lorenfb wrote:While traveling on freeways (50% of driving) at 60 - 65 MPH in the past, my overall average was about 4.5 miles/kWh.
Presently, my freeway speeds are 50 - 52 MPH. My overall average is now 5.1 miles/kWh. That's about a 13% improvement
without any aero mods, and how simple was that!
Yes! The easiest "aeromod" is to simply reduce speed. If you drive at 12mph you'll be able to go very far.
But let's say you could reduce the aerodynamic drag to a coefficient of around 0.17Cd. The result would be that going 65mph you'd get the efficiency of going 45mph without aeromods.
With aeromods you also benefit if you use climate control because going faster you would use the climate control for less time.
The only thing I see in this thread, though, is that everyone seems to go about aeromodding backwards. The focus usually goes towards the front of the vehicle. Not that there isn't room for improvement in the front, but the main improvements to be made are in the rear of a vehicle.
As you can see, the distinctive tear drop shape can have a barely noticeable 0.05Cd going forwards or a terrible 0.34Cd going backwards. That's nearly 8 times the amount of air drag!
The few times I've seen cars put in a wind tunnel backwards, that's almost always when they are more aerodynamic. The Leaf is similar in design to other cars. The sloping part is in the front, and the blunt end is in the rear. Aerodynamically it should be the other way around. But we aren't going to be going down the highway backwards now are we. Others have overcome this by simply adding and airplane or boat tail to the rear of the vehicle. A classic example is the AeroCivic, which cut it's drag in half, and the biggest improvement wasn't the wheel spats or blocking off the front grill. It was the tail that was attached to it.
AeroCivic wrote:The biggest one, both in strange looks received and on its effect in improving my gas mileage is the boat tail. This is the tapered back end of my car that resembles the back of an aircraft fuselage. This eliminates the recirculating, low-pressure eddy that forms behind "normal" cars and that act to slow them down. This eddy is also responsible for the dirt that accumulates on a car's backside and allows a closely following car to improve its mileage by drafting. As a result of my boat tail, the back end of my car remains clean and anybody drafting me would gain no mileage benefits.