Dear Car Fix: My engine has some issues and the dealer told me I had bought bad gas. What is the real story? My friends told me it really was the ethanol in the gas. Can you explain it all? Thanks.
-- M.H., Silver Creek
Due to the large number of recent changes to fuel, numerous problems with gasoline-powered vehicles have developed. These problems are not always immediately identified as fuel problems, and therefore technicians are spending a lot of time and money on symptoms, rather than root causes. Most technicians will tell you they have seen a dramatic increase in the number of complaints of performance, poor fuel economy or check-engine light illumination due to the failure of exhaust-related emissions items (EGR, oxygen sensors, catalytic converters, etc.) in the last two years. Ask them the root cause and you will hear many theories. In order to properly understand what is happening, a little history review is helpful.
In the late 1980s emissions standards had become more stringent making fuel injection a necessity. These vehicles burned cleaner and ran better than carburetor-equipped vehicles. Drivability concerns began to developin the form of starting and stalling when cold, rough running and stumbling on acceleration. These were caused by the accumulation of soft carbon deposits in the engine. The higher operating temperatures and tighter clearances combined with the quality of fuel were the main contributing factors to these problems.
In the early 1990s the federal government established requirements for fuel additives to reduce the occurrence of these problems. All fuel sold in our country had a minimum amount of cleaner. One of the main additives was MTBE. It was very effective at keeping injectors clean and carbon growth to a minimum. In the mid-1990s more stringent emissions standards and on-board diagnostics (OBDII) were universally adopted on all vehicles. The amount of cleaner in the fuel was adequate in most applications to stay within emissions and maintain acceptable levels of drivability, until the price of crude oil began to rise dramatically shortly after 2000.
The federal government was keeping a close watch on the price of gasoline due to its impact on the economy. When the price of fuel rose above $3 per gallon, the government approached fuel manufacturers. With the threat of $5-per-gallon fuel, the regulations for the required amount of cleaners in fuel were lowered substantially. This did keep the price down, but drivability concerns began to slowly return. The root cause was the increased accumulation of deposits in the engine causing hard carbon to form. The OBDII system reacts to detonation (spark knock) faster than the ear can detect it. It electronically retards the timing until the detonation stops. This retarding of the ignition timing robs power and economy and creates more emissions in the exhaust stream.
Shortly after this first change, MTBE was found to be a cancer-causing agent. It was ordered out of fuel, yet cleaners were still needed. The most common replacement currently used is ethanol. Ethanol does have some cleaning qualities; however the negative side effects are staggering. It is a very strong product that attacks plastic. As most fuel systems have moved to plastic or epoxy-coated parts, this has caused severe problems. Fuel filters are becoming clogged, and the dissolved plastic forms deposits anywhere it can find a heat source from the fuel pump to the injectors. Once sprayed from the injectors, the deposits cause hard and soft carbon to form at an alarming rate. Severe deposit formations cause excessive ignition timing retardation and oil contamination with unburned or partially burned ethanol causing engine oil to emit phosphorous vapors into the PCV system, which are in turn pulled into the intake system and burned. These burned phosphorous vapors coat the sensing surfaces of the oxygen sensors and the reaction bed of the catalytic converter causing them to malfunction.
An additional problem with fuel today is ethanol absorbs water; even the humidity in the air will transfer into the fuel. This happens when fuel is stored in tanks at the fuel station. When the amount of water exceeds a certain amount, the ethanol and water "fall out" to the bottom of the tank. This is called phase separation. Phase-separated fuel confuses the engine management system causing decreases in performance and mileage. It also leads to premature failure of expensive components.
Standard fuel additives such as dry gas and fuel stabilizer have little effect and some even aggravate the problem. The only solution is a product call Fuel Fix by WellWorth Products. It keeps the ethanol blended and your drivability problems should be fixed.