Tech Stuff

Engine oil change intervals

In a recent editorial, I commented about the validity of extended oil change intervals that are commonly promoted today by auto makers (ASP September/October 2014 issue). My intent was to provide my own opinion, and not to promote the increased sale of oil (read the editorial in our digital edition on www.autoserviceprofessional.com). This topic has obviously hit a nerve among our readers. Following are just a few of the letters we’ve received regarding this subject.- Ed.


Oil changes are cheap insurance, in my opinion. I have always changed the oil on all my vehicles around the 3,000 mile mark using a good quality oil and a new filter. I have never had a serious engine problem thanks to this regular engine maintenance. Any valve cover I may have pulled to reseal, or intake manifold, always showed a very clean engine inside. “Pay a little now, or a lot later,” I have found has held true through the years.

One of the worst engines I have ever seen due to the lack of oil changes was a customer’s vehicle I worked on in a Chevrolet garage in the early 1990s. A customer’s vehicle with 23,000 miles on it came in with an engine knock. It was an Astro van that had been purchased new from our dealership. Records showed the only oil change was at 12,500 miles. The customer said they thought all they had to do was keep adding oil to keep the level up. Needless to say, pulling a valve cover in the vehicle to check the engine valve train showed the buildup of a black sludge throughout. The motor was toast, a prime example of what can happen when not changing your oil on a regular basis.

Kurt Schleicher, Customer Service Rep

U.S. AutoForce


Regarding Auto Service Professional’s recent editorial by editor Mike Mavrigian, I could not agree more. I took a variable valve timing (VVT) course a short time ago, and the #1 problem with all the VVT vehicles by all manufactures was sludge and dirty oil. And what do the manufactures do? They EXTEND the oil change intervals! Is this part of a hidden agenda?

P.S.: When my customers ask me what oil to use, I tell them FRESH.

Joel Sylvia

S&S Auto Repair


Mike, you are so on target with your comments.

I have been in automotive service all my life — 35-plus years. Fluids have always been one of the most important things that will protect your investment, especially in today’s high technology vehicles.

My company services over 5 million vehicles a year. I also maintain a technical service hot line. The reason I bring that up is because we field a large number of oil-related problem calls, more than we have, say, 10 years ago.

One of the popular oil-related calls we get today concerns variable valve timing DTCs with the engine light on. Many of the newer models utilize these systems. We are finding that customers don’t check their oil or anything under the hood like they used to.

These VVT DTCs many times are caused by low oil levels or neglected oil systems. Because of this, if we find low or dirty oil we start the diagnostic by performing a good oil change with the proper oil, and clear the DTC and send the driver on their way. That is the fix, in many cases. If the DTCs come back, and they will if there is a problem, then we get into some real diagnostics. Unfortunately, at this point any money that the customer saved on extended oil changes will now need to be spent on corrective services. In many cases, we find gummed-up solenoids, plugged oil passages or plugged screens. I could go on talking about VVT problems, but I think you get the point.

One thing consumers need to know is that the proper oil viscosity is most important these days. Flow characteristics are most important to VVT systems and the high-tech valve train.

Here is another oil change interval-related problem that we are seeing. In the past, tire rotations would get done every other oil change. Today, if you go with, say, the GM OLS system recommendation for an oil change, you may not see that car for 12 months, maybe even past 7,500 miles between oil changes. What if the tires don’t get rotated with every oil change? Tires can be finicky if they are left on the same axle too long. Noise and abnormal wear is usually not reversible on a tire. This is another hidden expense to the extended oil change interval. We are seeing tires just getting destroyed due to lack of rotations.

One more thing. This is a little off-the-wall. Do you know that there is a new regulation out there that prohibits a service station from putting an oil change sticker on the windshield recommending the next service interval? We can only put the mileage and date the service was done last. I am not sure exactly how many states this applies to, but it is in most that we are in.

As I said at the beginning, one of the most important things that will protect your investment is clean fluids. And if you’re worried about the environment, recycled oils today are just as good and sometimes better than new oil.

Jim Lynch, Training Director

Monro Muffler Brake Inc.

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