Extended Oil Drain Intervals For Passenger Cars

Lubes ‘n’ Greases (June 1995) asks, “Extended Drain Intervals: Yes or No?”

Representatives of the auto and lube industries both answer, “yes”! What has enabled – or forced – these industries to rethink their positions … and bring them in line with the position long held by AMSOIL?

“Back in the 1950s,” Lubes ‘n’ Greases begins, “drivers of passenger cars needed to change their oil about every 1,000 miles. Today, recommendations for most U.S. cars vary from 3,000 to 7,500 miles or six months between oil changes.”

Today, faced with environmental pressures and a desire to make cars maintenance-free, automakers are beginning to look, once again, at their oil drain interval recommendations. According to Lubes ‘n’ Greases, “At the last SAE Technical Committee 1 meeting, Mike McMillan of General Motors, speaking on behalf of Detroit’s Big Three, stated that for the next generation of oils, one of the top three goals should be ‘protection for extended drain intervals,’ right after fuel economy and reduced emissions. ‘The push is on,’ he urged. ‘We need to look very seriously at this.”

Those outside the Big Three are examining the issue, as well. Rudolf Thom, a Mercedes-Benz automotive engineer, and Wolfgang Warnecke, a Deutsche Shell lubrication engineer, are working together to “explore how engine oil stress can be measured and how that information can be harnessed to develop improved oil drain systems.” Their goal: protecting the engine and optimizing the use of base oils and additives.

Relentlessly pursuing those goals for twenty years, AMSOIL INC. has accumulated an impressive body of evidence to support its paired claims of unsurpassed engine durability and extended oil drain service.

AMSOIL and the Duluth, Minnesota Police Department conducted a joint demonstration of the AMSOIL Trigard system. Four Ford LTD police vehicles with 351 CID gasoline engines used the system for six months. The cars travelled an average 34,652 miles.

Police service is tough service, alternating between hours of idling, extended periods of stop-and-go driving and occasional high speed activity. None of the vehicles required an oil change during the demonstration. Compared to a group of control vehicles, the Trigard equipped police cars cost $413.91 less to maintain. Most of the savings came from reduced labor costs, a means of quantifying automaker’s “new” goal of maintenance-free cars. (See the G-1067 Fleet and Field Trials Book 1 for more information.)

AMSOIL and a New York City taxi-cab fleet conducted a joint demonstration of the long drain capability of AMSOIL Synthetic 10W-40 Motor Oil, the AMSOIL Full-Flow Oil Filter and the AMSOIL By-Pass Oil Filter. Sixteen cabs, equipped with Chevrolet 229 CID V-6 engines, were divided into four groups of four vehicles. Group A, the control, received conventional oil, conventional filters and continued using the fleet’s customary 3000-mile drain intervals. Group B received AMSOIL Synthetic 10W-40 and the AMSOIL Full-Flow Oil Filter and received oil changes at 6000-mile intervals. Group C received the same products as did Group B and received oil changes at 12,000 mile intervals. Group D received an AMSOIL By-Pass Oil Filter in addition to the products received by Groups B and C and received no oil changes during the course of the one-year, 60,000-mile demonstration.

Like police service, taxicab service is tough, replete with idling, stop-and-go driving and high speed stints. Yet, the AMSOIL products over-matched their conventional counterparts, even though they saw much longer service.

In fact, the independent testing facility charged with the responsibility of compiling test data wrote, “The data presented in this report indicates that AMSOIL Synthetic SAE 10W-40 passenger car motor oil formulation as described here provided protection of test engines from excessive wear and deposit formation far beyond the normal 3000-mile change interval.” The test provided clear evidence that engine protection and extended oil drain service are quite compatible, given appropriate quality products. (See the G-1068 Fleet and Field Trials Book 2 for more information.)

AMSOIL and the State of Wisconsin conducted a joint demonstration of the long drain capabilities of several AMSOIL products, including AMSOIL Synthetic 10W-30 Motor Oil. The demonstration vehicles included 32 AMC Alliance cars with 1.4 liter engines, divided into four test groups of six cars each and a control group of eight cars. During the course of the demonstration, the test vehicles received four oil changes, while the controls received twelve.

Used for state business, the Alliance vehicles experienced driving conditions very similar to those experienced by privately owned passenger vehicles. Demonstration results showed lower levels of wear metals in the oil samples taken from the test vehicles than from the samples taken from the controls: again, clear evidence that engine wear may be kept well in check during extended oil service with appropriate quality oils. (See the G-1067 for more information.)

AMSOIL and thousands of passenger vehicle owners are currently conducting an ongoing “joint demonstration” of the long drain capability of AMSOIL synthetic motor oils under the auspices of the innovative Trigard Program. Since the introduction of Trigard in 1983, motorists have participated in the program, which allows them to use AMSOIL synthetic motor oils indefinitely. The program teams AMSOIL synthetic motor oils, the AMSOIL Full-Flow Oil Filter, the AMSOIL By-Pass Oil Filter and an independently administered program of used oil analysis to safeguard engine durability while maintaining an oil as long as the analysis finds it fit for continued use.

Is the industry ready for widespread use of Trigard programs? Perhaps not yet, but Lubes ‘n’ Greases notes, “Lubrizol Corp. theorizes there will be a shift toward changing oil on an ‘as needed’ basis, rather than following a predetermined schedule.” Current on-board diagnostic technology could be used to measure engine rpm, number of cold starts, coolant temperature and driving severity and programmed to alert the driver when the oil needs changing.

Mercedes-Benz AG’s Thom and Deutsche Shell’s Warnecke also propose oil drain intervals become flexible, based on engine requirements, performance of the oil, individual driving habits and severity of service. They, too, see on-board diagnostics as key and propose its use in a system they call the Oil Stress factor.

“‘Higher values of the Oil Stress factor would mean increased oil stress, and thus faster aging of the oil,’ the two noted. ‘This leads either to reduced oil drain intervals or the necessity for only high quality, high performance engine oils.”

Engine design changes may also increase oil life: increasing sump capacity reduces the stress on the oil, and using oil coolers to reduce oil temperature to an average 100° C reduces thermal aging of the oil. It’s interesting to note that use of AMSOIL synthetic motor oils and the AMSOIL Dual Remote Oil Filtration System both increases sump capacity and reduces oil temperature. And, of course, the Dual Remote offers the oil service life enhancing benefit of ultra-fine filtration.

North American and Japanese automakers, through the International Lubricant Standardization and Approval Committee, are working on a future generation of engine oils, GF-3. Developers of GF-3 oils will focus on three primary auto maker needs: reducing tailpipe emissions, increasing fuel economy and extending oil service life. GF-3 oils are scheduled to hit the commercial marketplace in 2000.

The future isn’t very far away. And the future belongs to AMSOIL, a company with the foresight, 23 years ago, to develop and market long drain motor oils and to compile the evidence to support extended drain use of their remarkable products.

*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for the use in the application shown.

Reproduced With The Permission Of AMSOIL INC. All Rights Reserved.

SLS Notes: Keep in mind that this article was written in 1995, 25 years ago. Now think of all the advances that have been made in engine design, performance and lubrication. In 1995 the API Service Classification was SH. Since then we have had SJ, SL, SM, SN, SN+ and now SP. That’s 6 generations of improving standards.

ILSAC was working on the GF-3 specs. that were to be released around the year 2000 but in 1995 the current ILSAC standard was GF-1. (GF-2 went into effect in 1996.) They are now at GF-6 (A & B but that’s for another article.) Again, significant improvements in the quality of motor oils. And again, AMSOIL was leading the way with oils that already met or exceeded the new standards when they were announced by API and ILSAC so lubricant manufacturers could begin working on formulations to meet the new standards.

There are still people who insist on changing oil every 3,000 to 5,000 miles, including some of my customers. Oils have improved significantly along with engine technology since 1995 so, are they wasting money (and resources)? In most cases, yes. I say “most” because there are several of the new technologies that produced unexpected problems.

GDI (Gasoline Direct Injection) for example can end up producing fuel dilution in the oil causing viscosity breakdown, reduced lubrication and additional vapor contaminants in the engine oil sump. EGR systems then pull these extra contaminants back into the intake system to reduce emissions and you can get deposits that build up on intake valves leading to poor engine performance. If you have one of these engines you want to use the highest quality synthetic oil you can get to combat the lubrication breakdown and change the oil at the manufacturers recommend change interval.

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