I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

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"Vic Dura" wrote in message
...
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

Viscosity and lubricating quality are not necessarily related. I can't
recall having a car since the 70's that called for 10w-40. That was a big
V-8 that did not have the tolerances in the newest engines. All others were
10w-30

A lot of the engines made today have tight tolerances, therefore
needing the lighter weight 30. My 2003 Odyssey uses 5W-20 as well.

Vic Dura wrote:
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements?

That is not a reduction in the lubricating requirements. It is an
indication of a less thick oil. Less thick does not convert to less
lubrication.

I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

You are right about the reduced pumping force, but that applies to the
hot measure (large number) as well. It also means the engine has to use
less energy to move pistons and other engine parts all of which mean a
little higher mileage.

It does not stop there. Today's engines are not designed like older
engines. The parts are made with closer tolerances so the heavier oil would
not lube or cool (cooling is a function of oil as well) them as well.

Stick with what the manufacturer recommends. If you want better oil,
try synthetic. Of course be sure to use nothing by synthetic if the
manufacturer calls for it.

The lubrication and other specifications are part of that letter after
the "S" You can use any oil rated equal to the "S" number specified or
higher. ("C" number for diesel engines).

--
Joseph Meehan

Dia duit

Vic Dura wrote:

I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

Others answered the basic questions, I'll just note that for years long
ago, Chevy specified 20-20W in all their truck engines--I've still got
one '58 which has been through every harvest since it was new and has
yet to have any work whatsoever other than normal maintenance. Still
using 20-20W in it...

"Vic Dura" wrote in message
...
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

There is also a subtle consideration or the local ambient temperature range.
Where I am, from now to October we can ecpect day highs about 90 or better
and night lows in the 70's. I have been running 10W-30 in my 92 Explorer
for 174k+ miles with no problems.

Charlie
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What you're missing is that bulk viscosity has little to no relationship to
the lubricating performance in thin films at high contact pressures, and
that the spacings and tolerances are in the bearing are differant/smaller in
the newer engines so a lower visc is required/desired. The lower viscosity
oils do cause lower pumping losses and narrower visc ranges e.g. 5W-20 vs
5W-30 or 10W-30 vs 10W-40 or 10W-50 require less viscosity modifier
additives (which tend to break down over time). So in short, use what is
recommended, though it may seem odd at first.


"Vic Dura" wrote in message
...
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

--
To reply to me directly, remove the CLUTTER from my email address.

On Sun, 19 Jun 2005 06:13:59 -0500, Vic Dura
wrote:

I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

your not missing much... From the other posts use the recommended
oil..

I have a 2001 Saturn that likes to drink oil.. It has 91000 miles on
it.. Bought it new.. uses 1quart every 1000 miles.. Your milage will
very...

The oil change schedule I've followed religously from the day i bought
it new (w/130 miles)..

130-500 Change (5w30)
every 2500 til 50000 (5w-30)
every 2000 til engine dies..(10w-40) Summer, (5w-30) Winter

The 10w-40 has stopped the oil usage by 1/2 quart however
still burns it ...

also check the oil for when it turns black the filter is full and
needs replaced.. (At least my saturn does it on the mile @ 2000)..

I've Penzoil from the 1st oil change and OEM Filters..

....

I've *heard* the focuses minmick the saturn in oil usage.


hope this helps

Joe

wrote in message
I have a 2001 Saturn that likes to drink oil.. It has 91000 miles on
it.. Bought it new.. uses 1quart every 1000 miles.. Your milage will
very...

The oil change schedule I've followed religously from the day i bought
it new (w/130 miles)..

Years ago, that was normal consumption. I have two Buicks with the 3.8
liter. The older one has 142,000 and uses a quart in 3500 miles, the newer
one has 96,000 and does not use a full quart between changes at 7500 miles.
Yes, that is 7500 miles between changes as recommended by GM.

On Mon, 20 Jun 2005 07:39:34 GMT, in alt.home.repair 5w-20
motor oil wrote:

What am I missing?

your not missing much... From the other posts use the recommended
oil..

Thanks for all the comments. I was never considering using anything
other than the recommended oil, I was just curious about why the
change. I didn't know about modern engines being built to closer
tolerances. The lower viscosity spec now makes sense to me.


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In article ,
Vic Dura wrote:
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

--
To reply to me directly, remove the CLUTTER from my email address.

Why does the change in oil specification indicate to you that there is
a reduction in lubricating requirements?


--

Larry Wasserman Baltimore, Maryland

For one thing, the numbers mean very little. Crude approximations at
best. IOW, 10W30 is never as low viscosity as "straight 10" nor as
high-viscosity as "straight 30" per API specs. Conventional mineral
oils slip past this "kludge" and don't do what you'd hope for at high
temps.

Synthetics, OTOH, typically have very little viscosity variation from
below freezing to many hundreds of deg. F. They _were_ developed for
jet engines, with huge temperature variations. Bottom line: just on
the basis of lubricating-film-strength, a 5W20 synthetic will flow at
temps below 0 F (where conventional 10W30 is like butter) and likely
better protect engine innards than 10W40 when you're towing across the
Mojave.

But wait ... synthetics typically reduce viscous drag at ring/bore
interface enough to notably increase fuel mileage. Extreme detergency
is yet another plus. Higher price, but much lower net cost. IMHO.

HTH,
J

On Mon, 20 Jun 2005 12:51:48 GMT, in alt.home.repair 5w-20
motor oil (Lawrence Wasserman) wrote:

In article ,
Vic Dura wrote:
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

--
To reply to me directly, remove the CLUTTER from my email address.

Why does the change in oil specification indicate to you that there is
a reduction in lubricating requirements?

I always thought that the second number e.g. the 20 in 5w-20 indicated
the high temperature lubricating ability of the oil. So for 5w-20 the
oil flows/lubricates like 5w oil when cold and like 20w oil when hot.
Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

--
To reply to me directly, remove the CLUTTER from my email address.

"Vic Dura" wrote in message


Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

Flows like and lubricates like are different things. The lower the number,
the lower the viscosity. This has nothing to do with the ability to
lubricate anything. That is determined by the composition of the oil

Vic Dura wrote:

....
I always thought that the second number e.g. the 20 in 5w-20 indicated
the high temperature lubricating ability of the oil. So for 5w-20 the
oil flows/lubricates like 5w oil when cold and like 20w oil when hot.
Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

Except that it's only the (approximate) viscosity being indicated, not
the lubrication properties. That's specified by the SAE letter
designation (SE, SF, etc.).

On Mon, 20 Jun 2005 15:25:08 -0500, in alt.home.repair 5w-20
motor oil Duane Bozarth wrote:

Vic Dura wrote:

...
I always thought that the second number e.g. the 20 in 5w-20 indicated
the high temperature lubricating ability of the oil. So for 5w-20 the
oil flows/lubricates like 5w oil when cold and like 20w oil when hot.
Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

Except that it's only the (approximate) viscosity being indicated, not
the lubrication properties. That's specified by the SAE letter
designation (SE, SF, etc.).

Ok, thanks for the comments. I think I have a better understanding of
it now.

--
To reply to me directly, remove the CLUTTER from my email address.

In article ,
Vic Dura wrote:
...snipped...

a reduction in lubricating requirements?

I always thought that the second number e.g. the 20 in 5w-20 indicated
the high temperature lubricating ability of the oil. So for 5w-20 the
oil flows/lubricates like 5w oil when cold and like 20w oil when hot.
Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

The numbers are a measure of viscosity. The engine manufacturers
specify the oil viscosity according to the needs of the particular
engine, based on bearing clearances, temperature conditions, testing,
and many other factors. If a higher viscosity was always better we
could run 90-140w gear oil in our engines.

--

Larry Wasserman Baltimore, Maryland

"Vic Dura" wrote in message
...
On Mon, 20 Jun 2005 15:25:08 -0500, in alt.home.repair 5w-20
motor oil Duane Bozarth wrote:

Vic Dura wrote:

...
I always thought that the second number e.g. the 20 in 5w-20 indicated
the high temperature lubricating ability of the oil. So for 5w-20 the
oil flows/lubricates like 5w oil when cold and like 20w oil when hot.
Then going from 10w-40 to 5w-20 would mean that when hot the engine
oil flows/lubricates like 20w oil instead of 40w oil.

Is that correct or am I miss-understanding all of this?

Except that it's only the (approximate) viscosity being indicated, not
the lubrication properties. That's specified by the SAE letter
designation (SE, SF, etc.).

Ok, thanks for the comments. I think I have a better understanding of
it now.

The viscosity measurements are made at 0C (32F) and 100C (212F).

So for 5W20, at 0C the viscosity is the same as straight weight 5 at that
temperature.

At 100C the viscosity is that same as straight weight 20 at 100C.

Still while warming up the 5W20 still thins. It has higher viscosity when
cold than when hot.

I suggest a synthetic because it does not have Viscosity Improvers.

There are some good sites about oil around the web:

http://www.chris-longhurst.com/carbi...oil_bible.html

On Tue, 21 Jun 2005 22:41:37 GMT, in alt.home.repair 5w-20
motor oil "Rich256" wrote:

There are some good sites about oil around the web:

http://www.chris-longhurst.com/carbi...oil_bible.html

Thanks. I'll dial-in and check them latter.

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To reply to me directly, remove the CLUTTER from my email address.

Vic Dura wrote:
I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

thinner the oil, better the gas mileage, I believe

wrote:
I'm still looking for some 1w1000 oil. That should work for anything.

Or nothing. It would be like water when cold and worse than tar when
hot. :-)




On Sun, 19 Jun 2005 06:13:59 -0500, Vic Dura
wrote:

I just bought a new car last month. My previous car was a 1997 model
and it specified 10w-40 motor oil, as had every car I have owned for
the past 30 years. This new car (a 2005 Ford Focus) specifies 5w-20
oil. I've since found out that 5w-20 has been pretty much standard for
the past couple of years.

Question: Why the apparent reduction in lubricating requirements? I
can understand that theoretically the 5w requires less power to pump
and therefor *might* result in some mileage improvement; but the high
temp reduction from 40 equivalent to 20 equivalent doesn't make sense
to me.

What am I missing?

--
Joseph Meehan

Dia duit