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Comment by iramiller | Hacker News Reader

This would be easily solved if car manufacturers cared at all… simply cover the bottom of the car with panels. A side benefit would be the increased fuel economy from the cleaner airflow and reduction in drag (this is an inherit benefit of electric vehicles—-especially trucks). It’s not done because no one looks under their cars and it’s easier/cheaper to manufacture and design for cooling.

I should add that installing a simple piece of metal cut to fit over the bottom of your vehicle isn’t a great idea if it doesn’t properly account for the changes in ventilation and cooling that it causes.

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We're starting to see changes in vehicle design to address this but typically it is only during a major model redesign rather than between model years.

The popular solution, that is almost free, is simply moving the catalytic converter from mid-tailpipe to directly connected to the engine block. Essentially the CC is surrounded by the engine block itself on all sides, and you have to disassemble the entire engine from above to get to it.

But you're talking about 4~ years between redesigns and that doesn't address any of the vehicles already sold/tens of years of old designs.

I believe that the increased heat level closer to the engine would alter the CC's performance characteristics.

[1] - https://www.open.edu/openlearn/science-maths-technology/scie...

Alter: Improve.

Catalytic converters must be hot to operate effectively.

Improve the performance but reduce the lifespan.

People buy at a price point. Adding those panels adds cost. You’d have to give something up to get those panels.

Luxury cars have had these panels for a long time because they’re built to a higher price point.

Yep. Just keeping dirt and water out goes a long way for parts longevity, too.

And helps dramatically with soundproofing.

The problem will go away over time as we migrate to electric cars.

Perhaps a new problem -- that of stealing the more valuable batteries, might emerge?

That's approximately the same sort of operation as stealing the engine of a car. Not something you can do in a couple minutes with a battery powered angle grinder.

Tesla has demonstrated that their batteries can be removed and replaced in a matter of a minute or two, given the right equipment.

https://www.tesla.com/videos/battery-swap-event

Since the batteries cost an order of magnitude more than a catalytic converter, this could justify criminals developing more sophisticated equipment to pull it off.

This used to be more true, but with their new battery packs becoming an integral part of the frame, this is no longer going to be possible.

https://electrek.co/2021/01/19/tesla-structural-battery-pack...

Interesting, I’ve always thought it would make more sense to optimize for hot-swappable batteries rather than try to improve supercharger tech.

Four bricks and a jack I guess.

You know why I haven’t replaced the batteries on our 11 year old Nissan Leaf? Because I’m not quite ready to devote what will probably be multiple weekends to the job. So dispel any ideas you might have of someone snagging a battery pack in the middle of the night before I manage to release the hounds.

The battery packs will likely be serial number locked to the car as well as physically locked.

Internally they might just be standard cells. Might even be more profitable to sell them individually, just like shucking hard drives.

Somehow the big vendors get prices that consumers can only dream of.

EV batteries are even more valuable than catalytic converters. Even at 200 or 300 lbs per battery pack, I bet we'll see EV battery thefts in the next couple of years.

The Tesla Model 3 LR battery weighs 1060 pounds and can only be removed from the car as a single unit.

I’m sure we’ll see some thefts but these are easily removed and small. Most EV batteries are the opposite on both counts — and if they were designed to be removable, they’d fit them with locks like on e-bikes.

It’s easy to run a sting operation jailing any business which will buy battery packs with the locks cut off.

I recently bought a new Prius. Toyota even has bolt holes to allow easy installation of a "cat shield", and could install a nice steel plate there with minimal additional cost, but instead it was on me to buy and install an aftermarket product. Maybe it's a question of liability?

My hypothesis is that when you’re selling a product to a price-sensitive customer you have to strip down things.

This isn't a problem for about 90% of the population in the US. At best, Toyota would offer it as an option.

The shield would affect price, weight and mileage.

Then where would the catalytic converter dump the heat? Those things are dangerously hot and need cooling.

The engine dumps heat to the radiator and the exhaust. I think the catalyst does enable exothermic reactions, but it’s not using power, so it can’t get hotter than the outgoing exhaust (although that is pretty toasty). A computer adjusts the fuel/air ratio and timing to keep the incoming temperature and oxygen level in the catalyst’s effective range.

Some models even have a heater to get the catalyst working quickly after a cold start.

Automakers resisted putting backup cameras in cars and they provide the driver utility. A panel under the car adds no immediate utility to the buyer and therefore the extra $200 or whatever it would cost would detract buyers.

Manufacturers have been slowly adding plastic panels for aerodynamics under cars over the past couple of decades. Many new cars have just about everything covered other than areas that get too hot, like the exhaust.

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