There are several forums on the internet where serious individuals discuss the tricks and tweaks they use to get significantly higher gasoline mileage.</br>
When you realize that EV's will benefit in range by using several of their tricks, it becomes apparent that we can learn a lot from these forums.
Start with one of the range calculators for EV's, like:
http://evconvert.com/tools/evcalc/ Plug in the information about your EV or about your plans, and you will get some range estimates. The range estimates seem to be on target, if you drive conservatively.
It will also allow you to change some things like the effect of Low Rolling Resistance tires, tire size, and weight reduction. If you go a step farther, you will find that the aerodynamics of your car become increasingly important as you near highway speeds. Search the internet looking for aerodynamic improvements you can make for your vehicle.
I have an S-10, and it is quite sensitive to aerodynamic improvements, and sensitive to low rolling resistance tires, etc. While I was looking for ways to increase the range. Here are some of the items I found:
The starting placesLower the car – This has two benefits. With less tire and wheel showing, the frontal area is less. With less air going under the vehicle, the turbulence is less.
There will be an ideal ride height for each car. A ground hight of around 3 inches seems to be ideal. According to Mercedes, "Lowering the ride height at speed results in a 3-percent improvement in drag."
When removing gasoline tank and exhaust under the car, pay attention to how clean you can make the aerodynamics. A body pan is not that difficult to create, it is more labor intensive than cost intensive. Remember, the bottom surface of the car is almost as important aerodynamically as the top.
If
a body pan is too difficult or too expensive, an air dam add benefit. It will redirect air that will normally enter the turbulent underpanel of the car, and significantly decrease drag.
Covering the rear wheel wells, called “fairing.” This will dramatically reduce the turbulent air flow around the rear wheel opening. While the front wheel can not easily be completely faired due to clearances needed for turning, a partial fairing can be made. Any mud flaps, or mud flap like structures should be removed. Many of the newer cars have vestigial mud flaps to keep the body clean if the car is driven on a mud or dirt road, and these are integral to the body structure. While a good body shop can remove them, this is expensive. If they are bolt on, remove them.
Clean up the front of the car. Any large openings originally designed to allow air flow to cool the gasoline motor can be covered, and you should remember to cover them aerodynamically. If you can completely cover the opening, you can make a panel that is aerodynamic from plastic or composite.
Evaluate the side view mirrors. Consider smaller mirrors or instead use a remote camera system.
Replace large whip antennas with smaller powered antennas.
A small "tail cone" can be affixed the the rear bumper to help transition the air from under the car.
Side fairings can be used to clean up the lower half of the body between the tires. More...
Additional mods for trucks:If you need the utility of a truck, there are things that can be done to improve their efficiency. In addition to the items noted above, most notably, cover the bed! A flat hard cover will help some, but a custom aero cover is much more efficient. Experimentation has shown that simple removal of the truck tailgate does not provide better mileage.
Turbulators, etc:In areas where the body transitions at a rate of more than 12 degrees, turbulator strips, vortex generators, diffusers, very short fairings or other devices can be used to "trip the airflow".
The idea is that areas like the transition between the roof and rear window on the average car creates a large vortex. Any large vortices effectively grab the car and try to hold it back as it tries to slip through the air. If the air that makes up the vortex can be "tripped" before it leaves the back of the car, it will make smaller vortices, which will have a smaller effect on the overall aerodynamics of the vehicle. Measurement of the effects of these devices at highway speeds has been difficult to obtain.
Tires:Tire rolling resistance (RR) also plays a large part in the mileage of a vehicle. Running your tire pressure at higher pressures will help somewhat (do not exceed rated pressures printed on the side of the tire), but specially designed low RR tires will help more. The typical 20% reduction in RR from a low RR tire can result in energy savings of 2% to 10%. Here are some of the Low Rolling Resistance tires on the market, but be aware that some testers find that these tires do not handle as well as normal "sport" tires.
Some of the tires on the market are:
Maker Model Size Rolling Resistance Coefficient
Bridgestone B381 185/70R14 0.0062
Nokian NRT2 185/70R14 0.0085
Sumitomo HRT 200 185/70R14 0.0092
Dunlap Graspic DS1 185/70R14 0.0092
Dunlap Sp 40 A/S 185/70R14 0.0103
Bridgestone WS 50 Blizzak 185/70R14 0.0103
Goodyear Viva 2 185/70R14 0.0104
For comparison, we used identical tire sizes. Please consult your tire dealer for newer information in the size that is appropriate for your vehicle. Ask about the RRC (rolling resistance coefficient, your dealer should have this information.
Wheel covers:Unfortunately, the best way to make the surface of the wheel more aerodynamic is to use “moon hub caps,” which are a slightly convex, completely smooth cover that fits flush with the tire. Not “baby moons” but the full wheel disks which are quite aerodynamic. These are usually made of spun aluminum, or stainless steel, and can be easily dented. Some use 10-32 self tapping screws designed not to go through into the tire bead. Some use spread clips to fasten. The spread clip ones are a little more prone to coming off if the wheel hits a curb or a pothole, but they have no likelihood of causing air leaks. Wheel disks are a little hard to find, but are worth it.
Beaded seat covers as an alternative to air conditioning.. Last summer, with the over $4 gasoline, most local cabbies did not run the air conditioning, but almost all cabbies had a beaded seat cover. These give good air flow if you sit for a while in the seat. They don't make the car cold, but they do make a summer day more comfortable.
Other air conditioning alternatives:Open the windows if your speed is under 30 MPH. If you run over 30 MPH, your energy savings will be considerably improved by closing the windows and using the fan or dash vents.
Add a fan to the cabin, generally angled toward the driver's trunk. A cool breeze feels best in your face, but little objects like bugs or dust can
be picked up and sent toward your eyes.
The Radiator opening.The radiator opening in the gasoline engine car was needed to send air through the radiator to cool the gasoline engine. This opening will continue to gulp air in, forcing the air into a turbulent flow through the front compartment. Blocking off all or most of the front compartment opening is essential. Unfortunately, the easiest way to block the opening is with a flat panel. This is also inefficient, as the aerodynamics of a brick are poor. But covering the opening with a lightweight structure with a bullet nose produces a better way to break through the air. Starting with half round gutters from your favorite home store will be a better alternative. If the nose of your car is not flat, you may take the gutter material, and trim it to make a point in the material so that it more closely follows the contour of the body. You can add an inside miter cut at a few degrees of angle to cover the pointed nose of some designs. Gutters are available in aluminum or galvanized steel, either is suggested. Newer gutters are made of plastic, which is also suggested, but more difficult to find in the half round shape. Most plastics are very easy to cut and to join, so working in plastics is likely the best.
