Tesla originally planned to run two production lines but had to drop to a single one, and they're doing it in an expensive and unusual manner, and a second won't fit in their fremont plant, and they still plan to build out the second line in the same unusual 'cold' manner.

This leads me to expect it's reasonable their burn will continue at the same rate.

Furthermore, it's estimated they won't reach 3k a week till the end of 2018.

https://dailykanban.com/2017/10/source-tesla-responsible-mod...

I don't think any of the upfront investment or capital expenditure is included in the 1.4 billion calculation. Thats purely operating loss.

The $1.4bn is $300mn cash flows used in operating activities + $1.1bn capex.

So, can we assume that if the production has to be multiplied by 10, the cash flow used for operating activities should also be multiplied by almost 10, giving expenses of way more than $1.4bn?

No, because a huge cost for them right now is underutilization of assets (factory, tooling, some workers, etc.). Their utilization rate will improve, and so operating costs should not scale linearly with revenue growth. "Should" being the key word.

"Capital expenditures were $1.1 billion in Q3. The majority of capital expenditures were attributable to Model 3 and Gigafactory 1 production capacity increases. "

During the conference call, Musk himself said that CapEx in Q4 could be as high as in Q3.

much of those expenses are one-time cap ex