FREQUENTLY ASKED QUESTIONS
2-Cycle Oils
No. Royal Purple’s 2-cycle oils are formulated for use in gasoline applications only.
HP 2-C® is recommended for most stock oil-injection applications.For cold weather oil-injection applications, Snow 2-C® is recommended.
HP 2-C may be used in pre-mix applications.
For low temperature, oil-injected applications, Royal Purple Snow 2-C is recommended.
Royal Purple HP 2-C meets the performance requirements of any 2-stroke gasoline engine; however it does not carry any OEM oil licenses.
Cooling System Additives
Purple Ice should not be used with other heat-transfer or cooling enhancing products or “water wetters”. If such a product has been used in the cooling system, the system should be drained and flushed with Royal Flush® before using Purple Ice.
Purple Ice is compatible with cooling system additives intended to stop or slow leaks. Please note that such stop-leak products often typically put a coating on the interior surfaces of the cooling system, so the effects of Purple Ice may be diminished.
Purple Ice is compatible with all current OEM/factory and major brand automotive anti-freeze. This includes traditional green ethylene glycols, as well as OAT/HOAT antifreezes (e.g. DexCool; Ford and Chrysler orange, gold, pink; European and Japanese OEM red, pink, etc.).
Purple Ice may be added to any antifreeze / water mix; however, testing has shown higher water concentrations yield greater cooling benefits. While Purple Ice does contain corrosion inhibitors as well as lubricants to compensate for a lower antifreeze / water concentration, Royal Purple recommends using a concentration of antifreeze appropriate for the cold winter temperatures in your area because Purple Ice offers no freeze or boiling protection. The preferred coolant mix would contain a minimum of 20% antifreeze (offers 12°F protection) to provide a higher boiling point, and greater corrosion and deposit protection for the coolant, along with 1 to 2 ounces of Purple Ice per quart of coolant.
When using Purple Ice with a 50/50 antifreeze/water mix, we recommend adding 1 ounce of Purple Ice per quart of cooling system capacity. For straight water (racing) or higher water ratio applications, we recommend adding 2 ounces of Purple Ice per quart of cooling system capacity.
When used with antifreeze, Purple Ice should be added once a year or every 30,000 miles (48,280 km), whichever comes first, in order to maintain proper performance. When using Purple Ice in a cooling system running straight water, Purple Ice should be added once a year or every 15,000 miles (24,140 km), whichever comes first.
No, a higher concentration of Purple Ice than recommended will not harm the cooling system or engine. However, going well beyond 2 ounces of Purple Ice per quart of coolant won’t offer any additional cooling benefit, but may result in some foam generation in the system.
Yes. Purple Ice may be used in diesel engines for improved heat transfer as well as reduced cavitation.
Fuel Additives
It forms non-combustible gums that form deposits in fuel systems / combustion chambers, which decreases engine performance / fuel economy and increases emissions.
No, but it will prevent it from degrading any further, and allow it to be safely used without forming engine deposits.
When used at our recommended dosages, Max-Clean will stabilize fuels with less than 10% ethanol for up to 2 years. For fuels containing 10% or great ethanol content, Max-Clean will stabilize for up to 1 year.
Max-Clean is suitable for use in all liquid automotive-type fuels, including gasoline, ethanol, diesel, and bio-diesel.
Yes, it will not harm catalytic converters or oxygen sensors, and will clean/remove deposits in port injected, direct injected, and carbureted engines.
It contains polyetheramine (PEA), a proprietary detergent that solubilizes deposits so they can be burned during the combustion cycle in an engine.
No, but a cleaner burning engine has a reduced octane requirement,which allows less expensive, lower octane gasoline to be used without the risk of detonation.
Pour entire contents of can into a nearly empty tank and refuel. One (1) can treats up to 20 gallons. For tank sizes outside of this range, use one (1) ounce per gallon. In 2-cycle engines, to ensure best mixing with the 2-cycle fuel/oil mixture, we recommend adding Max-Clean to the gas tank prior to putting the 2-cycle fuel/oil mixture into it.
Royal Purple Max-Boost provides up to 30 points (3 octane numbers) increase in fuel octane, which meets or exceeds the boost of any other non-lead consumer octane boosting product available, and it carries the added benefits of stabilizing fuel, cleaning deposits, and providing protection for non-hardened exhaust valve seats (lead substitute). It effectively replaces 2 to 4 products, depending on your needs.
Each 16oz bottle of Max-Boost treats up to 25 gallons of gasoline with a recommended dosage of 1 ounce of Max-Boost per gallon of fuel. To ensure best mixing with fuel, it is best to add Max-Boost to your fuel tank at fill-up, prior to putting the fuel into the tank.
Max-Boost is safe for use in any gasoline and gasoline/ethanol blend of fuel, but many non-performance cars do not benefit from high octane fuel. If the fuel stabilization and cleaning benefits of Max-Boost are what you want, rather than the increase in octane, we recommend Royal Purple Max-Clean Fuel System Cleaner & Stabilizer.
Yes, Max-Boost works in any gasoline or gasoline/ethanol blend fuel delivery system and will work great for any engine that runs best with high octane fuel.
Royal Purple Max-Tane is better than any other consumer diesel additive because it does the job of every other consumer diesel fuel additive. Max-Tane is a cetane booster, a fuel lubricity enhancer, a fuel anti-gel, fuel system and injector cleaner and improves fuel economy up to 10%. Royal Purple Max-Tane effectively replaces up to 4 other diesel fuel additive products.
Royal Purple Max-Tane is formulated for use in any diesel-type vehicular fuel including #1 and #2 diesel, biodiesel, and ultra-low sulfur diesel fuels.
Royal Purple Max-Tane is available in a 20 ounce can. Each 20 ounce can treats up to 100 gallons of fuel. To ensure best mixing with fuel, it is best to add Max-Tane to your fuel tank at fill-up, prior to putting the fuel into the tank.
Royal Purple Max-Tane is available in a 20 ounce can. Each 20 ounce can treats up to 100 gallons of fuel. To ensure best mixing with fuel, it is best to add Max-Tane to your fuel tank at fill-up, prior to putting the fuel into the tank.
It is the only additive formulated specifically for direct injection gasoline (DIG) engines, and is the most concentrated PEA fuel injector cleaner available on the market today.
It is polyether amine, a powerful detergent proven most effective at removing coked deposits found on injectors in DIG engines.
No, it can be used with any type of injectors, including port injectors, and diesel injectors.
It cleans injectors and restores proper flow, which optimizes injector spray patterns and better atomizes fuel as it enters the combustion chamber.
Yes, it can be used in any gasoline and ethanol blend (E5, E10, E15, E85, etc.), and it provides the additional benefit of ethanol stabilization.
For best results, use at every fill-up. Use every 3,000 miles, or as necessary, to maintain adequate engine operation.
Max-Atomizer is a stand-alone fuel injector cleaner. Max-Clean offers the injector cleaning of Max-Atomizer and also provides cleaning of piston crowns and combustion chambers, fuel stabilization, and demulsification of water from ethanol-containing fuels.
Motor Oil
Royal Purple API-licensed motor oil is formulated specifically to meet current American Petroleum Institute (API), International Lubricant Standardization and Approval Committee (ILSAC), and Association des Constructeurs Européens d’Automobiles (ACEA) specifications for new vehicle warranties. Over the last several years, these specifications have become increasingly restrictive on certain additives, particularly those commonly used for anti-wear. As such, API/ILSAC compliant oils aren’t the best solution for consumers that have modified their vehicles or those simply looking for the greatest performance.
HPS is formulated with consumers in mind. This motor oil line offers the incredible performance and protection provided by Royal Purple’s proprietary Synerlec technology as well as a dramatically enhanced anti-wear package. HPS is also the choice for those seeking to maximize horsepower and torque, while reducing wear, heat and fuel consumption. HPS is the most robust engine oil Royal Purple makes for non-racing applications.
No. Testing has shown no short or long term adverse affects on catalysts in mechanically sound vehicles.
Absolutely. All viscosities of HPS are formulated for use in gas and/or diesel engines and are ideal for those with modified diesels or those simply looking for more performance out of their diesel.
Yes. Royal Purple lubricants are fully compatible with mineral or synthetic oils. No special procedures are necessary when switching to Royal Purple. We recommend against intentionally creating a mixture of different brands or product lines of engine oils.
Yes. Mileage and/or age is not a factor when used in a mechanically sound engine. In high-mileage applications, we do recommend running a minimum of two short 3,000 mile (5,000 km) intervals before extending the oil drain intervals. This will enable Royal Purple’s high solvency to remove existing deposits gradually; if excessive, such deposits can restrict oil flow, as well as reduce the oil service life significantly.
Yes. Royal Purple currently offers many viscosity grades of API-licensed motor oils1. To allow for proper break-in of the engine, Royal Purple recommends waiting until the manufacturer’s first scheduled oil change or a minimum of 2,000 miles (3218 km) in new gasoline engines. Allow a minimum of 6,000 miles (9656 km) before using Royal Purple in diesel engines.
Royal Purple suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty using Royal Purple API-licensed SAE motor oils. With Royal Purple HMX® and HPS series oils, drain intervals may be extended to 15,000 miles (20,000 km) or one year, whichever occurs first in street-driven, mechanically-sound vehicles. For guidelines specific to your vehicle, we recommend contacting our technical department 888-382-6300.
Once manufacturer warranty is no longer a concern, with the Royal Purple API-licensed SAE motor oils drain intervals may be extended up to 12,000 miles (19,200 km) or one year, whichever occurs first in street driven, mechanically-sound vehicles.
Royal Purple suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty. Vehicles no longer under warranty using Royal Purple Duralec Super, Duralec Ultra, or HPS engine oils, that hold 10-quarts of oil or more, can extend oil change intervals up to 15,000 miles (24,140 km) or one year, whichever occurs first in street-driven, mechanically-sound vehicles. For smaller capacity engines, oil change intervals should be every 12,000 miles (19,312 km) or one year. For guidelines specific to your vehicle, we recommend contacting our technical department at [email protected]
Yes. Royal Purple Motor Oils are composed of a proprietary formulation of synthetic base oils and synthetic additives containing iso-paraffinic diluents.Royal Purple Break-in oil is the only non-synthetic automotive engine oil offered by Royal Purple.
Properly formulated synthetic oils will generally not cause an engine oil leak. Synthetic oils possess a higher degree of natural solvency, which can clean and remove deposits left by previous oils. The removal of extensive oil deposits can expose marginal or damaged oil seals, which may then leak. If an engine currently has excessive oil consumption (i.e. greater than 1 quart / 1,000 miles) the recommended course of action is to solve the oil consumption problem before switching to a synthetic.
No. We strongly recommend against using any oil additives as do most automotive manufacturers. Engine oils are formulated with a fine balance of additives (anti-foam, corrosion inhibitors, anti-wear, detergent / dispersants, oxidation inhibitors), and more is not necessarily better. The use of an oil additive could upset the balance resulting in reduced performance.
No. The dye that’s used to color the oil dissipates shortly after being put into service. The oil will appear brown at some point.
Yes. All Royal Purple® engine oils contain the zinc/phosphorus compound zinc dialkyl dithiophosphate (ZDDP), but the maximum amounts are restricted by the current API oil specifications. For stock, non-performance automotive street applications, API SN licensed oils are OK. For better wear protection, Royal Purple HPS and XPR lines of engine oils are formulated with a higher concentration of the zinc and phosphorus anti-wear additive and are suitable for ALL flat tappet and roller tappet camshaft valve trains. For a specific recommendation, contact our tech department at 888-382-6300.
Yes. For stock, non-performance valve trains, Royal Purple API-licensed oils (API SN and ILSAC GF-5 licensed) are OK. For upgraded performance flat tappet camshafts, and vintage high performance engines, we recommend our HPS or XPR engine oils. For a specific recommendation, contact our tech department at 888-382-6300.
While no special oil filter is required, we do recommend upgrading to a high quality oil filter. A high quality filter will prevent contaminants from circulating through the system and causing damage.
For best performance and filtration, we recommend Royal Purple Extended Life Oil Filters. See our oil filter information page for more details or visit our dealer locator to find the dealer nearest you that carries our new filters.
Yes, HMX is fortified with Royal Purple’s proprietary Synerlec additive technology as well as additional seal conditioners beneficial to higher mileage engines to maintain elasticity of gaskets and seals. HMX is also formulated with a slightly higher amount of anti-wear additive to provide more wear protection for older engines.
A properly formulated High Mileage oil like HMX will help reduce oil consumption and restore lost power. HMX is chemically enhanced to revitalize hardened seals reducing oil consumption common in higher mileage engines.
LOW-SPEED PRE-IGNITION
In the continuing effort to increase passenger car and light truck fuel economy, automakers have employed a “down-sizing” and “downspeeding” strategy to current vehicle powertrains. The down-sizing is accomplished with the use of Turbocharged Gasoline Direct Injection (TGDI) engines.
The TGDI engines provide the torque and power output of larger displacement, non-turbo engines while returning fuel economy approaching that of smaller displacement, non-turbo engines.
For example, late model TGDI 2.0 Liter engines commonly produce power levels equaling 3.0L to 3.5L V-6 engines from 5 to 10 years ago. The extensive fuel, ignition and boost adjustability and control that TGDI engines have allows them to be tuned with maximum torque achieved at very low engine speeds (by 2,000 rpm is typical). By optimizing torque to lower operating speeds, greater fuel economy is possible. The down-speeding of the powertrain involves the use of transmissions with an increased number of gear ratios with smaller steps between each ratio.
Automatic transmissions with 8 to 10 forward gear ratios are now common, while 4 to 6 speed automatic transmissions were most common in the recent past. With the increase in gear ratios and the small step change between each gear, the power train can keep the engine speed low and near the torque peak of the engine while allowing good acceleration and highway speeds.
Continuously Variable Transmissions (CVTs) are used in the same manner as they provide a step-less, continuous change in gear ratio with infinite gear ratios theoretically available. By using a smaller displacement engine that is kept in a low speed and efficient operating range, fuel economy is optimized.
Pre-ignition and detonation, commonly referred to as “knock”, are abnormal combustion events that can occur in gasoline engine combustion chambers. Preignition and detonation result in a huge spike in combustion pressure and temperature that often results in damage to the engine. TGDI engines offer very high power density (power per displacement) and operate most efficiently at low engine speeds. Because of this, they are susceptible to a form of pre-ignition called Low-Speed Pre-Ignition (LSPI). Typical preignition and knock are caused by hot-spots on surfaces in the combustion chamber, and can be controlled by altering the spark ignition timing of the engine. LSPI tends to be caused by particles in the combustion chamber, either tiny liquid droplets of engine oil, or loose deposit particles caused by engine oil or fuel. Currently, the only way to control LSPI and help prevent it from occurring during engine operation is to increase the fuel delivered to the combustion chamber, which reduces the fuel economy of the engine.
Current research indicates that LSPI can be reduced with new chemistry technology used in gasolines and engine lubricants. Some chemical compounds traditionally used in fuel and lubricant additives may contribute directly to LSPI or to the formation of deposits that can cause LSPI.
In an effort to provide the highest performing lubricants that are safe and effective in any engine, Royal Purple High Performance API licensed engine oils are formulated with only the most advanced additive technology that is tested and proven to be effective at reducing and eliminating lubricant induced Low-Speed Pre-Ignition. Royal Purple API SN/ILSAC GF-5 licensed engine oils meet or exceed all industry and OEM requirements in reducing LSPI events while also continuing to provide the highest level of lubrication performance and wear protection for the engine.
Yes. Royal Purple currently offers many viscosity grades of API-licensed, warranty compliant motor oils. To allow for proper break-in of the engine, Royal Purple recommends waiting until the manufacturer’s first scheduled oil change or a minimum of 2,000 miles in new gasoline engines. Allow 6,000 to 8,000 miles before using Royal Purple in diesel engines.
A PROPRIETARY ADDITIVE TECHNOLOGY THAT SETS ROYAL PURPLE SYNTHETIC OILS APART FROM THE COMPETITION
Synerlec additive technology makes Royal Purple unique—and it’s a big reason why Royal Purple products perform like no other lubricants on the market. This man-made additive improves our products on a molecular level, by creating high-strength ionic bonds with metallic surfaces that allow our engine oils and other lubricants to react to sustained heat and pressure, not by breaking down like regular oil, but with increased film strength and lubricity.
With extended use, Royal Purple synthetic lubricants with Synerlec improve the surface condition of metallic surfaces by smoothing inherent surface roughness, actually reducing friction and improving lubrication of internal moving parts. That’s why we put it in every Royal Purple lubricant we can, from our performance upgrade synthetic motor oils and gear oils to gun oil and any other types of Royal Purple synthetic lubricants. So if you’re looking for high performance synthetic oil, look no further than Royal Purple synthetic lubricants with Synerlec.
Motorcycle Oils
Follow the manufacturer’s recommendations regarding viscosity. Most manufacturers recommend a 10W-40 for 4-cycle, liquid-cooled motorcycles. Air / oil cooled motorcycles typically specify a 20W-50. Check your owner’s manual for verification or contact Royal Purple’s Automotive Technical Department at 888-382-6300 for assistance.
Royal Purple® suggests adhering to manufacturer’s recommendedoil change intervals for vehicles under warranty. Vehicles that are no longer under warranty can frequently double or triple the number of miles between oil changes depending on the vehicle, its condition, the way it’s used (excessive idling), and the oil filter that is used. For guidelines specific to your vehicle, we recommend contacting our technical department at [email protected].
For 2-cycle motorcycles with a separate transmission fluid reservoir, we recommend Royal Purple Synchromax or an engine oil from our Max-Cycle or HPS series. Please contact Royal Purple Automotive Technical department at 888-382-6300 for assistance
Royal Purple Max-Cycle® 10W-40 or 20W-50 motor oil may be used in the primary tank. For transmissions, Royal Purple recommends Max-Cycle 20W-50 or Max Gear 75W-90. NOTE: DO NOT use Max Gear lubricants in the primary or in any other component containing a wet clutch.
For all Harley Davidson and other air-cooled V-twin motorcycles, we recommend Royal Purple Max-Cycle 20W-50. If the owner’s manual recommends a 10W-40 or 15W-40, Max-Cycle 10W-40 is the best option.
No. Royal Purple Max-Cycle engine oils are rated JASO MA2 in the JASO T903:2011 Clutch Friction Test. MA2 is the highest wet clutch compatibility rating.
Yes. Royal Purple uses a different additive chemistry than most manufacturers, which is the very foundation of the benefits RP offers. This technology has a distinctive odor, different from the common odor of exhaust gases to which most have become immune.
Racing Oils
Yes. Royal Purple XPR® racing oils are fully formulated engine oils with complete additive packages needed for long-term use. The XPR ultra-light viscosity 0W-8 is considered suitable only for dedicated competition engines that are built specifically to use very low viscosity engine oils. Non-ultra light viscosities, XPR 0W-20, 0W-30, 5W-20, 5W-30, 10W-40 and 20W-50 may be used in street driven and daily driver applications, street and track duty vehicles and dedicated competition applications with gasoline or exotic fuels. Pleas note: Royal Purple XPR racing oils do not conform to API and/or ILSAC licensing requirements and should not be used when manufacturer’s warranties are an issue.
Yes. Royal Purple’s lubricants can be used with exotic fuels. For the best protection, Royal Purple® has formulated its XPR®specifically with this in mind. The XPR oils are formulated to combat fuel emulsification to hold up even better than Royal Purple’s other engine oils in alcohol and methanol applications. Royal Purple Nitro Plus™ oils are the best choice for blown alcohol, Nitro-methane and any other race application with excess fuel dilution. Royal Purple’s other synthetic engine oils will still perform better than conventional racing oils; however, significant fuel dilution will reduce the effectiveness of these oils much more than the XPR and Nitro Plus oils.
In most cases, vehicles with properly functioning cooling systems can reduce oil temperatures by 5-20°F by using Royal Purple.
Royal Purple API-licensed motor oils are formulated to provide unparalleled performance and protection while complying with API and ILSAC specifications. XPR and Nitro Plus racing oils vary in viscosity and formulation from the API-licensed motor oils to provide the greatest performance and protection possible, without regard to API, ILSAC, or OEM specifications.
We do not restrict any automotive product from any retailers that carry Royal Purple consumer products. Any lack of availability of Royal Purple products at local retail stores is due to the choices made by the store owners/buyers. Retailers choose the products they stock and order for a myriad of reasons. Many times, a local retailer will special order Royal Purple products if you can provide the part number. Another option is to shop online. Several online retailers, including Amazon.com, JEGS.com, Lucky7Trucks.com, PacePerformance.com, and SummitRacing.com carry just about all Royal Purple automotive and consumer products, and they will ship directly to you.
No. Royal Purple has not found any evidence that it shows deterioration in performance after being subjected to race conditions. Excessive fuel dilution may effect the performance of any engine oil; however, XPR and Nitro Plus oil offer greater protection than other oils even with excessive fuel contamination.
Transmission & Gear Oils
Check your owner’s manual for verification. A complete list of warranty applications can be found on our Max ATF product page.
No. All viscosity grades of Max Gear are formulated with limited-slip friction modifier necessary for some limited-slip differentials. No additional additives should be necessary.
Yes. Max Gear is completely non-corrosive to soft yellow metals (brass, bronze, copper) so it is synchronizer-safe like a GL-4 gear oil. However, because of Royal Purple’s proprietary Synerlec additive technology, Max Gear oils retain the load carrying and shock protection capability of a GL-5 gear oil.
