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by steve_musk 2456 days ago
Sure if you’re driving only on the highway. What about driving around the city at 5-20 mph? Tesla’s end goal is to have autopilot do everything, so if they are serious about it then it makes sense to consider the impact at non-highway speeds.

Let’s say you are driving at an average speed of 20 mph - then by your estimate you’re using ~4666 watts. So if your chip is 500W it’s a significant portion of the power budget.
1 comments
dragontamer 2456 days ago
> What about driving around the city

Autopilot is highway only for now. I'd expect the chip to be off, at least with the current version, if you are on city roads.

But sure, if you're driving on city roads, lets really math it out. You have 70kW-hrs and maybe you're going 20 mph. Lets call that 4600 Watts of energy usage. Lets say you have a 500-Watt computer, for a total of 5100 Watts.

You can run your car for literally 13-hours at that power-usage. 70 kW-hrs is a lot of energy storage. A 4600 Watt power-usage results in ~15 hours of runtime instead.

Not a big change. And these are estimates only, I don't actually know what the energy-consumption metrics are for city vs highway. But these "poor calculations" are still good enough to realize that even a 500W computer is well within the power-budget of a 70,000 Watt-hr battery pack.

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Absolute worst case scenario (for the computer): you are going 0 MPH. Parked in a parking lot using only the computer. That means 100% of the power usage goes into the computer. What happens with a 500W computer?

Well, 70 kW-hrs can last 140 hrs at 500Ws of usage, that's over a workweek: over 5 days of computer usage. Are we seriously worried about the miniscule power usage of the car's computer system when a 70 kW-hr battery is in the car?

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pests 2456 days ago
Highway only? My roommate has one, I don't think he's ever not using autopilot even on side streets. He might only use the brake or accelerator a few times in a whole days driving.
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dragontamer 2456 days ago
> Traffic-Aware Cruise Control is primarily intended for driving on dry, straight roads,such as highways and freeways. It should not be used on city streets.

> Warning: Autosteer is intended for use only on highways and limited-access roads with a fully attentive driver. ... Do not use Autosteer on city streets, in construction zones, or in areas where bicyclists or pedestrians may be present.

https://www.tesla.com/sites/default/files/model_s_owners_man...

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pests 2456 days ago
I agree it says not to, but I also eat raw cookie dough and Im sure others do too
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lathiat 2456 days ago
Also this chip is SPECIFICALLY for FSD. Though true that current autopilot is not designed for city streets the "FSD Chip" / Telstra Computer is quite literally designed for slow city driving. And Elon specifically called out the power usage in these low speed scenarios.

Also even on the highway you're not using a lot of power in bumper-to-bumper traffic.

They also apparently had a power supply limitation in the older cars for retrofit.

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