Extended Oil Change Intervals
This debate has been around for a while now. If you have a car that runs a conventional oil, then chances are the traditional 3,000 mile oil change is still your best friend. With more modern engines and more modern synthetic oils, many manufacturers are beginning to recommend longer and longer intervals between oil changes. Some cars are now supposed to be smart enough to analyze your driving style and adjust the interval between oil changes based on your own driving behavior. The additives in modern oils are supposed to prevent them breaking down from heat, and maintain their ability to lubricate the engine better.
The ideas are pretty neat, and the idea of going longer between oil changes lessens the impact on the environment and on your wallet. Of course, it isn't always that simple.
HPMotors is not a quick oil change shop, and while we can and do perform oil changes, it is mostly for the convenience of the customer who would like it taken care of while they also have their vehicle in the shop for other, more in depth, maintenance. It is not the profit earning part of our business, so we feel our following thoughts, observations, and recommendations come from a genuine car care point-of-view, and not a money making point-of-view.
While the oil change interval continues to increase for some car manufacturers on their new cars, we do not feel it always accurately takes into account the driving habits and conditions of each individual car owner. Even modern computers and sensors designed to account for your driving habits don't always get it right. It is a new, and very imperfect technology. When you combine that with the "not my concern, my car is watching that for me" mentality that the automated monitoring systems and long oil change intervals encourage, it can begin to cause problems.
1) While oil technology has improved, so has the level of stress and function of the oil in modern motors. The tolerances of modern motors is much, much closer and more precise than ever before. This means the lubrication/friction barrier that oil has to create between moving metal parts is even more important, and under greater heat stress. Especially on cold engine start up, when the majority of the oil is sitting in the oil pan before being pumped through the engine, it is important for the remaining oil film left on the engine surfaces to be as clean and thoroughly present as possible.
As oil wears, it begins to hold carbon, moisture, acidic compounds, and other by products of combustion. An engine that sees a regular, thorough heat cycle (such as an extended period of interstate driving to work) will get more mileage out of its oil before these contaminants begin to form in heavy amounts, but they will always form. These products, along with repeated heat load, wear down the oil and its additives.
A vehicle that sees frequent cold starts, stop and go traffic, idling and short trips will much more quickly see deposits, gunk, and other build up in the engine regardless of how modern the oil is and regardless of the manufacturer recommending an oil change at 10,000 miles or more. A cold motor is simply harder on its oil. The gunk and deposits in the engine mean getting lubrication to the motor quickly after cold cranking becomes compromised, and accelerates wear on the motor.
2) The use of oil pressure as a hydraulic force in newer cam timing systems generically referred to as "variable valve timing" or "VVT" has become extremely common place. There are many proprietary names like VTEC, VANOS, VVT-i, MIVEC, S-VT, VarioCam, and many, many others. You may recognize one of those terms as used on your modern car.
These systems are at the heart of what allows modern engines to get better gas mileage while also offering better performance. Accomplishing that involves a complex system of electronic switches routing oil pressure through to particular areas to activate, deactivate, and change characteristics of the motor while it is running. It requires very precise timing, and very precise tolerances.
Many of those oil passages used in modern VVT systems are quite tiny, and require the oil to move through fine mesh filters or other restrictive areas. It has been the observation of HPMotors that these systems are often incredibly sensitive to the cleanliness and condition of the oil. Remember the issue of carbon, moisture, and other combustion by-products that form in oil? Many issues that we see with these VVT systems relate back to dirty oil, clogged passages, and other related issues causing premature failure of VVT system components and related running issues.
3) Forced Induction/Turbocharging is hard on oil. The majority of modern engines have begun combining their complex VVT systems with turbo charging. The reason why is that turbo charging a smaller motor is a great way to achieve better gas mileage and meet modern emissions standards while still being able to produce a motor with impressive performance.
Turbo charging uses a vehicle's exhaust system and exhaust heat to do its job. Adding a turbo to the exhaust stream greatly increases the heat seen in that system. A car without forced induction can see a broad exhaust temperature range, but we'll call it an average of 800 F (425 C) for normal driving down the road. Under wide-open throttle it can even reach even 1,200 F (650 C) or more. That's pretty hot. Turbo charged exhaust temperatures also have a broad range, but its temperature average is still much hotter. Normal driving can see average temperatures of around 1,250 F (675 C), and temperatures of 1,900 F (1050 C) or more under wide open throttle. Much hotter than a car that does not use a turbo.
That temperature load is important because turbos use engine oil to lubricate themselves and some of them also use engine oil to keep themselves cool. This means that your vehicle's engine oil may be seeing heat loads that are very hot, and as we know by now, one of the main purposes of oil is to resist friction and heat. Oil can only do that for so long before it begins to break down and lose it's efficiency. So a turbo charger can lessen the life of engine oil.
4) Modern emissions systems. While modern emissions systems serve a very good purpose, that purpose is not make your engine run better. The emissions system is only there to improve exhaust emissions. One of the ways that modern cars clean up their exhaust is using a system called EGR. Simply put, to clean up exhaust gases, a portion of the exhaust is re-routed back into the motor to be reburned or more thoroughly burned. However, this re-routing of the exhaust gases through the intake and the top of the head can be a dirty process. It also gives the re-routed exhaust gas the chance to combine with oil vapors and the combustion by products in the oil to create sludge in the top of the motor. The more combustion byproducts in the oil, the easier it is to turn into gunk and carbon build up. The gunk and build-up in the top of the head and intake reduces performance in the motor, and is what can clog oil passages or affect other tolerances in the motor.
While this process is unavoidable to some degree, maintaining an intake system and engine oil that are both as clean as possible can help the amount of residue and gunk that form in the engine head and intake manifold.
Here's a quick video of an example of a vehicle that could have used a more regular oil change cycle despite manufacturer recommendations.
The ideas are pretty neat, and the idea of going longer between oil changes lessens the impact on the environment and on your wallet. Of course, it isn't always that simple.
HPMotors is not a quick oil change shop, and while we can and do perform oil changes, it is mostly for the convenience of the customer who would like it taken care of while they also have their vehicle in the shop for other, more in depth, maintenance. It is not the profit earning part of our business, so we feel our following thoughts, observations, and recommendations come from a genuine car care point-of-view, and not a money making point-of-view.
While the oil change interval continues to increase for some car manufacturers on their new cars, we do not feel it always accurately takes into account the driving habits and conditions of each individual car owner. Even modern computers and sensors designed to account for your driving habits don't always get it right. It is a new, and very imperfect technology. When you combine that with the "not my concern, my car is watching that for me" mentality that the automated monitoring systems and long oil change intervals encourage, it can begin to cause problems.
1) While oil technology has improved, so has the level of stress and function of the oil in modern motors. The tolerances of modern motors is much, much closer and more precise than ever before. This means the lubrication/friction barrier that oil has to create between moving metal parts is even more important, and under greater heat stress. Especially on cold engine start up, when the majority of the oil is sitting in the oil pan before being pumped through the engine, it is important for the remaining oil film left on the engine surfaces to be as clean and thoroughly present as possible.
As oil wears, it begins to hold carbon, moisture, acidic compounds, and other by products of combustion. An engine that sees a regular, thorough heat cycle (such as an extended period of interstate driving to work) will get more mileage out of its oil before these contaminants begin to form in heavy amounts, but they will always form. These products, along with repeated heat load, wear down the oil and its additives.
A vehicle that sees frequent cold starts, stop and go traffic, idling and short trips will much more quickly see deposits, gunk, and other build up in the engine regardless of how modern the oil is and regardless of the manufacturer recommending an oil change at 10,000 miles or more. A cold motor is simply harder on its oil. The gunk and deposits in the engine mean getting lubrication to the motor quickly after cold cranking becomes compromised, and accelerates wear on the motor.
2) The use of oil pressure as a hydraulic force in newer cam timing systems generically referred to as "variable valve timing" or "VVT" has become extremely common place. There are many proprietary names like VTEC, VANOS, VVT-i, MIVEC, S-VT, VarioCam, and many, many others. You may recognize one of those terms as used on your modern car.
These systems are at the heart of what allows modern engines to get better gas mileage while also offering better performance. Accomplishing that involves a complex system of electronic switches routing oil pressure through to particular areas to activate, deactivate, and change characteristics of the motor while it is running. It requires very precise timing, and very precise tolerances.
Many of those oil passages used in modern VVT systems are quite tiny, and require the oil to move through fine mesh filters or other restrictive areas. It has been the observation of HPMotors that these systems are often incredibly sensitive to the cleanliness and condition of the oil. Remember the issue of carbon, moisture, and other combustion by-products that form in oil? Many issues that we see with these VVT systems relate back to dirty oil, clogged passages, and other related issues causing premature failure of VVT system components and related running issues.
3) Forced Induction/Turbocharging is hard on oil. The majority of modern engines have begun combining their complex VVT systems with turbo charging. The reason why is that turbo charging a smaller motor is a great way to achieve better gas mileage and meet modern emissions standards while still being able to produce a motor with impressive performance.
Turbo charging uses a vehicle's exhaust system and exhaust heat to do its job. Adding a turbo to the exhaust stream greatly increases the heat seen in that system. A car without forced induction can see a broad exhaust temperature range, but we'll call it an average of 800 F (425 C) for normal driving down the road. Under wide-open throttle it can even reach even 1,200 F (650 C) or more. That's pretty hot. Turbo charged exhaust temperatures also have a broad range, but its temperature average is still much hotter. Normal driving can see average temperatures of around 1,250 F (675 C), and temperatures of 1,900 F (1050 C) or more under wide open throttle. Much hotter than a car that does not use a turbo.
That temperature load is important because turbos use engine oil to lubricate themselves and some of them also use engine oil to keep themselves cool. This means that your vehicle's engine oil may be seeing heat loads that are very hot, and as we know by now, one of the main purposes of oil is to resist friction and heat. Oil can only do that for so long before it begins to break down and lose it's efficiency. So a turbo charger can lessen the life of engine oil.
4) Modern emissions systems. While modern emissions systems serve a very good purpose, that purpose is not make your engine run better. The emissions system is only there to improve exhaust emissions. One of the ways that modern cars clean up their exhaust is using a system called EGR. Simply put, to clean up exhaust gases, a portion of the exhaust is re-routed back into the motor to be reburned or more thoroughly burned. However, this re-routing of the exhaust gases through the intake and the top of the head can be a dirty process. It also gives the re-routed exhaust gas the chance to combine with oil vapors and the combustion by products in the oil to create sludge in the top of the motor. The more combustion byproducts in the oil, the easier it is to turn into gunk and carbon build up. The gunk and build-up in the top of the head and intake reduces performance in the motor, and is what can clog oil passages or affect other tolerances in the motor.
While this process is unavoidable to some degree, maintaining an intake system and engine oil that are both as clean as possible can help the amount of residue and gunk that form in the engine head and intake manifold.
Here's a quick video of an example of a vehicle that could have used a more regular oil change cycle despite manufacturer recommendations.
So, what should you take away from all this?
1) You should talk to your mechanic about your specific driving habits, and what your vehicle needs may be based off of those habits. Not the person at the quick oil change place that you take your car to on your lunch break, but your actual mechanic you use for the real maintenance work. If you have many frequent short trips on your vehicle every week, or you have a modern turbo charged car and enjoy driving it in a spirited manner/lots of hard acceleration, you may find that they recommend an oil change interval that is significantly lower than the average manufacturer mileage recommendation. Even if you are a driver that puts a thorough heat cycle into their motor every day, you may still find that your mechanic recommends not waiting a full 10-15,000 miles between oil changes. If this mechanic specializes in your brand of car, and you trust them, and they aren't a quick lube place that makes their money off of oil changes, then it may be worth considering their advice.
2) Modern motors, and specifically modern turbo charged motors, are complex and demanding on their synthetic oils. While the cars can go longer between oil changes, it is also important to remember that it's due to a superior oil and superior filter. This means that if you wait the maximum mileage before an oil change and go to a budget, quick lube oil change place that uses cheap oils and filters, you're burning the candle at both ends. You're paying for a compromised product, and therefore you should expect the longevity and performance of the vehicle to become compromised. If you plan to keep the vehicle over many miles and also want to maintain good performance and reliability, it is strongly recommended that you use a good quality oil that meets factory specifications along with a good quality oil filter. If you're not sure what to get, stick with the factory recommended oil and filter.
3) The vehicle owner (you) still has to be involved in caring for and monitoring their vehicle. While a lot of cars will tell you what percentage of "oil life" your car has left, or even a sensor to tell you whether or not your car needs the oil topped off, nothing beats lifting the hood and verifying that information yourself. Being honest about how hard you drive your car, and what type of driving your car mostly sees is equally important.
Adjusting your vehicle's maintenance schedule to your driving habits and taking 5 minutes to check the level and condition of your engine oil on the dipstick two or three times a week can save you a lot of heartburn and expensive engine repairs down the road.
While the days of the 3,000 mile oil change (for modern cars designed with synthetic oils) is fading away, it is not gone. We do have a few customers that still need an oil change interval between 3,000 and 5,000 miles on their modern car because it is mostly a short trip, stop-and-go traffic vehicle. Someone who does extensive interstate driving for business may do well to consider a filter change at 4,000 miles and a complete oil change at 8,000-9,000 miles. The average synthetic oil life we see would still lie somewhere between 5,000 and 7,000 miles in our opinion. This is typically seen in a car that sees a good mix of steady interstate commuting, combined with some stop and go traffic.
The claims of 10,000-15,000 mile oil changes for the average car with the average driving load still seem optimistic at best.
1) You should talk to your mechanic about your specific driving habits, and what your vehicle needs may be based off of those habits. Not the person at the quick oil change place that you take your car to on your lunch break, but your actual mechanic you use for the real maintenance work. If you have many frequent short trips on your vehicle every week, or you have a modern turbo charged car and enjoy driving it in a spirited manner/lots of hard acceleration, you may find that they recommend an oil change interval that is significantly lower than the average manufacturer mileage recommendation. Even if you are a driver that puts a thorough heat cycle into their motor every day, you may still find that your mechanic recommends not waiting a full 10-15,000 miles between oil changes. If this mechanic specializes in your brand of car, and you trust them, and they aren't a quick lube place that makes their money off of oil changes, then it may be worth considering their advice.
2) Modern motors, and specifically modern turbo charged motors, are complex and demanding on their synthetic oils. While the cars can go longer between oil changes, it is also important to remember that it's due to a superior oil and superior filter. This means that if you wait the maximum mileage before an oil change and go to a budget, quick lube oil change place that uses cheap oils and filters, you're burning the candle at both ends. You're paying for a compromised product, and therefore you should expect the longevity and performance of the vehicle to become compromised. If you plan to keep the vehicle over many miles and also want to maintain good performance and reliability, it is strongly recommended that you use a good quality oil that meets factory specifications along with a good quality oil filter. If you're not sure what to get, stick with the factory recommended oil and filter.
3) The vehicle owner (you) still has to be involved in caring for and monitoring their vehicle. While a lot of cars will tell you what percentage of "oil life" your car has left, or even a sensor to tell you whether or not your car needs the oil topped off, nothing beats lifting the hood and verifying that information yourself. Being honest about how hard you drive your car, and what type of driving your car mostly sees is equally important.
Adjusting your vehicle's maintenance schedule to your driving habits and taking 5 minutes to check the level and condition of your engine oil on the dipstick two or three times a week can save you a lot of heartburn and expensive engine repairs down the road.
While the days of the 3,000 mile oil change (for modern cars designed with synthetic oils) is fading away, it is not gone. We do have a few customers that still need an oil change interval between 3,000 and 5,000 miles on their modern car because it is mostly a short trip, stop-and-go traffic vehicle. Someone who does extensive interstate driving for business may do well to consider a filter change at 4,000 miles and a complete oil change at 8,000-9,000 miles. The average synthetic oil life we see would still lie somewhere between 5,000 and 7,000 miles in our opinion. This is typically seen in a car that sees a good mix of steady interstate commuting, combined with some stop and go traffic.
The claims of 10,000-15,000 mile oil changes for the average car with the average driving load still seem optimistic at best.
