A. Yes! Fuel additives are a great product for today’s drivers. Dirty fuel injectors continue to plague engines with multiport fuel injection, while dirty intake valves can be a problem with many gasoline direct injection systems.
Dirty injectors cause the air/fuel mixture to run lean, which can cause hesitation, lean misfire, loss of power and reduced fuel economy. The same thing can happen if the heads and stems of the intake valves become coated with carbon deposits.
EPA rules require gasoline retailers to include minimal levels of detergent in their fuels to help prevent the formation of fuel injector deposits and valve deposits. However, many experts feel the minimum levels in some gasolines do not provide adequate protection for many motorists. Some gasoline retailers (“Top Tier” suppliers) have upped their additive concentrations to help combat the problem, but even these may not be enough for many high mileage engines – especially if stubborn deposits have already accumulated in the injectors, valves and combustion chambers.
Aftermarket fuel additives that are specially formulated to (1) prevent deposit formation, (2) remove accumulated deposits or (3) do both functions can help improve fuel economy, performance and emissions. What’s important here is recommending the “right” product for the application. Study the labels on the products to see what type of injection systems and deposits the product is formulated to treat. Intake valve deposits on late-model engines with gasoline direct injection can be especially difficult to prevent and remove because fuel is sprayed directly into the combustion chamber rather than the intake port. Consequently, detergents and cleaners in the fuel do not come into direct contact with the backs of the intake valves. For these applications, an aerosol product that is sprayed into the intake manifold or directly into the intake ports (after removing the intake manifold) may be necessary to clean the valves. Always follow the usage directions on the label.
Q. Are oil additives needed in today’s engines?
A. Motor oils that meet current OEM and API oil performance standards do not require any supplemental additives – except in certain situations. Older engines with flat tappet cams and high performance engines do require oils fortified with additional ZDDP anti-wear additive, or a ZDDP supplement to prevent premature cam and lifter wear. The amount of ZDDP in current motor oils has been reduced by more than half to help prolong the life of catalytic converters. Most late-model engines have roller cams or overhead cams with roller followers so they do not require as much ZDDP anti-wear additive as the older engines.
Other crankcase additives can be beneficial to older high-mileage engines. These include products that are formulated to help reduce oil consumption due to advanced engine wear, and to help “rejuvenate” aging gaskets and seals to reduce oil leaks. There are also specially formulated “high mileage” oils that contain additional additives (seal conditioners) for the same purpose. Some additives also can reduce friction somewhat for better fuel economy and performance, but so can lower viscosity motor oils such as 0W-20, 0W-40 and 5W-20.