ALT-2 Understanding Fuel Economy
Good fuel economy is really a very simple byproduct of vehicle efficiency.Vehicle efficiency is acquired by maintaining the car or trucks entire driveline, from the air intake to the tires.In writing this article I wanted to convey my approach to gaining good fuel efficiency;Thus I have decided to cover the top ten basic ways to improve your fuel economy.I put them in order of smallest to greatest impact upon fuel economy, and from number ten [least], to number one [greatest].#10- Oils, Additives, and Gadgets: Generally, only some of the gadgets available actually work.The "Tornado" is one that does work. However, the greatest fuel savings are mostly on older, pre-fuel injected vehicles.Fuel injected autos only see about a ten percent increase whereas carburetor vehicles see about a thirty to fifty percent increase.Oils are only important to the extent that you use the right kind of oil {10w-30, etc.], and that you use a high-quality motor oil such as Valvoline, Penzoil, Castrol or Mobile.I would dissuade you from using Texaco Havoline or any of the cheaper brands, as most of these are graphite-based and considered inferior. Not to be forgotten is that a small increase can be seen by using synthetic oils not only for the engine but for the transmission and rear differential as well.Additives such as Slick 50, EngineRestore and Lucas oil products are highly recommended. They help conserve fuel and also help your engine/trans/rear live longer.#9- Tire Pressure: Although often mentioned, it seems most people ignore their tire pressure.Correct tire pressure is good for safety as well as fuel economy, and it is the easiest and least expensive way to save fuel.#8- Gas brands and Types: This is also an important point: buying cheap gas is like buying cheap wine-you get what you pay for.Quality fuels like Texaco, Shell, and Mobil are "detergent-fuels"; meaning they contain the same additives and cleaners found in auto-parts stores' fuel cleaners/additives.Cheap gas is without these and usually of lower grade-don't buy it.Gas types-87 octane,89 octane and 92/93 octane fuels are graded according to their score.Most small and medium-sized cars/trucks use 87, while 89 and 92/93 are used by larger trucks and high performance autos, respectively.One thing I have noticed is that if you are someone who travels at high speed or towing a load, it is better to use 89 or even 92/93.This is a fact I learned during stints as a courier and whenever I had to tow something.#7- Air, Fuel, and Oil Filters: Your autos' various filters are to ensure that foreign objects don't enter and damage your engine.Periodically these filters become clogged, and when they do fuel economy goes way down. I have owned cars and trucks that wouldn't even start if the fuel filter became clogged. You should change these filters as recommended and not procrastinate.#6- Exhaust System: If your car already has a good exhaust, skip this one. If your in the market, get a high-performance cat-back exhaust and you will see gains in power and economy.#5- Vacuum System: This one is mostly for cars made between the mid-sixties to the late nineties. Cars during this period used engine vacuum to control various devices that opened or closed certain valves, etc. Basically, an internal-combustion engine is an air pump. It uses internal explosions to create rotational power; these explosions are made by forcing fuel and air into a piston chamber where this mixture is compressed and then ignited by the spark plug-resulting in the explosion.A byproduct of all this is that the pistons create a sucking [negative pressure] and blowing [positive pressure] effect. Air is sucked into the engine when each piston travels to the bottom of it's respective cylinder.After firing air is forced out into the exhaust system. It's basically like your vacuum cleaner; air is sucked in, filtered and sent back out. Now, imagine that the end of your vacuum hose had small holes in it. It wouldn't perform as well because there would be a loss of suction power.This is exactly what happens if you have any leaks in your vacuum system. Your car's fuel system is setup so that a certain amount of fuel is mixed with a certain amount of air. Any deviation from what is the ideal mix is bad- a rich fuel/air ratio results in fuel waste, while a lean ratio results in a loss of power.You create a lean fuel/air mix when there is any leak in the vacuum system. This results in your engine [computer-controlled], or your foot, sending more fuel to compensate because the engine is getting more air than it is supposed to.In short, check all vacuum lines and make sure they are not disconnected or cracked.#4- Ignition System: Your car's ignition system delivers voltage in the form of small sparks to fire the fuel/air mix. If any component is faulty the system won't work properly and the fuel/air mixture won't burn completely; resulting in a loss of power and economy. Change your spark plugs, wires and other components as recommended.#3- Emissions System: This one can be very complex and is required on all newer cars. Most emissions systems are powered by vacuum motors/valves, electronic solenoids, and/or the engine itself.Any malfunction in the emissions system sends a signal to the engine, usually telling it to go into either a closed or open loop setting. All modern, computer-controlled cars are in either of these modes during initial start-up [cold-start]. This means that when the engine is cold the computer dumps additional fuel/air into the engine to ensure a quick start-up for better fuel economy and lower emissions.When the emissions equipment fails it usually results in the computer telling the engine to go into start-up mode; thus your car will use a much greater amount of fuel and a black smoke will come out the exhaust.#2- Fuel System: The fuel delivery system, from the gas tank to the carb/injectors, should be air-tight and clean. If you notice any gas smell around or inside the car you have a fuel/fuel-vapor leak. This obviously wastes alot of gasoline, so check it out.#1- You, the Driver: Your personal driving habits have the greatest impact on your fuel economy. Try using less gas by initially accelerating at a good clip until you hit second gear, then let up some until you reach about 40-45 mph.At this point your overdrive or final gear should engage.I say this because initially you need to get your cars weight moving forward so that it is easier on the engine. This is what first gear is made for-to provide max torque in order to get it moving. I advise accelerating at a moderate to fast pace so that your car will get into overdrive quicker-resulting in better fuel economy.To end this article I would like to say that I am by no means a Professional Mechanic. All of my experience has been gained from owning/repairing/maintaining mostly older vehicles including mustangs,trucks of various types, lots of different Japanese cars/trucks and various others. I would consider myself the quintessential Shade Tree Mechanic.
