Effect of weight reduction on performance

This is one such interesting video, where it presents an opportunity to understand how much the individual parts in a car weigh and to make some informed choices, when ticking the variants/options boxes, when we buy a car.

BHPian carthick1000 recently shared this with other enthusiasts.

I am fan of lightweighting philosophy when it comes to car design. Recently came across an interesting video by ChrisFix, where he goes on to reduce the weight of an E46 to prepare it for track use. Of course track cars are stripped off to bare essentials before making them race ready. This is one such interesting video, where it presents an opportunity to understand how much the individual parts in a car weigh and to make some informed choices, when ticking the variants/options boxes, when we buy a car.

Some of the observations and takeaways in general

1. Being someone who DIY maintained an E90 myself, I cannot stop wondering how every generation of BMW is engineered with maintenance in mind. Tabs that wont break, torx screws for plastic parts, easily accessible fasteners but hidden to plain sight.

2. Sound deadening only at places which makes sense.

3. Heavy padding and carpets inside cabin, which is one of the reasons to own a luxury car and why people like them. The one other brand which obsesses with sound proofing is Lexus. See what they do with their entry level model. Now one can imagine what they would have done with their flagship model.

4. Accelerates faster, corners nimble (fun) and stops sooner (safety) and uses less brakepad, when a car sheds it's weight. Also helps in downsizing of several other components, which in turn improves fuel economy. However in this case, the weight reduction is done for a different purpose.

5. Motorised seats are super heavy and complex things. Most of the times, people adjust the seat once in a blue moon and the amount of spare parts gone into making an electrically adjustable seat is way too much compared to a mechanically adjustable one. Unless there is a need, keeping lesser complexity in the cars is easier for time and wallet.

6. 196 kgs reduced in total. I will not reveal the other numbers, as it spoils the viewing experience.

With improvements in materials and new simple (less complex) drivetrains, the whole car's weight can be reduced to make them fun and safe. Hope we will see such car designs in future. Feel free to add your observations to make it an interesting and informative thread.

Here's what BHPian TrackDay had to say on the matter:

Weight reduction is definitely what has been going around in the car industry for quite some time right now. From adoption of materials like aluminum, carbon fiber etc. manufacturers in the recent years have found way to make cars that are more efficient, not just in terms of mileage, but also safety and handling.

While all that is good, added features in newer cars might also increase weight. For instance, panoramic sunroofs not only are heavier, but also affect mileage due to increased AC consumption. Music systems are going from more than 4 speakers, while motorized seats add weight to the car.

Then there is also the case of undesired weight reductions in the form of missing spare tyres!

Here's what BHPian gkveda had to say on the matter:

It is true, as per physics laws, acceleration and braking would be more effective as weight reduces. But we should be aware that manufacturers are already at their beyond optimal levels in designing the cars with light weight. Ex: Engines are made from aluminium instead of iron, monocoque designs instead of on frame body (except few cars), sheet metal used have less gauge, etc.

And the negative side of reducing weight is, the stability the car offers reduces drastically. At high speed, you will never get comfortable if the car is light weight. So, if you want to have some benefits, you have to compromise on something else.

Hence, the best solution to this problem is, to keep the car stock and trust the manufacturer has optimised the car for performance and stability by design. Also purchase car from a trusted manufacturer.

I align with OP points about requirement of few accessories like motorized seats, panoramic view. In my view, They are not needed for a car. But not from the point of view of reducing weight. As rightly said, to change the seat position once in a blue moon, I can not afford to spend more than 10-15k as dead capital. And to see the nature that is freely available for entire universe outside of the car, why should I pay a lakh or more to the car manufacturer? And then, create multiple posts in social media to crib about the leakages and other related issues?

Here's what GTO had to say on the matter:

Great for track use & drag racers, but absolutely pointless for on-the-public-road usage. I'd rather have 100 more kilos and enjoy the amenities 99% of the time than have the benefits of weight reduction 1% of the time.

Drivers doing it for the sport should also reduce their own weight . Easiest way to make your car 20 kg lighter is to go on a healthy eating diet.

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