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Comment by Swizec | Hacker News Reader

At 10 gallons per minute, that's still just 2 minutes pumping time. (23 gallons)

Edit: I checked again, he pumps for 2.5 minutes and gets exactly 23 gallons. So I guess the pump isn't as fast as Elon says on stage. But it still surprised me because, well, that's about twice as long as what I'm used to :)

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This is a ridiculous discussion.

It takes about 3-5 minutes to fill up a large-tank performance car, similar in features and trim to the Model S. It takes about 2-4 minutes to fill up a smaller car. It takes less than 2 minutes to "fill up" a Model S.

It takes about 10 minutes if you also use the restroom. Are we going to start factoring that into the comparison? If not, I'm out.

Well it does seem that most of the time saved when filling up the Model S comes from not having to get out of the car in the first place. And I guess the credit card gets used from within the car?

They have your serial number. I'm sure it's just billed directly to your card on file.

What's probably most relevant is that it would take roughly as long to half-fill the Audi as to replace the Tesla's battery. That's in many ways a fairer comparison, as the Model S has roughly half the driving range of an Audi, and (I think) most car gasoline fill-ups aren't from near-empty back to full.

The model he fills up looks to be an A8. The A8 fuel economy is around 15-18MPG. So 20 gallon tank only gets 350 mile range on it.

Ok. That's a very guzzly car then, though; even other Audis like the A5 seem to do a lot better than that, especially on the highway.

Tesla's competition, from the perspective of performance and price, is very guzzly cars.

But big $100,000 cars like this mid-range S-class Merc http://www.mbusa.com/mercedes/vehicles/model/class-S/model-S... seem to have 20+ gallon gas tanks (here's the S550's capacity http://autos.yahoo.com/mercedes-benz/s-class/2013/s550/speci... ) and the ability to manage about 25MPG on the highway. That would place them at 500+ miles from a single fill. (They'll do a lot worse with city driving though: the S550 should only give 350 miles. I think these MPG numbers are the EPA's.)

Aside from the top end A8s with upgraded engines, they get 18MPG city and 28MPG highway. Simply saying that the A8 gets 15-18MPG is deceptive. So, if we are talking range, an A8 will get upwards of 560 miles on a tank.

If you're comparing on performance alone, you better get the upgraded Audi to match the Model S...

Did you watch the video? Not all of the time at the gas station is spent pumping.

Pumps vary dramatically in speed. My car has a 15.8 gallon tank, and it can easily take a couple of minutes to fill up (in Virginia).

Not to mention random pumps that you can never get to pump at full speed because they seem to fail to detect that the nozzle is in your tank's hole, or that click and stop every 3 seconds because the gas backs up because it doesn't flow down the tube fast enough.

As Musk points out, this is the fastest pump they could find in their area. Pumps vary tremendously in speed. Actually I'm curious about why the same pumps are sometimes fast, and sometimes very slow. Anybody know? Does tank level really matter that much?

Haha, well if Musk says so it must be true!

In the US, fuel pumps meant for regular sized cars (not trucks, boats, planes, etc) are limited to 10 gallons/minute. If that pump really was that fast, then it really was (among) the fastest legal pump(s) in the area.

http://www.epa.gov/otaq/regs/ld-hwy/evap/spitback.txt

I think it has to do with how much fuel is in the gas stations storage tanks. When the tanks get low they pump more slowly. I think it has to do with the pressure created by the weight of fuel pushing gas out of the bottom of the tank faster, there is more potential energy to push the gas faster in a full tank, mass x gravity x height equals potential energy.

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