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Oil Change 101
Something as simple and routine as an oil change has suddenly become more complex and confusing. There are many opinions on this subject and we will offer ours. The two most confusing aspects of oil changes are the interval and what type of oil to use.
Undoubtedly, engine and engine oil technology has come a long way in a short period of time. Engine manufacturers have been able to design and mass produce engines today with materials and manufacturing processes that Henry Ford couldn’t have imagined in his wildest dreams! Engines certainly don’t “wear out” like they used to, and are superior in many ways to those of just a couple of decades ago. Credit goes to the engineers who design the engines and to the engineers who are continually improving engine oil. However, with changing technology, unforeseen issues always seem to arise.
With ever-increasing demand for greater fuel efficiency and lowering of emissions, engine manufacturers are adding such things as Variable Valve Timing (VVT) technology and Cylinder Deactivation technology. In short, VVT allows the engine’s computer to alter camshaft timing (which has been fixed since the beginning of time) for improved performance, reduced emissions and improved fuel economy. Cylinder Deactivation allows the engine’s computer to selectively and seamlessly (well, almost) deactivate cylinders from firing under certain conditions, which reduces emissions and improves fuel economy. Both of these new technologies rely heavily on clean oil and specific pressure.
With electronic fuel injection replacing carburetors and becoming much more precise since its wide use began in the 1980’s, engine oil stays much cleaner, which in turn helps engines last longer. Credit also the gasoline manufacturers by designing additive packages that help keep fuel injectors working properly. Most people don’t know that the same detergent that was once only available in “hi test” fuel is now available in all fuel grades. Gone are the days where you would need to run a tank of “hi test”once in a while to clean your engine out.
With a little bit of history known, the old tried and true 3 month or 3,000 mile oil change has come under fire recently. Many manufacturers believe that their engines can go much longer between oil changes, some almost 15,000 miles (yikes!). There are some vehicle manufacturers that have “oil life monitors” built into their vehicle’s electronics. No, there isn’t a little chemistry lab in the oil pan analyzing the engine oil, but rather a complex computer algorithm which calculates (supposedly) when you need to change your oil. This calculation is based on many factors, including how you drive your car, what the temperature is outside, how long you drive your car, your speed, how much time is spent idling, etc.
One of the first extended oil change interval conceived was done by Mobil 1 oil back in the 70’s. They claimed that their new synthetic oil would last 25,000 miles (what could go wrong there??) and they backed that up with a warranty on your engine. Not surprisingly it didn’t take Mobil 1 long to quickly change their policy…
Most new car manufacturers have some sort of extended oil change interval. What many people don’t realize is that it is very vague and has gray areas. While many people mistaken believe they are using their vehicle under “normal” conditions, they are really using their vehicle under “severe” conditions as defined by the manufacturer. For example, some manufacturers might state that under normal usage the engine oil should be changed at 6,000 miles and under severe usage that the oil should be changed at 3,000 miles. The definitions of “normal” and “severe” aren’t able to be clearly defined, and many times the vehicle is operated under BOTH conditions! There is no doubt, however, that cold weather and short trips are the worst scenario for engine oil. Neither the engine nor the oil ever gets hot enough to keep moisture out. Likewise, extremely hot temperatures in the summer causes engine and oil temperatures to spike, which breaks down oil quicker.
So then the obvious question is why do manufacturers recommend extending the oil changes to 5,000, 10,000 or even 15,000 miles? Several reasons come to mind. Without getting into too much political banter, auto manufacturers receive tax credits for “long life” or “extended maintenance items”, for the obvious reason of less pollution created. Gone are the days when belts, hoses, antifreeze, spark plugs, transmission fluid, some filters, etc needed to be changed every 30,000 miles. Manufacturing of millions of gallons of antifreeze, for example, creates a lot of pollution. Technology has provided the solution in these cases. This makes sense, but auto manufacturers have gambled a bit on oil change intervals as well as some other “maintenance-free” items in my opinion. Another reason for advocating extended oil change intervals is to keep the total cost of vehicle ownership down for advertising purposes. Marketing certainly plays a big role here although some people wished that they had their oil changed more often when faced with a major, preventable engine repair. Under certain conditions extending oil change intervals will work out just fine but many people’s driving habits here in Central NY don’t fall under those conditions.
As I mentioned earlier, both engine technology and oil technology has advanced greatly. Part of the new engine technology makes engine oil changes more critical because of the very small passageways, oil screens, oil-dependent actuators, etc, that rely on clean oil and proper oil pressure to operate correctly. Sludge from infrequent oil changes can and will result in costly repairs, far greater than skipping a few oil changes will make up for! In some cases, your ”check engine” light will illuminate because of improper oil viscosity or “worn out oil”, causing reduced performance and increased fuel consumption and increased emissions. In certain cases, your vehicle can fail NY State’s yearly emissions test because of too infrequent of oil changes.
For the vehicles that have oil life monitors, these monitors have several shortcomings. The politics behind them and the lack of accuracy comes to mind. GM had a situation on their 3.6L engines that required the oil life monitor to be reprogrammed to significantly lower the mileage that the oil is supposed to be changed at. The reason was simple – severe engine damage was occurring as a direct result of extended oil changes! This has affected millions of vehicles. Our recommendation and the recommendations of many shop owners across the country is that the oil should be changed at the 50% mark on vehicles with oil life monitors (in most cases) to “play it safe”. With the price of new cars or expensive engine work, it doesn’t make sense to gamble. I will be happy to give my opinion on what I think your oil change interval should be, drawing off of a lifetime of experience of being directly in the auto repair industry for nearly 30 years. It’s kind of ironic that my recommendation will almost always be less than what the manufacturer recommends, since we make no money on oil changes but we do on major engine repairs!
Two other items that are noteworthy with extended oil change intervals are oil consumption and the rest of the vehicle. First, all engines consume a small amount of oil as part of normal operation. An unintended consequence of extended oil change intervals is that oil is burned and not being replaced, leaving the remaining oil to be overworked resulting in premature oil breakdown and sludge build-up. Many Volkswagen 4-cylinder, 4-quart oil capacity engines come to mind here. If the oil change interval is 10,000+ miles according to Volkswagen, and the normal oil consumption is 1 quart per 5,000 miles for example (what, German cars burn oil??), that engine will have about 2 quarts of sludgy oil left at the normal oil change interval. How long can an engine be expected to survive under these conditions? Clearly checking and adding oil periodically would alleviate low oil concerns, but in reality checking one’s oil is a practice abandoned years ago for the most part. The fact is VERY few people ever open their hood anymore to check anything except the windshield washer fluid. Second, the rest of the car usually gets neglected along with the oil level. Keeping tires at proper pressures and rotated, cleaning battery terminals, topping off fluids, lubricating door hinges, hood hinges and latches, and looking for small problems before they become large ones etc, all go hand-in-hand with a complete oil change here at B&H. Our philosophy has always been to error on the side of caution when it comes to oil change intervals. Automobiles and automobile engine repairs have both become very complex and expensive, but our clients who adhere to our philosophy of good old-fashioned service typically enjoy lower overall maintenance and repair bills.
Almost as confusing as when to change your oil is the type of oil to use. There are a wide variety of oil viscosities and types recommend by auto manufacturers now, whereas before the standard 10w-30 was used in about 95% of all applications. Also the wide use of synthetic oils by the manufacturers adds to the confusion. Each manufacturer has specific oil type and viscosity recommendations for their vehicles. We have this information and our position is to adhere to the recommendations of oil type and viscosity set forth by the manufacturers for the same reasons as we do our service interval – the engines are far too complex and costly to be gambling with! We current stock 13 different engine oils in house, which meets the needs of 99% of our clients. There are varying quality levels of oil engine oils too, whether they are conventional, semi-synthetic or full synthetic. We also use only brand-name, high quality oil in your vehicle, typically Mobil and Valvoline. Because of varying degrees of quality and loose regulations, semi-synthetic or full synthetic oils advertised at extremely low prices generally aren’t anywhere near the quality of their premium counterparts, so buyer beware!
Finally, we recycle the used oil generated from oil changes ever since our first oil change. Used oil goes to a recycling facility for a new life, instead of being burned in a waste-oil heating system. Once waste oil is burned, it is gone forever and it takes approximately 7 times the energy to produce one barrel of new oil than it does to recycle and repurpose one barrel of used oil. In our opinion and that of many environmentally-conscious people, burning waste oil is bad for the environment and is best left for large recycling centers to handle. Burning waste oil for heat is a practice from years ago by auto repair shops to try to cut heating costs. Many older auto repair shops are poorly insulated and would cost a fortune to heat by other means and “back in the day”, oil was cheap and there wasn’t a large market for recycling used oil. Things have changed rapidly, and California and New York City have banned waste oil burning for obvious environmental reasons.
If you ever have any questions about oil changes, please stop in, call or email us. We would be happy to answer them!
