone and use The Android Play function to access google maps that has not voice recognition problems. I own a 2018 CT6 Platinum and ever since i purchaced this car I have complained about the Caddy voice recognition software. Why dont they just team up with Google and use their system which is easy to use and finds what you need in seconds. I purchased this car due to Super Cruise and am waiting till this super useful feature is offered on the next gen escalade. Please reach out to Cadillac and find out why they have such a pour piece of software in a $90+ car.

    • When was the last time any of you bought a car because it had a half inch more rear legroom than another?

      Go on line (edmunds.com is a good place for this) and check the interior dimensions of C segment luxury sedans close to the $33K starting price of the CT4. Audi A3, Mercedes A etc.

  8. IMO I think Cadillac would have better served to keep the CT4 in the same class as the C and 3 class and added a couple of inches in wheelbase and make the interior space at least 1/2 inch bigger than theirs in all areas. Then you add a more powerful engine a bigger trunk and an interior that at least match theirs in quality and style. You charge a price that is appropriately lower than theirs and brag with Cadillac you get more for less. They need to apply that strategy across the board in every vehicle they make. They don’t need to try and compete with the competition lower class vehicles. GM has too many division to have their their so call top of the line diversion competition in Mercedes low end class where Mercedes has only one division to try and compete in all category’s. Before any get offended remember how I started with the letters IMO. No exper in marketing an certainly no engineer.


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

Lost Password

Please enter your username or email address. You will receive a link to create a new password via email.

Sign Up