Q. How can a lower viscosity oil still protect my engine? Isn't thicker better when it comes to long engine life?
A. Lower viscosity oils or oils with a lower W rating such as 10W-30, 5W-40 or 5W-30 can be formulated for both engine durability and fuel economy.
When a low viscosity oil can demonstrate proven engine durability, the benefits of significant fuel savings while sustaining optimum engine life is achievable. However, emphasis needs to be placed on how the oil is formulated and tested. Just lowering the viscosity grade without providing a performance enhancing additive technology could lead to higher engine wear and shortened engine life.
With the push to improve fuel economy, the unknowing consumer may be inclined just to listen to the fuel-saving message and not check out product performance support behind the claims.
Overall, properly designed, low viscosity heavy-duty engine oils can provide fuel savings, reduce cold engine cranking with reduced dependency on energy consuming block heaters, and improved battery and starter life, reduce cold weather start wear and superior high temperature performance.
Q. Why can't I use a CI-4 Plus engine oil in an engine that calls for CJ-4?
A. Engines produced after 2007 are equipped with diesel particulate filters that require the use of CJ-4 oils. CJ-4 oils have been formulated to provide optimum compatibility and durability for DPFs. Using CI-4 Plus oils can shorten the service life of the diesel particulate filter, leading to higher maintenance costs or even replacement of the DPF.
Q. If an oil meets the API category and any other standards set by my engine maker, what's the difference between that and a premium oil?
A. Many lubricant consumers refer to the basic engine manufacturer approvals and API credentials to determine whether or not the oil selected is suitable for service and complies with component manufacturer recommendations.
For example, the API provides a list of licensed and registered engine oil products.
However, many oil brands provide several products within their product lines that may all carry the same API credentials as well as engine manufacturer approvals.
An engine oil manufacturer may offer several heavy-duty engine oil options, all listed as API CJ-4, with all the same engine manufacturer approvals or recommendations. The confusion comes when attempting to differentiate whether or not there is true performance advantage in the number of options within the brand. The scope of this message cannot provide all the details needed to offer an adequate response but here are few basic comments:
a. What a heavy-duty engine oil is listed and licensed at is not the only thing to consider. The testing and certification process can produce different performance results. For example, a test used to qualify CJ-4 oil can have as much as a 50% variance in allowable passing limit versus the "headroom" performance that can be achieved with premium additive technology. Why is this important? It may not be for some equipment owners unless you need optimum engine life, operate in severe conditions or need longer service life out of your engine oil.
b. Oils also can be further tested in real operating conditions or in real-world fleet conditions. This further shows an accurate level of performance by providing real-world field testing results. This, combined with engine teardown inspections at extended mileage levels, provides another level of evaluation. Premium performing oils will show outstanding results versus oils that are produced just to meet minimum passing levels.
c. Before buying an oil at face value that it meets all the credentials, an equipment owner should at the very least ask a supplier specifically what level of performance confirms and supports the advertised claims.
Q. Can synthetic lubes extend the life of transmissions, axles, etc.?
A. Yes. Properly formulated synthetic drive line lubricants can offer extended lubricant service and component life compared to mineral oil or conventional type gear oils.
Consult with your drive line manufacturer to find out what the lubricant and service recommendations are for your vehicles.
However, there are different designs and compositions of synthetic oils and just because an oil is listed as synthetic, it may not automatically provide optimum performance for either lubricant service or component life. Ask the supplier what type of synthetic base is used to produce the synthetic drive line oil.
Q. Do natural gas engines need different oils?
A. Yes. Most leading diesel engine manufacturers typically recommend engine oils that are specifically designed and formulated for engines using CNG or LNG. Oils, referred to as "Fleet Oils" or oils designed to be used in diesel fueled engines are generally not recommended. One of the leading engine manufacturers has reported that "Valve Torching" can result from using the fleet oils in the lean burn conditions of CNG fuel engines. It is understood that stocking only one product is more desirable in mixed diesel and CNG fleets, but it is highly recommended that the equipment owner consult with the engine manufacturer and find out their engine oil recommendations before settling on the "One Oil" for both diesel and CNG engines.
Q. How do they come up with the API categories?
A. The API (American Petroleum Institute) categories are established through a joint effort of engine manufacturers, oil suppliers and chemical additive suppliers with oversight by API.
The purpose of the API performance category program is to ensure that a quality standard is established and maintained over the years.
The program is a voluntary engine oil testing protocol and certification process using industry-standard physical, chemical, and performance tests. If an oil can meet the minimum passing limits of these tests, it can be marketed as meeting that quality standard level, or in other words meeting the API category.
The result is an Engine Oil Licensing and Certification System list available on APIs website http://eolcs.api.org/ which lists products that qualify and meet the testing standards established by this partnership.
It also is important to know that even though an engine oil supplier may meet the basic requirements of a given API category, there is still additional headroom performance capability that can be achieved with higher performance products that go beyond that minimum. There are multiple choices within any engine oil brand. Find out what the difference is among the various oils offered by any one supplier, since performance can vary even though basic specifications are listed.
Q. Will a synthetic oil help improve mpg?
A. The key factor in improving fuel economy is choosing the right viscosity grade. In comparison to an SAE 15W-40, SAE 10W-30, 5W-30 and 5W-40 oils now have a history of improving fuel economy as much as 4% in different types of operations. Most if not all 5W-40 or 5W-30 heavy-duty engine oils are marketed as full synthetic oils, whereas most 10W-30 oils are either conventional or synthetic blend oils. The key point is it is the lower viscosity, not the synthetic component that delivers the improvement in fuel efficiency.
Q. What do I need to look for in an oil to use for extended drain intervals?
A. First, make sure you know your engine manufacturer recommendations and guidelines.
Second, most heavy-duty engine oil suppliers have multiple performance levels available. Considering the investment cost of a diesel engine, downtime and overall maintenance costs, it is highly recommended to investigate what products are available to optimize engine oil performance and engine protection under extended oil change intervals.
Third, implement and carry out a quality oil analysis program, partnering with an oil analysis laboratory or your engine oil provider. Failure to go about extended engine oil change intervals correctly can only result in problems down the road. It is recommended to use or at least inquire about premium or higher performance engine oils, used in combination with a quality oil analysis program.
Q. Do I need different oil if I'm using a biodiesel blend?
A. It has been reported that higher biodiesel blends above 5% may increase the rate of oil oxidation and fuel dilution. This, however, is still under further review. To be on the safe side, we recommend using higher performance heavy-duty engine oils, especially when operating in severe conditions or when employing extended drain intervals. It is also recommended to utilize an oil analysis program to monitor oil condition.
Q. How can using different engine oil help improve my fuel mileage?
A. Low viscosity heavy-duty diesel engine oils, when compared to SAE 15W-40, may provide levels of improved fuel efficiency.
SAE 10W-30, 5W-40 and 5W-30 are examples of lower viscosity grades that have field-proven results of improving fuel efficiency.
Q. What is an oil stabilizer?
A. The word "stabilizer" can be thought of as an aftermarket additive which claims some type of performance improvement. There are many variations of these additives claiming everything from reduced oil consumption, improved fuel economy, reduced engine deposits and longer engine oil service life. In addition to what an oil stabilizer is, one should also consider the following before adding a stabilizer to your engine oil.