switching to synthetic at 100K

[alf]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

thx,

 

[John]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

I just switched at 76K

 

[y_p_w]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

What kind of "synthetic"? I generally accept "synthetic" to be
more of a buzzword once Castrol NA let their marketing dept
loose in the late 90s. I consider most "flavors" of Castrol
Syntec sold in the US to be somewhere between current high
performance "synthetic" oils and current "conventional" oils.
There are others marketing "Group III" base oils as synthetic,
which I consider marketing gone awry.

As long as you've taken good care of your engine, I wouldn't
worry about leaks.

I personally use Mobil 1 5W-30 in my 2004 WRX.

 

[Josh]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

thx,

Not many years ago, I was told to beware switching between regular and
synthetic oils because, if you switched to synthetic you couldn't switch
back to regular ever again. I was told that the oils didn't "mix" and would
ruin my engine. What a load of nonsense. But the above illustrates the point
that there is a lot of misinformation out there on synthetic oils. There is
no evidence that synthetic oil provides any better protection than
conventional oil. It does provide a good deal of piece-of-mind, though. That
could be more important than the extra $$ saved continuing to use
conventional oil.
josh

 

[Carl 1 Lucky Texan]

Not many years ago, I was told to beware switching between regular and
synthetic oils because, if you switched to synthetic you couldn't switch
back to regular ever again. I was told that the oils didn't "mix" and would
ruin my engine. What a load of nonsense. But the above illustrates the point
that there is a lot of misinformation out there on synthetic oils. There is
no evidence that synthetic oil provides any better protection than
conventional oil. It does provide a good deal of piece-of-mind, though. That
could be more important than the extra $$ saved continuing to use
conventional oil.
josh

I think modern engines with modern oils in them can be quite reliable
and experience much greater longevity than in the past. That said,
'synthetic' oils have an edge on 'non-syn' oils in lab tests and oil
analysis in most cases - does it mean you'll get twice the sevice from
an engine? or 2% more? I dunno. I have the means to afford synthetic and
run it in both cars 5-30 in the Outback H6 and 5-40 (Rotella) in the WRX.

www.bobistheoilguy.com has some interesting reading on engine oil.

Carl

 

[Rick Courtright]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

Hi,

There's so much myth about synthetics out there one doesn't know what to
believe. People can't even agree on what IS or ISN'T a TRUE synthetic. I
won't get into that one.

From personal experience, if your engine's not burning oil, and has no
noticeable leaks, the switch will probably go well. IF it's burning oil,
I seriously doubt you'll see an improvement--you'll just be burning more
expensive oil now.

On the leak thing: it's been reported over the years synthetics CAUSE
leaks. Don't think so myself, at least not with today's versions (there
WERE some documented problems at first.) They DO a better job of
cleaning, and CAN dissolve some of the old crud that may be preventing a
leak, though. This varies by engine. Many changes have been made over
the years, both in the oils and seal chemistries to ensure leaks aren't
being caused.

Lots of people report huge gains in fuel economy. Don't think so myself,
based on very extensive fuel records over several cars w/ synthetic and
dino oils. For myself, a gain of no more than about 2% over 10s of 1000s
of miles is all I've seen.

Benefits: if you live in a hot climate (I do), you'll get better
protection and less breakdown of your oil over a given time. This CAN
allow longer change intervals, as long as you're NOT under warranty (so
you're safe!) If you're under warranty, you've gotta change as the book
says regardless of the oil you use.

You may enjoy greater peace of mind, knowing you've done your part to
help your engine. To some, this is very important. To others, it's not.
Oil is one of those "my brand's the only brand" things people love to
argue about and my Mobil 1 buddy can argue until he's blue in the face,
but he won't convince my Castrol GTX neighbor there's any reason to
change!

So try the switch. If you don't notice improvements, yes, you CAN go
back to dino oil and nobody's gonna be the wiser.

Rick

 

[Carl 1 Lucky Texan]

Hi,

There's so much myth about synthetics out there one doesn't know what to
believe. People can't even agree on what IS or ISN'T a TRUE synthetic. I
won't get into that one.

From personal experience, if your engine's not burning oil, and has no
noticeable leaks, the switch will probably go well. IF it's burning oil,
I seriously doubt you'll see an improvement--you'll just be burning more
expensive oil now.

On the leak thing: it's been reported over the years synthetics CAUSE
leaks. Don't think so myself, at least not with today's versions (there
WERE some documented problems at first.) They DO a better job of
cleaning, and CAN dissolve some of the old crud that may be preventing a
leak, though. This varies by engine. Many changes have been made over
the years, both in the oils and seal chemistries to ensure leaks aren't
being caused.

Lots of people report huge gains in fuel economy. Don't think so myself,
based on very extensive fuel records over several cars w/ synthetic and
dino oils. For myself, a gain of no more than about 2% over 10s of 1000s
of miles is all I've seen.

Benefits: if you live in a hot climate (I do), you'll get better
protection and less breakdown of your oil over a given time. This CAN
allow longer change intervals, as long as you're NOT under warranty (so
you're safe!) If you're under warranty, you've gotta change as the book
says regardless of the oil you use.

You may enjoy greater peace of mind, knowing you've done your part to
help your engine. To some, this is very important. To others, it's not.
Oil is one of those "my brand's the only brand" things people love to
argue about and my Mobil 1 buddy can argue until he's blue in the face,
but he won't convince my Castrol GTX neighbor there's any reason to
change!

So try the switch. If you don't notice improvements, yes, you CAN go
back to dino oil and nobody's gonna be the wiser.

Rick

One quick observation - do not be concerned at how incredibly dark the
syn-oil will be when you change it, particularly on a vehicle switched
from 'dino' oil. Syn keeps 'varnish' in soulution/suspension and it's
dark because that is the stuff that otherwise would be coating the
engines internal parts.

Carl

 

[Sheldon]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

thx,

My understanding is that syn oil is great, but if you have any oil leaks the
syn is so good at getting into ever nook and cranny it can make your oil
leaks worse. Otherwise, it just takes a lot more abuse than petroleum based
oils. If you forget an oil change or your car overheats a bit you don't
have to freak out with synthetic.

 

[SilverStude]

switching to synthetic oil at 80-100K miles -can it do any good or bad?

thx,

Switching to Syn-oil is best done right after break-in, around 15-20K.
If you change it at 3-4K mile intervals after that ( with a filter),
your engine will last forever...... At the time you change to it, it
almost puts engine wear into suspended animation...

 

[alf]

an engine? or 2% more? I dunno. I have the means to afford synthetic and
run it in both cars 5-30 in the Outback H6 and 5-40 (Rotella) in the WRX.

Is it that Rotella T Synthetic 5W-40 for diesel engines? Asking
seroisuly since use it for my Yamaha FZ-1 (12K RPM read line) and think
of using it for my Outback too.