Better Gas Mileage
The best way to use less fuel is to park your car, but short of that there are many things that can affect fuel economy. Besides getting a more economical car, they fall into two groups; The condition of the vehicle and driving habits.
Optimizing the Car
Keep the tires inflated to proper pressures. Under inflated tires create more drag and use more fuel.
Use your air conditioning only when necessary. When driving below 50 MPH, roll down the windows or open the air vents to keep your car comfortable on not-so-hot days. Above 50 MPH it is just as economical to use the A/C because of the drag of an open window. Many vehicles will run the air conditioning in the defrost mode. If you don't need defrost, put the controls in heat or vent to reduce engine load and improve mileage.
Replace the engine's thermostat every 4-5 years. Thermostats tend to lose efficiency as they wear and will start opening too soon, not allowing the engine to reach the normal operating temperature. On-board computers won't put the engine into optimum economy operation until normal operating temperature is reached.. Most car engines are designed to run at 195 - 220 degrees and will not run as efficiently until it is reached.
Use Synthetic Oil. Synthetic oil creates less drag when the engine is cold and there is less engine friction all of the time, which can increase mileage by as much as 15%. Also the use of a fully synthetic oil results in less fossil based oil being consumed for lubrication.
Use quality fuel. Newer cars have the ability to adjust to lower quality fuels to a certain degree to prevent pinging or knocking. This is accomplished by not advancing the ignition timing as much, which leads to poor mileage. The money you save on the fuel may disappear from lower mileage and performance.
Keep the vehicle in good running condition. As spark plugs wear and filters get dirty, mileage slowly decreases. Follow recommend change intervals for spark plugs. Old cars need periodic adjustments, newer computer controlled cars need their systems tested anytime the check engine light is on or performance changes.
Optimizing the Driver
Go easy on the brakes and gas pedal. Avoid "jackrabbit" starts by accelerating gradually whenever possible. Heavy acceleration puts the fuel system into a high enrichment mode and uses much more fuel.
Anticipate stops to avoid sudden braking. When approaching a red light or stop sign, let off the gas and use deceleration as soon as you know you will need to stop. Most cars shut off fuel delivery to the engine under deceleration conditions to reduce emissions and save fuel.
Avoid prolong idling. Turn off the engine if you anticipate a lengthy wait. Instead of idling at a drive-up window, park the car and go in. Idling burns more gas than restarting the engine.
Limit car warm-ups in winter; your vehicle is designed to start driving after a 10-second warm-up if it is running properly. Avoid freeway speeds for the first couple of miles if possible.
Avoid tailgating. The car in front of you will keep you switching from the brake and gas pedals instead of using light throttle and deceleration for control. Braking wastes fuel used to regain desired speed.
Use overdrive and Cruise Control. Overdrive gears reduce both fuel consumption and engine wear. Also, using cruise control on highway trips helps maintain a constant, steady speed rather then a variable speed and as a result helps reduce fuel consumption.
Avoid higher Speeds. According to the EPA, gas mileage for most cars decreases rapidly at speeds above 60 miles per hour. For every 5 mph you drive over 60 mph, it's like paying an additional 24 cents per gallon for gas! That can really add up, especially on long trips.
Avoid carrying unneeded items in the trunk. Extra weight decreases gas mileage. Place items inside the car or trunk rather than on roof racks to reduce wind drag.
Don't go across town just for cheaper gas, driving 5 miles out of your way (10 miles round trip) to save 10 cents a gallon can cost an average of 45 cents more for that fill-up. And that doesn't count idling while waiting in line!
Whenever gas prices rise we see an increase in those Gas saving gadgets flooding the market. Most of them are the same things in a new package; a unit that gives off ultra sonic frequencies to the fuel, fuel atomizers in the PCV hose, magnets, intake vortex, etc.
Popular Mechanics conducted tests on 7 of the most popular devices at the Universal Technical Institute in Houston, Texas. Here are some of the results:
Four full-size pickup trucks were chosen for the tests. They strapped the trucks down to chassis dynamometers and ran them dry of gasoline. A measured quantity of gas was added and then they ran four dyno pulls to determine horsepower and torque. Next, they set the cruise control to 70 mph, to keep the speeds consistent and ran the trucks dry again. Then they put the same measure of gas in the trucks, installed the gas-savers and repeated the tests.
The inexpensive ones produced no change, but the more expensive ones reduced horsepower and mileage by differing percentages. One even caught fire during the tests.
Fuel combustion today typically exceeds 97 percent, that means 97% or more is used in the combustion process and not wasted. The problem is our engines aren't very efficient - only 20 to 35 percent of the fuel energy is converted to useful work - that's mostly due to heat loss (through the engine block, out the exhaust pipe) and unavoidable energy loss during burning itself.
High mileage is never the result of a single miraculous component, it's accomplished through electronics, new engine designs, lightweight materials, low-friction tires, improved aerodynamics, "ultra-lean-burn" engines, continuously variable transmissions or hybrid technology.Automobile manufactures are required to meet certain mileage quotas, it costs them if they don't. Teams of engineers spend years designing everything to work for the best possible mileage on each engine platform. You can sometimes increase performance by moving something from stock, but changes to really increase mileage is unlikely unless you are prepared to spend thousands of dollars. Keep the car in good operating condition, use synthetic oils and good driving habits is the best way to keep mileage up.