I know some oils are "better" than others, especially when specific applications are considered, but let's say you used the same brand, grade, and type of oil in a car over it's lifetime, changing every 5K miles. All other factors being equal, how much will using an expensive, premium brand oil (like Amsoil/Red Line, or even Valvoline R&P/Penzoil UP) extend the life of your engine over using a bargain priced oil like Supertech/Kirkland, assuming API/ISLAC certified full synthetic. Do you think performance improvement is noticeable in most cases? How many more miles will the premium oils give you over the lifetime of the car? I'm thinking that all oils that meet the spec now are very good, and that the difference would not be huge. I know there are no hard answers to these questions, just looking for opinions.
How much difference does oil really make?
- Thread starter mojoe
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Patman
Staff member
There is no easy answer to this question.
The truth is that in some cases a premium oil is overkill but in other cases that premium oil will allow the engine to be much cleaner and retain more of it’s original power and MPG as a result. A lot of high mileage engines using cheaper oil aren’t exactly in the greatest of shape (which is why VRP is managing to clean up the carbon on the rings of many of these engines)
The truth is that in some cases a premium oil is overkill but in other cases that premium oil will allow the engine to be much cleaner and retain more of it’s original power and MPG as a result. A lot of high mileage engines using cheaper oil aren’t exactly in the greatest of shape (which is why VRP is managing to clean up the carbon on the rings of many of these engines)
I've got some oil to sell you and it will meet whatever criteria you have in mind, so long as you give me your money. How would you like to pay me?
I’ve used Amsoil majority of my driving life since 2004. Ive used M1 for a while too. 5500-6500 intervals on my beloved 15 Tacoma 4.0L 137K was with Amsoil XL and I did a few runs at 10K with SS. I’m one who doesn’t push the envelope too far.
100% engine/condition dependent.
It all depends on the application, driving conditions and service intervals.
For instance, on applications where oil consumption is a known-issue, even a top-tier major brand synthetic oil at OEM intervals may not always be enough to prevent oil consumption after the engine has some miles on it.
Anecdotally, in those same applications, reducing the service interval by 50% tends to result in fewer issues.
For instance, on applications where oil consumption is a known-issue, even a top-tier major brand synthetic oil at OEM intervals may not always be enough to prevent oil consumption after the engine has some miles on it.
Anecdotally, in those same applications, reducing the service interval by 50% tends to result in fewer issues.
That looks so clean you can't even tell oil has touched it! Are you sure your oil pump's working?
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Not much if any honestly. Think of it this way I have never not once seen or heard of a car that was kept up with, like you said religious oil changes with properly specified oils, driven normally, and the like, ever go to the scrap yard because of engine failure due to lubrication. Now most people dont change their oil often enough or religiously enough.
If the engine fails its usually due to being ran low on oil. The engine getting dirty from long drain intervals, being driven too hard, tons of short drive cycles with long OCI's. All things no oil would or could ever prevent. Usually cars that are cared for are gotten rid of due to wrecks, wear and tear on other parts like the suspension, rusting out, and the like.
If the engine fails its usually due to being ran low on oil. The engine getting dirty from long drain intervals, being driven too hard, tons of short drive cycles with long OCI's. All things no oil would or could ever prevent. Usually cars that are cared for are gotten rid of due to wrecks, wear and tear on other parts like the suspension, rusting out, and the like.
A vehicle with an engine that has been maintained as the OP describes is probably not going to suffer engine failure as the reason to get rid of the vehicle. I've suspected for years that transmission failures are the reasons most vehicles that are junked for mechanical problems get junked, with engine failures second. Many people are gung-ho about engine oil changes, but don't bother with transmission services or ATF changes.
A secondary problem with engines is people not changing coolant on time or at all.
When I was looking for a used Ranger pickup several years ago, I found several with well over 100,000 miles that had never had a coolant or ATF change. When I would ask the owner about whether the truck had had those services, he would typically look at me as though I had two heads. I didn't walk, but ran, away from those trucks.
A secondary problem with engines is people not changing coolant on time or at all.
When I was looking for a used Ranger pickup several years ago, I found several with well over 100,000 miles that had never had a coolant or ATF change. When I would ask the owner about whether the truck had had those services, he would typically look at me as though I had two heads. I didn't walk, but ran, away from those trucks.
I don't think it matters at all on a normal street driven vehicle. As long as the correct grade/specification and intervals are followed, then the engine will likely outlast the rest of the car.
I use the cheapest oil that meets specification, follow the appropriate interval and enjoy the savings.
Nowhere close to being the first time this has been discussed, perhaps some of these existing threads will answer the question:
I agree with you.
My only qualification is that some manufacturers specify excessively long change intervals. I suspect these are to get you through the warranty period at a reduced cost but will not maximize engine life.
For example the recommended change interval for my BMW (according to its OLM) was +/- 25,000 km. The head mechanic at the dealership took me aside and said that "If you intend to keep the car for the long term you should cut the oil change interval in half." So I did. I changed the oil half way through but didn't update the OLM, which kept the other maintenance items on schedule. It took 5 1/2 liters/quarts and spec'd BMW LL-01 oil (which is all pretty good oil). I kept the car for 18 or 19 years and the engine was still in excellent condition at the end.
I know right. I miss that truck greatly. Too bad it was totaled out due to hail a year ago.That looks so clean you can't even tell oil has touched it! Are you sure your oil pump's working?
Unless the engine in question has a history of oiling problems, sticking rings for example, you should be fine running any properly certified oil to 5000 miles. No need for anything special.
There are a couple primary factors, in order of importance:
1) Duty cycle. This is #1 far and away the single most important factor. How many starts, time at temperature vs cold, high rpm vs low rpm, high load vs low load.
2) Engine design
3) Lubricant service interval
4) Lubricant selection.
Those are in order. So, depending on how you use the engine and what engine it is and how long you keep the oil in service, the lubricant selection might matter quite a bit. I assure you that a Hyundia or Kia turbo driven entirely short trips and with the oil left in for 20k miles will ABSOLUTELY see a difference between a cheap oil and a premium synthetic.
But if you are running a Toyota V8 entirely on the highway with the cruise control set and changing the oil every 5k, then you'd almost never see a difference in wear rates between even a premium synthetic and a basic blend or even mineral oil if the add pack is good. In that use case, any basic API SP spec will suffice.
dnewton3
Staff member
As Hohn explained, there are a lot of factors which play into equipment longevity. If we could control all those variables (difficult to do), we'd find that premium oils don't so much make an engine last longer, as they make the OCI last longer, because premium lubes resist degradation better than lesser cost options.
- 5k mile OCIs in modern engines are very, very unlikely to reveal any disparity in wear rates regardless of the lube used. Any lube meeting the proper specs will suffice.
- 15k miles or longer OCIs are very, very likely going to expose lesser oils as incapable of going the distance, whereas premium ones can easily do this and more and still protect the engine well.
- 5k mile OCIs in modern engines are very, very unlikely to reveal any disparity in wear rates regardless of the lube used. Any lube meeting the proper specs will suffice.
- 15k miles or longer OCIs are very, very likely going to expose lesser oils as incapable of going the distance, whereas premium ones can easily do this and more and still protect the engine well.
You kind of asked a question and also gave an answer! A 5K OCI I would just use Valvoline Restore and Protect.
None. I see Honda's all the time at work with 300.000 plus miles on them all using whatever oil we have for the life of the vehicle and they still run just fine.
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