Excellent Autoline Afterhours

Bob Wilson

 

At 111,720 miles, my Tesla is long since beyond the warranty which makes me happy. I can do anything I want and not risk losing the nonexistent warranty. For example, the after market wheels:


So after reading: The Effects of Wheel Design on the Aerodynamic Drag of Passenger Vehicles

Approximately 25 % of a passenger vehicle’s aerodynamic drag comes directly or indirectly from its wheels, indicating that the rim geometry is highly relevant for increasing the vehicle’s overall energy efficiency. An extensive experimental study is presented where a parametric model of the rim design was developed, and statistical methods were employed to isolate the aerodynamic effects of certain geometric rim parameters. In addition to wind tunnel force measurements, this study employed the flowfield measurement techniques of wake surveys, wheelhouse pressure measurements, and base pressure measurements to investigate and explain the most important parameters’ effects on the flowfield.​

So I'm making my own wheel covers based on the paper. Here is the prototype:

I'm working on the fittings to attach to the wheel.

Bob Wilson

 

I will but more as part of hunting down inefficiencies. For example, even though the vast majority of kinetic energy is captured by regenerative braking, there is a small part at very low speed that adds heat to the brake pads. A zone where typically there is very little airflow and not one I'm worried about. Regardless, it is fairly easy to add venting to the solid wheel cover. I am more concerned that blocked off, the pressure differential will 'blow the covers off' at speed.

There is normal 'resting' of the brake pads against the rotors. A fine anti-corrosion strategy, it is also a small drag force that can be reduced or even eliminated. Benchmarking will let us know how much.

Recently, it looks like turning the head lights off during the day may have a measurable effect on efficiency. I have not benchmarked it, yet.

I also plan to trim down a water noodle and with duct tape, reduce the area and shape of the air inlet. Again, it will be benchmarked along with measuring coolant temperature.

The outside mirrors are also on my list to be investigated.

Bob Wilson