How much difference does oil really make?

[Glenda W.]

Actually imagine a taxi fleet under severe service 5k oci’s going to 20k+ oci’s with HPL. Saved money on oil, services, mechanics, downtime etc. I believe fleets are one of HPL’s biggest customers because it saves money for them.

 

[Carlostrece]

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.

Probably not much difference over life of vehicle a suitable grade (viscosity) with proper certication oil is used for the vehicle. However, that's assuming no adverse conditions happen.

i.e. - any brand is fine if it's properly certified oil that's proper grade/viscosity oil and changed at appropriate interval for the vehicle and conditions. Assuming if climate is not severe. Also if there's never a cooling system failure (such as a radiator hose suddenly bursts) while driving in traffic where you can't immediately pull over. Also, if you're not frequently racing around harder than normal.

My Jeep 4L had a radiator hose pop off the radiator (a hose clamp hadn't been tightened) when I was in heavy traffic. I had to keep driving a few more blocks to get out of traffic and safely pull into a Walmart. It was a hot summer day in the 90s too. No harm was done to my engine. I don't know if using a namebrand synthetic oil (Mobil One 10w30) saved my engine, or maybe it would have been fine anyway. Not sure. However, fiascos can happen unexpectedly and a better oil provides some extra protection.

I do think there's benefits from using a synthetic oil compared to a connventional oil in an older car (as long as it doesn't leak or burn oil). Most newer cars require synthetic. Brand probably doesn't matter in normal conditions, but you can't know if/when an abnormally harsh condition might occur.

I think of cheap oil as good enough for most situations, and better oil as cheap good insurance for unexpected situations.

The issue then becomes how much insurance do I want to pay for? I limit my quest for better motor oil to choosing from what I can buy online from Wallyworld. I think the better oils sold by Walmart online are plenty good enough insurance for me and are affordable.

That Jeep I mentioned drove to 93K miles using Mobil One 10w30. Then to 410K miles using Supertech 10w30. Most of that in very hot climates (NV, AZ, CA). It was offroaded a lot and a lot of city miles in it's first 93K miles. Then a lot of highway miles from 93K-410K miles.

Supertech 5w30 is not an oil I'd consider as providing extra protection, but it was good enough. For that matter, I'm not sure I'd consider M1 10w30 as providing extra protection either. Yet the Jeep went 410K even after overheating once.

 

[Carlostrece]

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)

Agreed. However, I know for a fact that people who buy the cheapest oil they can find are often (not always) people who don't care much about their car. Those are usually the same people who buy the cheapest oil filter they can. They also buy the cheapest air filter, if they ever replace their air filter. Often they don't replace the air filter until the engine is in crises.

Those are often the same people who don't change motor oil on time, nor air filter, nor anything other maintenance.

So are their cars wearing out faster from choosing cheap oil and filter, or from not doing maintenance ontime, if ever?

People who buy expensive oil and filters are likely to be meticulous about maintenance. Do their cars last longer due to better oil & filter, or due to having a reliable maintenance schedule?

A cheap oil with good filter combo can give good results if a proper maintenance schedule is reliably followed.

Even a cheap oil with cheap filter combo can be adequate with adequate maintenance schedule. My friend's Jeep 4L went 410K miles doing this driving around NV, AZ, CA.

I like to use medium tier for oil and top tier filter with adequate maintenance schedule.

 

[SubieRubyRoo]

Please, explain why running a boutique in a commuter is throwing away money.

Exactly. @DirectRejection is probably BITOG’s ultimate commuter if he’s still on the pace he described in his 30k OCI threads. Without HPL he’d be doing like 3 oil changes per month! Just think of all that waste oil he’s saving the planet from.

 

[SubieRubyRoo]

While I can appreciate that some boutique oils use high grade base stock, that won't shear out of grade as fast as some cheaper oils, holding grade is only one requirement for engine oil. With DI engines that dilute their oil with fuel, stable viscosity oil is going to waste if you have to change it to remove fuel. And short trippers, what accumulate condensation in the oil should change every year regardless of low mileage.

No doubt, there are some good use cases for high mileage boutique oils, that doesn't mean they will benefit everyone.

Just like EVs have use cases where they may make more sense than an ICE (I.e. inner-city, or <50 mi radius from home on 90% of drives), nobody here is suggesting it would have been a good idea to slap HPL in my Grandma’s ‘91 Lumina that had a grand total of 6,400 miles when she passed in 2008.

But on the flipside, if someone has a need for longer OCIs or greater protection levels, there ARE alternatives to being stuck with “almost good enough”. The right oil for the use case is the happy medium, and it doesn’t just mean high mileage cars either.

 

[cheesepuffs2]

Would you rather have an oil that just barely squeaks by or an oil that greatly exceeds the requirements? Or better still, an oil that has many different European manufacturers approvals. I know what I’m choosing…

How can you be so sure that they "barely squeak by" and didn't just choose to forgo extra approvals due to cost versus return on investment for their market segment?

 

[cheesepuffs2]

That's not how I interpreted that video. I thought it was very informative.

He showed how thick oil doesn't necessarily protect the engine better, and can cause extra drag. Basically, the oil needs enough film strength to eliminate metal to metal contact, and any extra viscosity above this point causes needless drag and provides no functional advantage.

There's a phrase in the lubrication industry, "As thick as necessary, as thin as possible".