So movement in oil primarily impacts stock sentiment with very limited impact on the business itself. So this can be seen as a frustration or opportunity for investors. The opportunity is to buy the stock when sentiment is low.
An average ICE vehicle gets about 1000 miles per barrel and will be driven about 150,000 miles within its first 10 years. Thus the value of an ICE vehicle is short about 150 barrels. This gives us a handy way to track cages in the value of these vehicle relative to changes in oil. If the price of oil goes up $1 per barrel, then ICE vehicles lose about $150 in value. So the decline of oil from about $80/b to $30/b increases the value of ICE vehicles by $7500. Note that this is the size of the federal tax incentive for EVs. Thus, the decline in oil has merely nutralized the tax advantage that EVs enjoy in the US. Moreover if oil fell further to $20/b, this would only add a $1500 advantage to conventional vehicles. These impacts are huge if you are selling something as non-compelling as the Leaf, but I believe Tesla is offering products that are sufficiently compelling that a comparitive value shift of $7500 does not create a material demand shift. This is especially true for Models S and X, where $7500 is just 7.5% of the price of the car. The sensitivity for Model 3 will be higher as these are lower priced cars where $7500 is 15% of the price of the car. But here is where we have a huge timing advantage. Oil is presently low. Suppose it stays low through the first year of Model 3 deliveries. This satisfies the demand of early adopters so no problem. Then suppose that in 2019 oil climbs back up to $60 or $80 per barrel up from $30 at launch. This definitely fuels demand globally for the Model 3. Even without this boost I think demand scales nicely through 2020, but with this oil tailwind stock sentiment should get a huge boost as well. In any case, it is beneficial that the price of oil is low heading into the Model 3 launch.
So while I cannot predict how low oil will go, the incremental impact on demand is pretty minimal. If oil were to fall below $20/b, that could be a wonderful set up for the Model 3. In a few years, oil should be a huge tailwind for the stock.