Recommended oil viscosity

Yes, that is my understanding also.

I never mentioned anything about 10W-40 oil. Where'd you get that from
in relation to my post above? And 5W-30 IS the recommended viscosity
for most cars made in the last decade or thereabouts so where do you get
the idea that it should be avoided? Have you owned a car newer than 1985?

This is really hilarious. All you need to do is read your owner's
manual or, even easier, read the top of the oil filler cap.

Then you are not following the recommendations of either the maker of
your vehicle or the maker of your oil, which is Mobil, not Mobile, which
I believe is in Alabama.


Matt

 

Yes, lacking any better data I go with the manufacturer's
recommendation. I also use radial tires now rather than bias ply, use
nitrogen filled shocks, and even gave up my 8 track for a CD player!

Matt

 

The "problems" with 10w40 seldom show up if the oil is changed on the
"severe" schedule - which I always do. The spread betweeen high and
low on 20W50 is roughly the same as on 10W40. 3W30 as well. Why is
10W40 more of a problem than either of the others???? The "long chain
hydrocarbon shear problem" is a Boogeyman.

Any "swamp juice" lubricant needs to be changed often enough - and
often enough is generally more often than the mfr spec.
The way my vehicles have historically been driven, I wouldn't trust
5W20 oil to get them to 300,000Km. My vehicles tend to spend a lot
more time running relatively hard at speed than they do being started
cold. Also, proper warmup procedure goes a long ways to giving long
life. Start up, run for half a minute, put in gear and drive gently
untill the temperature guage gets up off the pin. Don't drive hard
until it is in the normal range.

If you want to jump in at -20 and drive like you are Mario Andretti
for 3 miles right from the start, then shut it off - use 5W20 and
trade it in every 2 years like the majority of American drivers do.

When I was a Toyota service manager our dealership used 10W40 and
20W50 oil, and we never (in 10 years) had a single engine failure that
could be in any way attributed to lubrication. No bearing problems,
timing chain problems, camshaft problems, or ring problems PERIOD. We
DID replace numerous timing chains, tensioners, bearings, pistons and
rods(due to wrist pin problems) etc on vehicles maintained by other
dealers using the recommended (not mandated at that time) 5W30 oils
and long drain intervals.

 

10W-40 is a heck of a lot more spread than 20W-50 - you look at the
proportion, not the linear difference. For a 40 warm to be equivalent
spread (amount of unstable additives necessary) to a 20W-50, you'd go
with 15W-40, which is hard to find. But - not a problem - simply mix
10W-30 with 20W-50 and your pretty close. That is in fact what I do
(heavier on the 10W-30 in the winter, heavier on the 20W-50 in the
summer), and mine also gets thinned slightly with a small amount of
cleaning agent.

Exactly. The recommended 7000 mile change interval on the 2.7L is
absolutely not adequate. Another reason I often scoff at the "always do
what the manufacturer recommends" boys.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

Which, if true, would mean that ALL dealers would now be replacing
numerous timing chains, bearings, etc., now that 5W-30 oils are nearly
universally recommended. Since this isn't the case at the dealers that
I frequent, I think you are wrong.


Matt

 

But if you read the owners manual, really READ it, you will find that
probably 80% of the drivers in American drive according to the "severe"
schedule rather than the "normal" schedule. The severe schedule
typically still calls for oil and filter changes every 3-4,000 miles
rather than 7,500+. I agree that it is disingenuous for the car makers
to make the normal driving conditions "severe", but if you read the
manual, the clues are all there. I actually drive about 50% according
to the severe conditions and 50% according to the normal (highway for
me) conditions. I thus split the difference and use 5,000 mile
intervals with Mobil 1 (5W-30 in the winter and 10W-30 in the summer)
and have had no problems with several cars over 100K.

Matt

 

Yes - Schedule B is for oil (but not filter changes) every 3k. *BUT* I
have read first-hand accounts (you're now hearing it second hand) of
dealers who absolutely refused to consider that there is such a thing as
Schedule A driving and refused to honor warranty claims for failures
where the Schedule A maintenance was religiously followed and documented.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

In central Ontario, Schedule "A" driving does not exist. The
temperatures change too much, as well as the humidity. Half the time
the air isn't even fit to breath, much less run an engine. Unless you
are driving, say from Kitchener to Toronto every day, most people
never get more than one good trip in on a change - and the majority
never get their cars warmed up fully unless they are stuck in a
traffic jam. Those who do the T.O. run in rush hour are not doing
highway driving, either. It's 100KM of stop and go.

As far as "religious following" of Schedule "A""- I've seldom seen it.
If someone is going to go 10,000Km on an oil change, they'll often go
12,0000. Those who stick to the 3000 mile/5000km schedule will also
usually stick to 3 months - and many have less than 4000km on in 3
months. Some will go 4 months to get closer to the 5000Km,
particularly in the summer months.

 

My brother's shop is replacing timing chains on 3.8 GMs, and complete
engines on 3.8 Fords quite regularly. Timing chains on SBCs too.
Independent shop.
Most DEALERS never see a customer's car after it's off warranty, and
the chains etc usually last that long. The dealership where I worked
was an anomolly - we serviced more cars more than 3 years old than we
sold. In any given year our "retention rate" was ALWAYS over 100% on a
3 year basis. Target was 70% IIRC, and most dealers did good to hit
50%. The sales department was pretty good, but the service department
was what REALLY sold cars.

 

You have made my point that if there is no such thing as Schedule A,
then why commit fraud by leading people to believe that there is such a
thing - get rid of the Schedule A maintenance schedule and be honest
with people and tell them (in the vehicle documentation) that the
warranty will absolutely be voided if they change the oil at 7000
intervals. To keep Schedule A in the books when there is no intention
of ever considering it is out and out fraud on the public.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

After reading this long and complex thread, I thought I might throw in a few
observations as to where things might be going with engines, oil and change
intervals. I have a 2004 Crossfire. The manual only has ONE oil listed -
Mobil 1 (0W40), no options for other grades or types.

They do not list an oil change interval, as the car has a Flexible Service
Schedule - mainly, the computer will tell you when its time to change the
oil based on how you've been driving the car. It provides a count down (in
miles) to the next due oil change. Do a lot of short run in city driving and
it counts faster than the odometer resulting in more frequent changes, do a
lot of highway crusing and it counts slower. I also monitors the time the
oil has been in the engine as well as the oil level in the engine.

They do have two types of servicing, an A and a B type, but the only
difference is the B type includes a tire rotation. If the computer has you
on a shorter change interval, it will alternate A and B type service since
the tire rotation is more milage based. If your driving is mostly highway
and your on a longer change interval it will put the B type services back to
back.

 

Anything is possible with a dealer, but I'd think a call from your
lawyer referencing the factory documentation would get them off the
dime, as might a call to the zone office.

Matt

 

I just took a glance at my FSM, and the Schedule A maintenance schedule
is descirbed as being for "normal" (their quote marks, not mine) driving
conditions. Like I said - a good lawyer could make hay with that (i.e.,
"Your honor! If normal conditions don't exist, how can you call them
"normal"?").

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

I'm using 5W-30 semi-synthetic from the dealer. A Conoco brand which
seems very good and costs only the same as dinosaur. But it's
different. I burn less oil so it's not the same as dinosaur. Different
pollution but we don't know what yet.

Anyway, I just found out that for most of the life of this vehicle,
close to 200,000 miles, Voyager, it was serviced not with the
recommended 5W-30 but 10W-30. I gather this helped here because it was
used mostly for highway driving at turnpike speeds. Maybe one weight
heavier for lots of highway driving where that is considered more
important than the heavy wear on just starting up the engine? The
engine is quite tight so far, not leaking, not smoking, touch wood,
which I'm told is unusual or others have said not unusual for this 3.0
L V-6 Mitsubishi.

 

If you check the manual you will find that typically both 5W-30 and
10W-30 are recommended for the temperature range that most of us drive
in. I believe that the 10W-30 runs a little higher on the temp scale
and 5W-30 runs a little lower, but the overlap is pretty substantial.
If you drive within the range for 5W-30 then that is usually stated as
being the choice of preference, but that doesn't mean that you can't
also use 10W-30 if within its operating range.

I typically use 5W-30 in the winter and 10W-30 in the summer, but I
don't worry if I my 5,000 mile change interval runs into August as I
believe the range for 5W-30 goes up to 100F and we rarely see that in PA.


Matt

 

Thanks, that helps. I missed the 100 F limit for 5W-30. Guess the end
of the arrow is really the end, duh me. I'm also in PA and although it
rarely gets to 100, we did have high 90's in the past for a few days in
summer. Now with global warming, it seems PA is gettting cooler in the
summer while the other states are heating up. Warmer winters and cooler
summers.

Since I'm using a semi-synthetic, I suspect it's going to be a little
more robust near 100 F, Conoco-Phillips/Kendall. So far it's not the
same as dinosaur 5W-30. Mind you, I'm not saying it's the same as 100%
synthetic, not that I would know but it definitely is smoother and does
not seem to burn up oil as easily. I am not using as much oil as with
10W-30 or 5W-30 dinosaur. The 10W-30 is good down to 0 F and the 5W-30
is good up to 100 Fahrenheit or 38 C. Easy for me to remember that now.
In the past I had used 10W-30 in winter and 10W-40 or such in summer in
older cars.

You're also right about the choices. The manuals clearly state if a
choice, use 5W-30, for the starting "to reduce low temperature cranking
effort" (but not for the 2.5 Liter engine above 0 C. or 32 F.)

Now when I get it together, I should get another analysis from
Blackwell Labs just out of curiosity. Funny how the mechanics get a bit
bent of shape with all the chemistry that comes back. Guess they feel
threatened since they probably never had chemistry. Or as one said, he
did not need lab reports. He has his ears! But I don't have his ears,
as I explained to him so I need the chemistry.

But it's fun to read those lab reports and they are around $20. The
last one said my oil fine given my engine and its mileage but that it
was more like a 5W-30. I suspect the mechanics knew my car preferred
5W-30 in winter and gave me that although I had asked for 10W-30 near
the winter. I do wish they had explained this to me though.

 

That is pretty funny. By the time his ears hear a problem, it is way
too late. Oil analysis can detect problems in the making so that
corrective action can be taken before something fails enough to cause
noise. This isn't so critical in cars as often the cost of an engine
tear-down for a preventive fix costs almost as much as just waiting for
the failure and then fixing it then (especially when you factor in the
extra several thousand miles you may get waiting for complete failure).

However, in other applications such as aircraft, a catastrophic engine
failure can be life threatening and is thus more than just an economic
inconvenience. This is where oil analysis really shines by catching
problems in the making and allowing a preventive repair rather than a
corrective repair.

Matt

 

As the old joke goes: I know the purpose of the propeller on the front
of an airplane is to cool the pilot 'cause if it ever stops you can see
him start to sweat.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')

 

LoL.

DAS

For direct contact replace nospam with schmetterling

 

Here in Las Vegas I use 20 - 50 W oil all the time. Remember in 1,000
miles of driving or so you 20-50W oil thins out to 17-38 and so on....
IF you use 5-30 W oil it thins out even more with 1,000 miles of
driving. Best to get alittle Thicker oil as it will break down when
driving.
Brian Las Vegas , NV