efficinecy

I was looking to add a spoiler to my 3, and I was looking on Ali express(ikr lol), and it claimed that it actually increases efficiency of the car by about 1 to 10 percent. Is this true? because I always thought adding a spoiler would make your car less efficient, and if it does make it less...

I used to remember closely following tractor trailer trucks to maximize fuel economy back in the ICE days, and a though occurred to me that with the right software tweaks, our Tesla Model S/X autopilot be can really good at this. It was reported that by closely following a truck, one can save...