Last week we received and installed the new Tesla Model 3 Roof Rack on our car – go check out the install if you are curious. One of the comments I have been receiving and seeing online in the forums is “how does the roof rack affect your efficiency?” I decided to do a controlled test to find out!
I created a test plan to help ensure I had control over as many elements as I could during the testing. Since I already had the roof rack and Yakima ski box installed, Test #1 started there! Check out the video below to see how we conducted the test, and my random thoughts that popped up during the testing process.
Now that you’ve watched the video or read the test plan, you understand how we controlled the test. The results are tabulated below – bear in mind that I have winter tires on and it is cold outside, so the bare roof consumption is likely higher than what you were probably expecting… but that doesn’t matter, as what I was interested in finding out is how the consumption is increased by adding the rack, then the ski box.
Looking at the consumption table for the downhill and uphill only segments – you’ll see that the difference in consumption is essentially the same as the overall difference in consumption presented in the second table. So I think I was successful at removing the element of differences in elevation from the equation. The only thing I didn’t control for that might have had some effect on the testing is whether that battery has different internal resistance at different states of charge – I don’t think it does, but if you happen to know, chime in with a comment below!
So given the approximate error in the measurement/calculations, it appears that the difference of installing the rack is negligible – a few % at worst. Adding the ski box however, that increased consumption on the order of 10 – 15%. I’m going to use 15% in my future trip planning when I use A Better Route Planner.
But now for some context! Sure I’m increasing the consumption on my Model 3 when I install the roof rack plus ski box, but what is my alternative? Well in my case, I came from a Subaru Forester, and while it has more cargo room than the Model 3, it still doesn’t fit skis inside the car any better than the Model 3 (actually it is worse, as the Model 3 has a longer “load floor”, so fits our XC skis better), so I had the ski box installed on that car anyways! So let’s compare consumption for the Subaru vs the Model 3:
I think the overall net benefit here is pretty clear! Five times more energy to move a similar sized vehicle, similar weight vehicle, with the same number of occupants and their ski gear… the Model 3 clearly wins here, even with the roof rack installed! The amount of extra energy needed to move the Forester is just atrocious. Even compared against a Prius (arguably the mainstream pinnacle of ICE efficiency), which at best has an average consumption of about 1/2 of the Subaru would still yield the Model 3 being 2.5x more efficient than the Prius!
If this content has swayed you to buy a Tesla, please consider using my store referral link to order: https://ts.la/andrew71174, or give the code “andrew71174” to your Sales Advisor during your purchase. Generally you will get some kind of benefit.