While at my local Lexus dealer having my wife's NX serviced last month, I went up to the showroom to look at a 2021 IS - I have a 2014 IS 250 that I have had for the last 6 years with total satisfaction. After looking at the sticker price and being surprised at how reasonable the IS still is, I started to take a closer look and soon found out how they are able to minimize the price increases after all these years - they are taking "robustness" out of things. The best example of this is the metal thickness of the hood and trunk. When my wife got her NX, one of the first things I noticed was the flimsiness of the hood - you could literally press on the center of it and make the hood give very easily - a really big difference from my 2014 IS hood/trunk which are solid. It seems they have taken that same flimsiness to the IS now - both the hood and trunk on the 2021 were just like the NX now - paper thin. I was shocked when I closed the hood and trunk and noticed how light they were and the hollow sound they made when they closed - feels like you could dent them very easy if you leaned on them too hard.

The IS I have is my first Lexus and really met the expectations of what I thought a Lexus should be - solid and reliable. I hope the removal of the robustness from the new IS is not a sign of future things to come for Lexus - be more than willing to pay a few more dollars to maintain that solid feeling in my future vehicle.

Anyone else notice this change from the early Gen3's to the current ones?

 

I am by no means an expert when it comes to car body construction, so take what I think with a gain of salt if you wish, but I believe I am right on this.

I think it's likely that during engineering and crash testing it was figured out that certain parts (mainly front and rear) of the body being able to crumple to absorb high impact collision provided less impact and more safety for the driver. The less robust panels may not be as good for the car itself in the instance of a crash, but better for the drivers safety.

Most modern cars, the sides and roof are the most robust, whereas the front and rear are designed to crumple in high impact collisions.

It's kind of the same reason we don't see full steel body vehicles anymore, it wasn't just to save cost. Steel body vehicles, while being tanks that could take some damage and come out not totaled, on the flip side almost all the impact inertia was felt by the driver and resulted in more serious injuries and deaths.

EngineeringExplained did a video on this subject a while back and showed how cars are purposely designed to crumple in certain places to absorb as much of the impact as possible, in the interest of saving the driver, not the car. And with rising safety regulations, it makes sense.

 

Agreed with the above. Structural soundness is clearly demonstrated in mandated crash testing.

 

IS parts are really heavy, people are always swapping the hoods (and sometimes even the trunk) for the carbon fiber counterpart. I think it's a good move by Lexus by lightening up the vehicle, IMO, it's way too heavy.

Learned this in physics class, as others have suggested above, before cars were made of steel (and would remain, for the most part, undamaged) which would transfer the energy from the collision into the vehicle causing a higher rate of passenger mortality. Kind of hard to believe but these lighter weight materials are able to absorb and dissipate the energy from a collision better (but being completely destroyed in the process) limiting passenger injury

 

5 star crash rating and longevity are what matters most. The trunk is filmsy, i agree, but the hood isn't that bad imo..

 

If anything, they may have cheapened some parts of the interior, but body? Doubtful. Even the action of closing the trunk feels more precise now. I always thought the trunk rattled somewhat on my 2016 when I closed it. The new 2021? Feels as solid as any other luxury car I've experienced.

The main difference I've noticed is the headliner. It's not as soft as it was in my 2016. However, on the whole I much prefer the new interior. For the most part, it seems perfectly put-together and has good materials.