BMW i3 vs Cadillac CTS – Impact Results

2 years ago by Warren M 79

Picture of my i3 after being rear ended by a Cadillac CTS

Picture of my i3 after being rear ended by a Cadillac CTS

Yesterday I was rear ended by a driver who sped through a stop sign and apparently didn’t notice me in front of him. His Cadillac hit me so hard I ended up 175 feet from the point of impact.

The impact was so hard that the center console arm rest flipped straight up and broke the latch. My seat back was even bent with the rear cover popping off.  So a violent crash to say the least. But with no broken bones or cuts, this could have been much worse for me. They took away the passengers in the Cadillac by ambulance also, but there condition is still unknown at time of press, though obviously their airbags deployed.

Cadillac CTS after impact

Cadillac CTS after impact

Remarkably, the BMW doors all open and shut normally. Even the rear hatch released with the remote and closed normally.

While lying in the ambulance, I heard the first responders saying “I can’t believe how bad the Cadillac looks compared to that BMW!”

A testament to the safety engineering that went into the BMW i3.  Kind of sad this happened to my BMW which was less than 2 months old with 1600 miles on the odometer; and I don’t look forward to the hassle of dealing with the other driver’s insurance company to get me on the road again.

Editor’s Note:  Out of some concern we did follow up with Warren today when we heard this news, just to check in on his status, and he reported back he was A-OK

“…im okay. Ambulance was a precaution because of sore neck, ankle, and elbow. Did a cat scan at the hospital, nothing was broken. Took some muscle relaxant at the hospital and pain medicine. Feared I would feel horrible when waking up this morning, but okay. I plann on taking it easy for the rest of the weekend to make sure the aches and pain go away.  Considering how light the i3 BEV is compared to a CTS, it fared pretty well.”

My i3 ended up 173 feet from the point of impact

My i3 ended up 173 feet from the point of impact

Spot where the Cadillac came to rest

Spot where the Cadillac came to rest

The violent force bent the seat back and dislodged the seat back cover. Center armrest went straight up, with the lid latch broken

The violent force bent the seat back and dislodged the seat back cover. Center armrest went straight up, with the lid latch broken

As is often the case, Warren’s most recent modification on the car, a nifty rear bumper modification (which you can read about here), appears to have taken the brunt of the impact.

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79 responses to "BMW i3 vs Cadillac CTS – Impact Results"

  1. SparkEV says:

    Terrible news! Glad that Warren is ok, and I hope for speedy recovery for others. I was excited for Warren on his i3, sad to see it go so soon.

    It seems crumple zone in front of Caddy is more pliable than i3 rear, even with all that metal (gas engine). It looks like Caddy will be total loss whereas i3 might be fixable.

    1. John says:

      With the force of that impact, I’m sure there is a lot of damage you can’t see…
      But it’ll make a great parts car for someone!

    2. evcarnut says:

      The Cadillac folded like a cheap tent…Glad everyone was un-injured

      1. fotomoto says:

        “Crumple zones are designed to absorb the energy from the impact during a traffic collision by controlled deformation.”

      2. Tech01x says:

        It should fold up. The point is to reduce the g-forces of impact.

        1. evcarnut says:

          we are aware…………

  2. Chris B says:

    No way is the i3 fixable… Will be totaled for sure with that level of impact (based on drivers description).

    1. evcarnut says:

      BMW looks very intact .. the cadillac not so much..there is a difference between crumble zones & aluminum foil..The cadillac needs the crumble zones Beefed Up some. There is TOOOO Much Un-necessary Give…

      1. Yup says:

        The right amount of give is the maximum amount that reduces the impact to the passengers, while not intruding into the passenger area. What part of the crumple that you see do you think is unnecessary? Do you honestly think that it should have crumpled less, thereby injuring the passengers more? Why?

  3. R.S. says:

    After those pictures, its not hard to see that the BMW is a very safe car. The Cadillac id what it was supposed to do, crumple, but from the picture its hard so see if the crumpling was done safely.

    1. Tech01x says:

      No way you can tell that by the pictures. The real question is the g-forces… throw away the car to have lower g-forces. I expected the i3 to have a better crumple zone.

      Luckily, he had 175 feet of clearance after impact – if he was pushed into traffic going across or into another car, there would be a secondary impact that may be much worse.

      1. Alpha777 says:

        And airbags.

  4. James says:

    First, hope the other driver is okay. Second, I’m interested in how the i3 absorbs impact and keeps that energy from harming the driver. In this case it was, perhaps, better that it bounced instead of crumpled, but had there been a car in front of the i3, I’m concerned about how the driver would fare vs. a more conventional car.

    1. The i3 scored very well in NCAP crash testing, specifically for driver and passenger crash protection. It even scored higher than the Model S in those categories.

      1. Unplugged says:

        The various testing agencies don’t test rear-end collisions. We won’t know how the i3 does except by individual results such as this.

        1. Alpha777 says:

          …don’t test rear collisions…

        2. D-J says:

          Rear crash test @

  5. Insane Electric Torque says:

    Like I said before i3 is like soap-dish on wheels. The egg is hard but fragile inside.

    1. evcarnut says:

      Poultry in motion.. l m a o

    2. Stimpy says:

      Read the comment above yours. i3 scored higher than Model S on passenger protection.

      1. Unplugged says:

        But does any crash test you refer to incorporate a rear-end collision such as this?

  6. evcarnut says:

    BTW,, was rear Ended 6 times …N0 Joke about it. The Effects last Forever. I just don’t like to dwell on it & make things worst .

    1. Will says:

      you’ve been rear ended 6 times? Seriously, do American drivers simply not look where they’re going?

      1. evcarnut says:

        Canadians Don’t look where they’re going & 2 of them were DRUNK…maybe the beer here is tooo strong…after after hands still numb up..

        1. Drew says:

          This is why I’m a huge advocate of automatic braking systems. We’re not all Mario Andretti or Jeff Gordon out there.

        2. sven says:

          Stronger beer would also explain your random use of the Caps Lock button while typing.

          1. floydboy says:

            Thanks Again sven.

            as Always, your negative Input Is invaluable.?

  7. Kaleb says:

    Did anyone else notice that the driver’s side appears to be pretty heavily damaged? You can see the panel bowing outward–just curious how that side of the car looks.

  8. Ken_3 says:

    The author said that the rear hatch still functions. I believe it’s repairable. The Caddy, probably not. Hopefully all the occupants will be OK. We are not very repairable. Injuries do come back to haunt you as we age.

  9. Three Electrics says:

    This is as expected. The front of the car is a crumple zone; the back is not. Thus, the front of the CTS crumbled and the back of the i3 did not.

  10. pjwood1 says:

    Hope all ok.

    A similar rear-ending is how i now describe P85D acceleration. It’s more like an accident, than another car.

  11. Tom Moloughney says:

    Just happy to hear you’re ok, Warren. That’s really all that matters.

    1. Josh says:


      The i3 did its job. Hope you are back in a new one soon Warren.

    2. Pushmi-Pullyu says:

      I’ll happily join this chorus!

      Glad you were not seriously injured, Warren.

  12. Sal Cameli says:

    Yes. As other have said. Hope you are all OK. Cars can be replaced. I’m not surprised at all that the #BMWi3 has such little damage. Modern Techology will always win over old technology.

  13. Andrei says:

    I think NHTSA and NCAP make a major mistake when testing front crashes by not including a test in witch the care is braking for the last seconds.
    The reason for this kind of test is that the car performs different when braking, the front of the care is leaning and the back is getting higher. the center of gravity is shifting forward in this way putting more stress on different components.
    I have been involved in such a crash and none of the safety features worked except for seat belts. No airbag deployed when I rear ended a car because that car had a shorter braking distance then my car. The damage to my car was extensive but only over the bumper (grille, headlamps, hood, fenders). The other car was an SUV with a bigger ground clearance them my car, the damage to the other car was located only in the lower and underneath the rear bumper aria. The SUV was braking too at the moment of the crash and it was leaning forward with the back higher then normal when I rear ended it. I think if the crash happened at greater speed in the same condition I would have been injured.

    My opinion is that in a lot of crashes the driver has the time to push the brakes but it is to late, and this scenario must be consider, because it is an uncovered real life test like it was with the small overlap test.

    1. pjwood1 says:

      Didn’t BMW just withdraw the American i3 sport, for reasons that included suspension (too low)? Your point is well taken, and bumper height rules are different, US vs. Euro.

  14. tiburonh says:

    Very sorry this happened to you Warren. Glad the i3 protected you so well! Don’t forget to include in the insurance claim the cost of getting a new bumper panel on your new i3! Stay safe.

  15. Max says:

    A regola si è fatta meno la i3, spero non si sia fatto davvero male qualcuno degli occupanti dei due veicoli…

  16. WARREN says:

    I wish I could have seen this in slow motion. But who knows, perhaps the CTS was almost scooping the i3 up from below, and perhaps briefly lifted the car up. This is where a low cg, from having the battery pack on the bottom could keep the car from tumbling. There are some broken smaller carbon fiber pieces, so perhaps this might be more costly to fix than anticipated. Apparently it has to go to a special certified repair facility. So will be a while before I get any hard estimates.

    This is also a reason you need GAP insurance. The insurance company might often try to just pay the cars blue book value, leaving you exposed to the amount owed to the bank. But since it was his fault, I might have to get an attorney if they make it impossible to restore me back to pre-accident condition.

    1. ffbj says:

      Wait at least a month before you sign anything.
      Sometimes it takes weeks for residual physical damage to present. Wait a month, get a CAT scan, and see another doctor.

      1. sven says:


        Soft tissue injuries sometimes first manifest themselves up to three days after a car accident (maybe longer).

    2. jerryd says:

      Warren, I design, build 3wh, 1 rear wheel cars and was reared ended at 25mph built out of epoxy/plywood.
      But it was designed to raise up letting the car slide under me with little damage and only cost me $40 to rebuild.
      The compact car though was totaled as my main center beam went right through their radiator, etc.

    3. Jeremy says:

      Fwiw, if you lease through BMWFS, it includes GAP instance already

  17. doug says:

    Interesting. Seems a good deal of energy of the impact was transferred to kinetic energy moving the i3. Was the driver’s foot on the brake? What is the status of the drivetrain?

    1. Pushmi-Pullyu says:

      doug asked:

      “Was the driver’s foot on the brake?”

      Which driver? If you mean Warren, the violent impact would have thrown him backward — note the damage to the seat — which would have removed his foot from the brake pedal. So yeah, that’s why the car rolled 175 feet; there probably wasn’t any braking involved after the impact.

      That’s not just physics; I write from my own experience when the car I was driving was rear-ended.

    2. Nix says:

      I wonder if the aggressive regen of the i3 would actually help in this situation. With the brake basically being automatically applied partially with the strong regen when no feet are on any pedal.

  18. Pushmi-Pullyu says:

    I am absolutely gobsmacked that a collision that violent — just look at the Caddy! — didn’t even break the rear window of the i3.

    The next time someone claims that the CFRP (Carbon Fiber Reinforced Polymer) body of the i3 is brittle and will shear or snap on impact, I’ll simply give him a raspberry!

    1. Will says:

      CFRP is carbon-fibre reinforced plastic, not polymer. Anyone who claims it’s brittle is an idiot, plain and simple. It’s very strong.

      1. Heisenberght says:

        Am I a half – idiot?

        It can be brittle AND strong… Can’t it?

        Well it’s a composite… Plastics (yes most (all) plastic is polymer…) can have very very very differing properties… They can be stretchable (think household foil for food) and can be brittle (think Plexiglas) heck they can even have differing modules of deformation for different axes (quite high tech) furthermore their properties change extremely depending on how far they are from glass transition temperature. I won’t start to talk about additives and side effects…

        Carbon fibre also has different modules of deformation for different axes. Different fibre strengths can be used. Different geometry of fibre grid also has an influence…

        I doubt anyone here has deep enough insight into the exact composition of that composites BMW uses to make any claim about the physical properties.

        To put it simple: BMW (or the company which developed the composite) did a good job to protect Warren. That’s the one thing that matters.

    2. Aaron says:

      It looked like the Caddy was braking hard and slid under the i3 a bit. That would explain the (1) long distance to stop [with only 2 wheels on the ground (2) rear window not being shattered (3) relatively small amount of damage to the fascia of the rear bumper. There could be a lot more damage to the underside of the i3, especially if it was a REx.

    3. jerryd says:

      PP, if you knew how it was built you’d know the alum frame took most of the forces.
      CF is more brittle and personally as a composite expert I wouldn’t use it in cars.
      Instead FG and Kevlar like reinforcement fibers and lots of foam are much better in a crash, weigh and costs less.
      Will, it is a polymer resin as most if not all plastics are.
      Fact is 1/3 of the CF is in nylon like plastic in the i3.

      1. franky_b says:

        You should give a call to BMW and tell them how little they know.

        1. jerryd says:

          franky,, Frankly I’ve been at it longer than they have with 50 yrs of composite vehicle design, and production.
          Fact is compared to what I normally build, a car is a small lightly loaded vehicle.
          For instance no reason BMW couldn’t build the i3 in 1500lbs or so if they left off the overweight alum frame/batterybox and crash structures.
          Designed right there is no need for the alum as composites can handle all loads better designed right at 60% of the weight, cost.
          And they are corporate engineers driven by fear and not great bosses doing some things the corporation doesn’t want to do, composites and EV’s.

  19. Steve says:

    Nice, but very disconcerting that the i3 ended up 175 ft from the point of impact. I think that’s mainly why it faired so well. It’s lighter so it basically got pushed away instead of crumpling. It’s a good thing it wasn’t pushed into a busy intersection or in front of a train…

  20. Tinbender says:

    Do not be deceived folks, the picture does not reveal the whole story here. Having worked with carbon fiber and fiber glass and aluminum on aircraft for years as a structural mechanic (Coast Guard) not all damage shows immediately. Think for a moment if you will if you slide an aluminum can into the back of a big wet sponge with force. Both are going to give depending on the impact but how much energy travels away from the initial impact area and how much will the materials spring back to their original shape is different, and as we see here BOTH systems did their job well –Protect the occupants at all cost. Yes the caddy looks bad, it is supposed to, remember save the people not your pride. The Beemer’s carbon fibers are broken I guarantee but they will snap back sometimes close to the original position but still be broken. Reason for replacing a “skid lid” following any cycle accident (peddle or motor) because not all damage is visible. Good thing most of the energy was dissipated on the rear end and did not travel and split the car into sections like the “good ol days” and spill the occupants onto the roadway. The caddy was the aluminum can, she did her job well and kept those forces localized to the front area, away from the occupants, Gold Star awarded. Personally I prefer if I am going to play “crash dummy” to be in the newest, safest built cage around me. That’s my 3 cents. Carry on.

  21. Adam says:

    I’m confused about the drivers thoughts of dealing with the other insurance company? I don’t know about the US, but here in Australia, as long as you are insured, you would only make acclaim with your own insurance company and then they will chase it all up, isn’t that what your paying for???? It doesn’t even matter if they are in-I sired, your car gets fixed, and your insurance will spend time suing them.

    1. wavelet says:

      Not quite, not even in Oz, AFAIK from renting there.
      You can submit a claim to your own insurance company, as you suggest, only if you have comprehensive insurance, but that’s not a legal requirement anywhere I’m familiar with.

      Most countries/states require only 3d-party medical liability (that is, damage to other drivers/passengers/pedestrians/cyclists), sometimes also 1st-party medical (damage to you) and, rarely, also 3d-party property damage, but that wouldn’t cover damage to the car itself.

      Now most likely Warren does have comprehensive, since the i3 is a somewhat expensive, new, car.
      However, all car insurance policies I’ve ever encountered raise rates by quite a bit in case of any accident-related claim (no matter who was at fault), or have a hefty deductible (over here it’s typically $500-$1000), usually both. That means that at the very least one should consider making a claim against the at-fault driver and/or his/her insurance, before submitting a claim to one’s own.

  22. Nix says:

    On the positive side, there was absolutely zero passenger zone intrusion. That is very, very good.

    “The impact was so hard that the center console arm rest flipped straight up and broke the latch. My seat back was even bent with the rear cover popping off.”

    A larger crumple zone MAY have reduced how much energy was transmitted into the passenger compartment. Stuff in the passenger compartment being impacted that severely is not a really good sign.

  23. WARREN says:

    Things happen so quickly, you barely have time to react. But for being hit slightly offset, it is a miracle the i3 stayed stable and didn’t dart off the road into a tree. I mean, you see how easily a pit maneuver can throw a car off line. To be hit like this and go straight down the road is really impressive, or lucky. This also is a reminder not to leave loose items such as laptops, tools, etc. The amount of G forces from even a 30mph impact is so tremendous, even a 1.5lb book can kill you. Tools can go through your seat. And most importantly realize, you can be stopped at an intersection, etc. You just never know when you can be the victim of a rear end impact. I have an old 1984 Civic S hatchback on the side of my house. 1970lbs. I can honestly say the Cadillac would have demolished it in the same situation.

  24. Tim says:

    I wonder if the Cadillac driver would have seen him if he still had the white bumper..?

    1. Tinbender says:

      I was thinking those exact thoughts several weeks ago when I saw the blacked-out rear end of a BMW i3 in my neighborhood. I want to be seen.

    2. Sam EV says:

      That was my thought as well. It looks a lot less visible in photos after the bumper modification.

  25. Elroy says:

    Well it was definitely a thought when I was first going with Fluid Black. Though I still would love to have a black i3.

  26. Dan says:

    All this shows is that the i3 doesn’t have a rear crumple zone. If it had been reversed, the Caddy would not have been tossed hundreds of feet out. Instead, it would have taken the damage in the rear. That’s what cars are supposed to do. Cars that maintain their shape the way the i3 did in this crash will result in drivers turning to goo on the inside if the crash is more severe.

    1. WARREN says:

      If the Caddy weighed nearly 1000lbs less than the car rear ending it, it would definitely be tossed forward. The rear end of a hatch back has minimal crush room to begin with. There is no long trunk space. If you have children in the back, the last thing you want is cabin intrusion from crumpling. I have seem hatch backs fold from getting rear ended, and occupants trapped in side because the doors won’t open. Contrary to believe, the drivers side looks remarkably well to, with just the quarter panel unclipped from the upper rear area. The deformation occurred behind the lower bumper cover area, just as BMW designed it.

      1. Gary says:

        Warren, did the accident have anything to do with your ACC cutting out as it has with so many i3 owners?

        1. Warren says:

          No, I had just made a right turn out of my neighborhood and was still accelerating up to speed.

          1. Gary says:

            Thanks, Warren. I hope you are doing well. I have had many times when my ACC cut out. Once going 65 mph with a car behind me. I love my i3, but I believe that the ACC is too dangerous to use at high speeds. One guy reported that he had the same thing happen with the CC even though my BMW dealer said that would not happen. Bottom line, I love 98% of my i3, but will not use ACC at high speeds when the sun is out which is often here in Las Vegas. 🙂

  27. James says:

    Warren, great to see you’re OK, like Tom said above – truly what is most important.

    There is innuendo here that the i3 was super tough, and it seems it’s structure did work for such a small car to retain it’s shape with doors opening. In a rear end collision there is not closing speed of two cars heading towards one another combined. This helps a lot, especially – as others have said, in a situation where the small car has no large crumple zone. I think both cars worked as designed – to the benefit of you all.

    Warren – keep us posted on the end result to your i3. In other words, the cost of repair or if your car was a total in the eyes of your insurance company.

  28. James says:

    As Pushmi said – the force of impact pushed Warren and his seat back, bending the seat and lifting his foot off any pedals. This was a good thing – and a good thing nobody was in front of Warren, causing a chain reaction pileup. This allowed Warren’s i3 to be punted forward a long way! This is better than hitting a stationary object that doesn’t move, it’s a “smack”, rather than a “smash”, if that makes sense.

    A 2014 CTS is 4072 lbs. with V-6, compared to the i3’s 3571 lbs. as BEV/ 3813 with ReX.
    So if the driver in front can avoid a neck or spinal injury, it can be seen how this could have turned out worse in different circumstances, i.e.- more speed and/or car in front stuck in traffic.

    Smaller car = smaller crumple area = more shock on impact. It makes one ponder the upcoming Bolt EV. Similar or slightly smaller car – Honda Fit sized, with not a whole lot of space between rear “bumper” ( if you can call those bumpers ) and rear passenger area.

    Me? I like crumple zones. The sheer space allows for a progressive absorbtion of the crash force – who cares if the car is damaged, I want the occupants to get out of it as best as possible. Make sure the airbags aren’t Takata… lol… and we’re good…hopefully.

    The damage to Warren’s BMW looks pretty minimal, but you can bet the underlying structure has moved or bent, and will need straightening or result in a total of the whole car. The rear window survived, but sometimes will have to be replaced as the seal area can be chipped/cracked minutely on it’s edge. The plastic parts aren’t overtly more expensive than OEM BMW steel body pieces, but it’s the proprietary ( has to be done at a BMW dealer ) body repair, welding and gluing CFRP is going to cost somebody a pretty penny. Don’t believe BMW when they tell the IIHS i3 costs the same to repair as a steel 2 Series. No way! That training, those jigs, glues and special techniques don’t come cheap.

    1. WARREN says:

      Protecting the safety shell is the main priority in a small hatchback with minimal crunch space. Think of the Smart Car TRIDION safety cage. Incredibly strong and stiff for a good reason. The don’t want that cage to crush at all costs. Protect the occupants inside with the usual measures. The i3 has knee air bags, front airbags, side head curtains, etc. In addition. the car is big and open inside. Your knees aren’t even close to the dash. You can’t even reach the windshield far in front of you. These are all parts of the safety design elements the engineers planned into the car.

      Also, the i3 is nowhere near 3571 lbs. That is heavier than a LEAF! It also has close to the ideal 50/50 weight distribution. Here is a quote from the Car And Driver test results in its comparison with the B Class:

      “carbon fiber shows off the radical structure of the car: a composite cabin sitting atop a welded-aluminum skateboard chassis. It’s also apparent on the scales, where the i3’s 2853 pounds undercut the B-class by more than a half-ton. BMW has placed the heavy battery low and at the center of the car with the electric motor slightly above and forward of the rear axle. So, the i3 has a slight 51.8-percent rear weight bias while lightweight body panels keep the center of gravity low—like a proper BMW.”

  29. ModernMarvelFan says:

    I think the 170 ft of rolling is what helpped.

    If the i3 was locked in place, the damage to the i3 would have been far worse as all the momentum would have been transferred to the i3 as it is lighter than the CTS by a huge margin.

    Either way, I am glad both drivers are doing okay.

  30. Jake says:

    This is “Jake” from state farm. Please tell the readers how your car really held up in this accident. I believe your car is totaled. Those pictures are completely misleading and you know it. Please provide an additional photo of the carbon fiber plastic structure damage. Your appliance on wheels does not impress me.

    1. Warren M says:

      Well, give me your email address and I will send you a picture of the other side showing how it looks almost perfect too. Furthermore, the parts total so far is very cheap. And if you are really from State Farm, you should already know this. But since the car is so new, I am on the fence of whether I would prefer they just replace the car. On the other hand, I think just about any other small hatchback car would be totaled anyways. So why would this be any different? Of course the i3 absorbed energy under the bumper cover. But the point is, the integrity of the safety shell held up wonderfully. As a matter of fact, the insurance adjuster looked at a picture of the Cadillac, and said he was seen rear seat passengers die in similar size/weight cars as this i3 when they got rear ended.

    2. WARREN says:

      FYI Jake, Brendan State Farm looked at the car yesterday. He thinks it looks fairly easy to fix. Then after seeing the Cadillac pictures he said “This i3 is built like a tank!”. He said he has seen people rear ended in little hatchbacks killed in an accident like this.

  31. Gary says:

    Warren, can you give us an update on your car? I’m deciding whether or not the i3 will be safe for my pocketbook if I decide to lease or purchase the car.

  32. Tim says:

    Warren, did your body shop take on the repair. Very curious to see the cost of having the i3 repaired due to this type of accident. I have watched the numerous youtube videos of government testing, but I’m not convinced the i3 will hold up well when subjected to real world accidents verses staged in house testing. Please keep us updated on the progress of the repairs. Your car and photos have been added to the facebook page for i3 vehicles to see if there are others who may have sustained identical damage and their feedback results from insurance companies and whether they were forced to deal with BMW body shops or had the option to choose a local independent body shop.