Synthetic vs. Conventional Motor Oil

[btimbit]

Originally Posted by zamler

On the Toyota corporate 4 cylinder and V6 engines the filter is accessed from under the car, that represents millions of cars. What engine has it accessed from the top? (asking I don't know)

But I was talking about the Mazda specifically.

Not sure if you're asking about Toyota specifically, but on the GM 2.2 Ecotec engine (Cavalier, Cobalt, Pontiac G5, Saturn Vue) it's accessed from the top. Canister style Sort of next to the intake manifold, below the intake pipe. Easiest (and cleanest) oil change I'd ever done.

Worst filter location ever that I've experienced is between the Ford 5.4L Triton V8 or the '96-'99 GM 2.2 2200 in the Cavalier/Sunfire.

I love canister and cartridge filters, just so much easier to get off than a conventional one. The 24v VW VR6 BDF engine might the the exception, it was a cartridge too, but the drain plug on the filter cap was made from the softest plastic I'd ever experienced. So if you tried to do the change with the engine warm, you'd strip the torx bit to remove it and would have to skip draining it, take the whole cap off, and have that last litre of oil just burst out the sides. Messy.

[Kaine]

Came in expecting tons of bad advice and I'm actually surprised, not a lot of misinformation.

No need to reiterate most of what has been said, but one point that needs to be stressed for those considering 10k+ oil changes, as was said earlier it's not so much about the oil "wearing out" in that duration, it's the chemicals that wind up in the engine that the oil additives have to bond to. Even top quality oils have a limit on what they can keep clean at which point engine wear begins.

As far as filters go, as someone that has worked in the industry for too many years as well as someone that has been building high performance engines for as long, Wix filters are among the best you can find. Napa gold filters (re-branded Wix) are on average for most vehicles $8-11 dollars and are as good as it gets.

Fram has been garbage for quite a few years now, do NOT ever purchase a Fram filter.

[pylon]

I have always believed to get the maximum benefit out of synthetic, still change it every 5-8000 kms like it is dino oil. VW's Factory suggested maintenance schedule is every 15,000 kms, on cars that require synthetic, but I still do an oil dump and filter every 7500 kms in the middle.

As others have said, regardless of the quality of the lubricant, they still get full of contaminants. The oil is the blood of your car, and the cleaner you keep it, the healthier the car is. The bottom line is, you can spend another $120 - $200 a year, to add years of life to your engine. Even if you don't keep it that long, your will get all of it back when you sell it, because it still runs like a top, and you have a pile of receipts for synthetic oil changes. When I look at used cars or bikes, I won't even consider one that hasn't been maintained on Synthetic lubricants.

[btimbit]

Originally Posted by Kaine

Came in expecting tons of bad advice and I'm actually surprised, not a lot of misinformation.

No need to reiterate most of what has been said, but one point that needs to be stressed for those considering 10k+ oil changes, as was said earlier it's not so much about the oil "wearing out" in that duration, it's the chemicals that wind up in the engine that the oil additives have to bond to. Even top quality oils have a limit on what they can keep clean at which point engine wear begins.

As far as filters go, as someone that has worked in the industry for too many years as well as someone that has been building high performance engines for as long, Wix filters are among the best you can find. Napa gold filters (re-branded Wix) are on average for most vehicles $8-11 dollars and are as good as it gets.

Fram has been garbage for quite a few years now, do NOT ever purchase a Fram filter.

Too add, lots of people claim K&N oil filters are the best too. Most of K&N's oil filters are also made by WIX.
For the price, a Wix filter just can't be beat.

[Bill Bumface]

Originally Posted by zamler

On the Toyota corporate 4 cylinder and V6 engines the filter is accessed from under the car, that represents millions of cars. What engine has it accessed from the top? (asking I don't know)

But I was talking about the Mazda specifically.

Every car I've ever changed with a cartridge has been on top:

Chevy 2.2L and 2.0L
Volvo S40 T5 and 2.5
Audi 4.2L V8
VW 2.0T
VW TDI
BMW all I6 engines E46 and on

[FLAME ENVY]

Originally Posted by pylon

I have always believed to get the maximum benefit out of synthetic, still change it every 5-8000 kms like it is dino oil. VW's Factory suggested maintenance schedule is every 15,000 kms, on cars that require synthetic, but I still do an oil dump and filter every 7500 kms in the middle.

As others have said, regardless of the quality of the lubricant, they still get full of contaminants. The oil is the blood of your car, and the cleaner you keep it, the healthier the car is. The bottom line is, you can spend another $120 - $200 a year, to add years of life to your engine. Even if you don't keep it that long, your will get all of it back when you sell it, because it still runs like a top, and you have a pile of receipts for synthetic oil changes. When I look at used cars or bikes, I won't even consider one that hasn't been maintained on Synthetic lubricants.

Synthetics do not work well in many older vehicles, particularly of European
lineage. Put synthetic in a 1964-1994 911 that has had conventional oil it's whole life and let me know how you make out. That is but one example. Brad Penn makes a superb semi-synthetic that has a great amount of ZDDP which is desirable in older flat tappet motors. It is very popular with Muscle Car and vintage European Car owners. You will find far more older, high performance vehicles with conventional oil, not synthetic however.

[PIMking]

Synthetic oil in an tired motor will start leaking all over the place.

[Dynamic]

Also heArd from a old millwright that these new synthetic oils with detergents will actually clean all the deposits from the inside of a old engine causing the deposits to plug oil galleries and such. I'm not sure if it's true just what I have heard...

[GGG]

Originally Posted by PIMking

Synthetic oil in an tired motor will start leaking all over the place.

Why does this happen? It just doesnt make sense.

Some of the logic I have read is that it is thinner therefore leaks in old seals. This is obviosly false as this is contolled by the viscosity of the oil which is a property you buy not one inherant to dino or synth. In terms of seats and seals being damaged by synth this doesnt make sense either as the oils meet the same API specs.

So is there a reason? Or is this a car myth like not switching back and forth between oil types because your car is used to one type of oil.

[PIMking]

Originally Posted by GGG

Why does this happen? It just doesnt make sense.

Some of the logic I have read is that it is thinner therefore leaks in old seals. This is obviosly false as this is contolled by the viscosity of the oil which is a property you buy not one inherant to dino or synth. In terms of seats and seals being damaged by synth this doesnt make sense either as the oils meet the same API specs.

So is there a reason? Or is this a car myth like not switching back and forth between oil types because your car is used to one type of oil.

It cleans the gunk that builds up over time.

[GoinAllTheWay]

Originally Posted by PIMking

It cleans the gunk that builds up over time.

That's what I've heard as well. Looks like the one I bought has quite a few cleaning agents in it. I think what most people get concerned about is the seals in your engine wear out overtime and the gunk that has been forced into the seals (somewhat replacing them if you will) can be cleaned out. They all seem to advertise "cleans out engine gunk" so you could be washing away what is effectively keeping your engine seals intact.

Agree, may not be the best idea on older engines but newish ones that have no signs of any leaks should be just fine.

Older engines should just go with high mileage regular oil.

[PIMking]

When I rebuilt my engines I always put synthetic in dfterwards

[devel]

I always hear change after 5000 kms, but is there a time limit on synthetic oil? The sticker from the last change said 5k and had a 3 month date reminder sticker.

My car, 09 Subaru Impreza, uses synthetic oil. It's our secondary family car and lately doesn't come close to 5k kms in a whole year. Currently around 2700km driven since the last oil change which was almost a year ago. Should I be getting it changed more regular even though it's not driven very much?

[Muta]

Yeah, I'm curious on this too. Should I be getting regular oil changes (especially with dino vs. synth) if I drive less than 10k a year? I understand the need for conventional changes, but if I put in synth, can I get away with doing it once annually?

[PIMking]

I change my oil (Mobil one 5w-30) in my Nissan versa every 5000 miles which is like 8k km if I'm not mistaken I also use a bigger oil filter off a frontier instead of the versa one. It's about an inch longer giving more filter area to clean the oil better

[PIMking]

Originally Posted by Muta

Yeah, I'm curious on this too. Should I be getting regular oil changes (especially with dino vs. synth) if I drive less than 10k a year? I understand the need for conventional changes, but if I put in synth, can I get away with doing it once annually?

Oil will end up with chemicals in it after being used that can be harmful to bearings. Even if you drive so low miles it would be best to change the oil before you store the vehicle.

[HockeyIlliterate]

Originally Posted by devel

I always hear change after 5000 kms, but is there a time limit on synthetic oil? The sticker from the last change said 5k and had a 3 month date reminder sticker.

My car, 09 Subaru Impreza, uses synthetic oil. It's our secondary family car and lately doesn't come close to 5k kms in a whole year. Currently around 2700km driven since the last oil change which was almost a year ago. Should I be getting it changed more regular even though it's not driven very much?

Yes.

Many fluid changes are based on mileage or a certain period of time, whichever occurs first.

In the case of oil, change it when you hit the applicable mileage or 1 year from the date of the last oil change, if you don't hit the mileage number by the time that the 1-year anniversary rolls around.

[devel]

Originally Posted by HockeyIlliterate

Yes.

Many fluid changes are based on mileage or a certain period of time, whichever occurs first.

In the case of oil, change it when you hit the applicable mileage or 1 year from the date of the last oil change, if you don't hit the mileage number by the time that the 1-year anniversary rolls around.

Thanks for the advice. Figured I'd get it changed at the 1 year mark regardless of kms but thought getting it changed at 800kms just because 3 months was up was a little over the top.

[Bill Bumface]

The only way to actually know is to get an analysis done. There are way too many variables to be able to peg a mileage or a time. A good synthetic can probably go longer than you think. For those of us too lazy, just pick a short-ish interval and you're fine. We short trip our cars a lot which is tough on the oil. I change it every 6 months which is usually about 5-6000km, and I'm sure plenty premature.

[Erick Estrada]

Originally Posted by GGG

Why does this happen? It just doesnt make sense.

Some of the logic I have read is that it is thinner therefore leaks in old seals. This is obviosly false as this is contolled by the viscosity of the oil which is a property you buy not one inherant to dino or synth. In terms of seats and seals being damaged by synth this doesnt make sense either as the oils meet the same API specs.

So is there a reason? Or is this a car myth like not switching back and forth between oil types because your car is used to one type of oil.

In a lot of engines run on dyno oil the only think keeping some of the mating surfaces from leaking is deposits. The molecules of conventional oil come from organic materials and are not uniform in size and there are larger and smaller ones while lab made synthetic oil molecules are of smaller, uniform in size. Larger molecules of conventional oil may block minute leak paths that synthetic oil will clean away and pass through.