Tech Tips - Engine Oil Primer
ATVs and UTVs used for racing, trail riding, heavy hauling and nearly every other application share at least one trait: they pose significant challenges to the fluids that protect them. Despite spending thousands to purchase and modify their machines, some enthusiasts mistakenly see no reason for premium fluids when servicing their ATVs and UTVs. Synthetic motor oil, grease and other high-quality lubricants, however, are formulated to meet the challenges posed by ATVs and UTVs better than lower-cost conventional fluids.
1. Extreme Engine Stress
Premium synthetic motor oil is vital to maximizing engine performance and life. The churning action and pressure inside high-rpm ATV and UTV engines creates shearing forces that can literally tear apart, or shear, the molecular structure of inferior oils. As it is forced between tight clearances, such as the interfaces of the piston ring/cylinder wall and cam lobe/lifter, the oil can permanently lose viscosity. Oil that has sheared out of its intended viscosity range can fail to form a protective lubricating film on parts, leading to accelerated wear.
2. All-Season Performance
Adding to the challenge, engine oil must balance cold-weather fluidity with high-temperature protection. That’s why many ATVs and UTVs require oils with a broad viscosity rating (e.g. 0W-40). Lower “W” numbers indicate the oil flows more readily at colder temperatures, improving cold starts and allowing the oil to circulate quickly for fast engine protection. The second number indicates the oil’s viscosity at operating temperature. Higher numbers indicate the oil remains thicker. Because increased viscosity relates to the oil’s ability to bear load, one might assume the higher the viscosity at operating temperature, the better. Not necessarily. Using oil with an unnecessarily high viscosity can increase fluid friction, which reduces fuel efficiency. It can also increase operating temperature, hastening oil oxidation and degradation. Finding the optimum balance is vital to all-season performance.
The advanced chemistry of synthetic motor oil provides performance conventional oils simply can’t match. Conventional oils contain wax, which causes it to thicken in cold weather. They also can boil off at high temperatures, leaving behind harmful engine deposits. Synthetics, on the other hand, do not contain wax. They offer improved resistance to high-temperature boil-off and viscosity loss due to shear, resulting in maximum wear protection and all-season protection and performance.
3. Ethanol Problems
Currently, most gasoline sold in the U.S. contains up to 10 percent ethanol (E10), and government agencies and lawmakers have authorized sale of gas containing 15 percent (E15). Ethanol is susceptible to water intrusion; when water collects in the gas tank through condensation or other means, the bond between ethanol and gasoline can break because ethanol is hygroscopic (it likes water more than it likes gasoline). This phenomenon is known as phase separation. The ethanol bonds with the water and sinks to the bottom of the fuel tank, which can create a whole host of problems, including the formation of gums, varnish and other insoluble debris that can plug fuel flow passages and negatively affect engine performance. When this ethanol/water mixture is pulled into the engine, it creates a lean-burn situation that increases combustion chamber temperatures and can lead to engine damage.
Treat gasoline stored in cans with a fuel additive specifically formulated to address ethanol-related problems, specifically phase separation. For best results, use an additive also formulated to clean combustion chamber, injector and carburetor deposits. Look for an additive containing the highest concentration of cleaning agents for maximum performance, and use it at each fill up for best performance. Try not to store fuel for more than a month. If you’ve got to store it much longer than that run it through your car or truck engine which has sophisticated engine management systems and knock sensors that can handle fuel with slight degradation. NEVER put any premix in your car or truck though. The premix oil will destroy your catalytic converter, costing you a slight fortune to replace.
4. Chaincase & Gearcase Protection
To reduce costs, some enthusiasts use automatic transmission fluid (ATF) or gear lube in their chaincases and gearcases. Neither fluid, however, is engineered for these applications. ATF is a hydraulic fluid formulated without the extreme-pressure additives needed to provide enhanced wear protection, leaving gears and chains vulnerable to premature failure. Automotive gear lube is designed to lubricate hypoid gears and is generally too thick for proper chain and gear lubrication, impairing circulation and leading to wear and decreased energy efficiency. For maximum life and performance, use a high-quality synthetic chaincase and gearcase lube formulated with extreme-pressure additives to provide an extra measure of wear protection. Other important performance features include the ability to repel water, and resist foam and corrosion.
5. Water Washout & Increased Heat
For suspension and steering components exposed to water and mud, use grease specifically formulated with high adhesion and cohesion properties to resist water washout and remain in place. Racing ATVs exposed to high heat and friction should be serviced using synthetic racing grease formulated for maximum friction-reduction and high-temperature performance.
6. Use quality filters and Oil
Think of your air and oil filters as the last line of defense keeping the grit on the outside of your engine from wreaking havoc on the inside. ALWAYS use quality air and oil filters, and change them at least as often as the maintenance schedule suggests. Service more often if you pull a heavy load or ride in extremely dusty or muddy conditions. Should water enter your engine it’s important to thoroughly drain it out as soon as possible. If the oil looks chalky, or like dirty chocolate milk it’s still contaminated with water and must be drained again. Good quality oil, oil filters, and air filters are always much cheaper than buying engine parts.
Following these simple, yet effective, guidelines when performing maintenance can help you get the best performance and most years out of your ATV or UTV.
John Baker is a technical writer for AMSOIL INC., a leader in synthetic lubrication since developing the world’s first API-certified synthetic motor oil for automobiles in 1972.