Whether you're driving on the open road or stuck in traffic downtown, you expect your car to perform when you put your foot on the gas pedal. If you think your car's performance relies on its manufacturer and your maintaining the vehicle, you're right. But it also depends on the quality of gasoline you put in it. If you put a lower-quality gasoline, with a less effective additive, you could pay the price.
Your engine could have trouble starting when cold, might warm up slowly, and might not run smoothly under some conditions.
You might not receive the power you expect.
Over time, fuel economy could suffer, and your car could generate more emissions into the atmosphere.
Your choice of gasoline could add to engine deposits on critical engine parts.
Engine Deposits and Performance
Although proper vehicle design and maintenance are necessary, gasoline plays an important role in meeting these expectations. However, since almost all base gasolines are formulated to the same regulated specifications, the performance of the deposit-control additive is one of the most important features that differentiates one brand of gasoline from another.
Almost without exception, harmful deposits would build up inside your engine if commercial gasolines did not contain effective deposit-control additives. The best of today's additives not only can keep engines clean, they also can remove existing deposits to help restore the original performance designed into the engine.
Most automotive gasoline engines operate in a four-stroke cycle: intake, compression, power and exhaust. The first downward motion of the piston in the four-stroke cycle—the intake stroke—draws the air-fuel mixture into the combustion chamber through the open intake valves. As the piston reverses direction and begins to move back up, the intake valves close. This upward motion of the piston is the compression stroke. Compression raises the pressure and temperature of the mixture, causing it to vaporize. Near the top of the compression stroke, the spark plug produces a spark, igniting the fuel vapors. The mixture burns and expands, which drives the piston downward for the third stroke, or power stroke. As the piston reaches the bottom of its movement and begins to move back up again, the exhaust valves open, beginning the exhaust stroke. The upward motion of the piston pushes the burned gases out of the engine into the exhaust manifold and eventually out the exhaust pipe. See a demonstration in Flash of how your engine works, and how fuels with the Techron additive help keep it clean.
Fuel Injectors and Carburetors
Fuel injectors are designed to accurately meter fuel to the engine and to deliver it in a precise pattern of fine droplets. Because the fuel passages are small, injectors are highly sensitive to small amounts of deposits in the critical regions where the fuel is metered and atomized. These deposits can reduce fuel flow and alter the spray pattern, degrading drivability, decreasing power and fuel economy, and increasing exhaust emissions. Deposits cause similar problems for carbureted engines because carburetors also use a number of small channels and orifices to meter fuel.
Volatility, or the fuel's tendency to vaporize, is the key gasoline characteristic for good vehicle drivability. Drivability describes how your vehicle starts, warms up, runs and performs to your expectations. When the spray pattern of your fuel from the fuel injector is disrupted, the vaporization of the fuel can be negatively affected. That can seriously impact your car's drivability because only fuel vapor actually burns; solids and liquids don't burn at all.
Intake Valves and Ports
Deposits form on intake valves and ports because they operate at high temperatures in a very reactive environment whenever the engine is running. If the deposits become heavy, they reduce engine power because they restrict and alter the flow of air and fuel into and within the cylinder. In some sensitive fuel-injected engines, even low levels of intake valve deposits can hurt performance. Cold-start and warm-up drivability can be adversely affected and exhaust emissions increase. The magnitude of the emissions increase can be surprisingly large. This occurs because the deposits act somewhat like a sponge, absorbing and then releasing fuel, which upsets the ratio of fuel and air, particularly as the engine is changing speed. Other valve deposit problems include valve sticking—because deposits interfere with the valve stem sliding in its guide, and burned valves-because severe deposits prevent the valve from seating properly.
Combustion Chamber
A brand new engine requires an octane level determined by its design and the quality of its manufacturer. The engine's octane number requirement (ONR) increases as combustion chamber deposits form during the first several thousand miles of operation. If the increase is large enough, the engine manufacturer's recommended octane level may no longer prevent knocking. If the vehicle is equipped with a knock sensor, it may experience a loss of power.
Research has shown that precursors for combustion chamber deposits come from the fuel, some fuel additives and the engine oil, and that certain fuel and engine oil components form more deposits than others.
Combustion chamber deposit interference (CCDI) and combustion chamber deposit flaking (CCDF) are two other problems which sometimes occur in certain modern engine designs. CCDI is the result of physical contact between deposits on the piston top and cylinder head and is manifested as a loud, metallic banging sound when the engine is cold. CCDI is limited to the engines that have been designed primarily to reduce emissions, with minimal clearance—one millimeter or less—between some areas of the piston top and the cylinder head (squish areas) when the piston is at top dead center. Combustion chamber deposit flaking causes low-compression pressures to result due to improper sealing of the valves. This problem occurs when pieces of CCD flake off and end up lodged between the valve face and the valve seat. Typical symptoms of CCDF are difficulty in starting and rough running when cold.
About half of the cars and trucks on the road today have engines that are equipped with a device called a knock sensor. A knock sensor is designed to detect knock, often before the driver does. Upon sensing knocking or pinging, the engine's computer control system (engine control module or ECM) adjusts the engine's operation (retards the spark timing) to avoid the knock. These adjustments can reduce power and acceleration under certain driving conditions, especially under heavy acceleration when you want power the most.
Since excessive combustion chamber deposits can promote knock, they can also suppress your engine's full potential by contributing to more frequent knock-sensor operation. Texaco and Chevron gasolines with Techron are unbeatable at preventing harmful combustion chamber deposits, helping your engine maintain the maximum performance for which it was designed.
Lower Emissions
Modern engines are designed to run their best when vital engine parts are kept clean. Fuel injector deposits can cause hesitation and stumbling on acceleration, lower fuel economy, reduced power output, and increased emissions of hydrocarbons and carbon monoxide. Excessive intake valve deposits can cause many of the same performance problems, plus higher emissions of nitrogen oxides.
The EPA requires that all gasolines sold contain a deposit control additive. There are a number of different deposit control additives that can be used, and most do an adequate job in the engine's intake system. However, many additives contribute to combustion chamber deposits. Excessive combustion chamber deposits can cause an engine to need higher octane fuel to avoid knock, run-on or reduced engine performance. These excessive deposits can also cause increased emissions of nitrogen oxides. In contrast, Techron provides unbeatable intake system performance and minimizes contributing to harmful combustion chamber deposits.
