Best weight of oil?

I have a '91 Miata and use MOBIL ONE 10W30 for all seasons.

For the cold winters in the Northeast, what weight MOBIL ONE oil should I
use?

http://www.mobil1.com/USA-English/Mo...s/Mobil_1.aspx

Also, what about this newer Extended Performance Mobil One?

http://www.mobil1.com/USA-English/Mo...rformance.aspx

Gary wrote:
> I have a '91 Miata and use MOBIL ONE 10W30 for all seasons.
>
> For the cold winters in the Northeast, what weight MOBIL ONE oil should I
> use?
>
> http://www.mobil1.com/USA-English/Mo...s/Mobil_1.aspx
>
> Also, what about this newer Extended Performance Mobil One?
>
> http://www.mobil1.com/USA-English/Mo...rformance.aspx
>
>
>

Personal opinion only. I change the oil and filter in my '91 at
intervals of 3K - 5K miles. At that sort of frequency synthetic oil,
designed primarily for long intervals, is a serious waste of money. If
I'm putting Mobil in mine I use their "Clean High Mileage" 10W30. I've
used 10W30 of every major brand since the car was new everywhere from
Alaska to Key West and have never had a problem with that weight.

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com

John McGaw > wrote in
:

> Personal opinion only. I change the oil and filter in my '91 at
> intervals of 3K - 5K miles. At that sort of frequency synthetic
> oil, designed primarily for long intervals, is a serious waste of
> money.

Very common mistake, synthetic oil won't last one single mile longer
than dino oil. The biggest problem with oil is contamination, not
breakdown and contamination has nothing to do with the oil, it's
entirely external factors such as blowby, condensation and particulates
in the air.

Your change intervals are correct for either conventional or synthetic
oil, the correct change interval for ANY motor oil is that recommended
by the vehicle manufacturer.

10W30 pour point is higher than that of the 5W30 or 0W30 weight but
given that you are unlikely to encounter conditions harsh enough to
warrant anything lower than a 10 you can use whatever.

5W30 has a lower kinematic viscosity and may produce slightly better
gas mileage. It also leaks more is you have bad seals (in my
experience)

Conversely, if your engine is consuming oil use a higher 40 weight
oil.

Funny thing happened when BMW and other luxo makes started selling
cars with maintenance included, when they pay for oil changes, they
disocvered that with an improved additive formulation you can go a
long ways. The 15000 Mobil One is an attempt to comptete with the
guys from Amsoil, who have been selling extended drain oils, mostly
for the trucking induxtry, for a long time.


On Fri, 24 Mar 2006 18:05:14 GMT, "Gary" >
wrote:

>I have a '91 Miata and use MOBIL ONE 10W30 for all seasons.
>
>For the cold winters in the Northeast, what weight MOBIL ONE oil should I
>use?
>
>http://www.mobil1.com/USA-English/Mo...s/Mobil_1.aspx
>
>Also, what about this newer Extended Performance Mobil One?
>
>http://www.mobil1.com/USA-English/Mo...rformance.aspx
>
>

> Very common mistake, synthetic oil won't last one single mile longer
> than dino oil. The biggest problem with oil is contamination, not
> breakdown and contamination has nothing to do with the oil, it's
> entirely external factors such as blowby, condensation and particulates
> in the air.

very common naysaying, which i personally don't believe.

with top-quality filtration and trips long enough to properly heat the oil,
extended drain synthetics (amsoil in particular) have gone 100k miles (!)
between changes, with periodic oil analysis done to determine when the oil
was truly in need of change.

one datapoint: i have used various synthetics (primarily M1 and amsoil) in
a half-dozen vehicles over nearly a million miles, including a tow vehicle
and a track toy. every one of them got clean filters (primarily amsoil and
OEM) every 5k and clean oil every 10k. not a one burned significant oil
over the life of the vehicle (worst was ~1qt over the 10k OCI). these
included a vw 1.8l I4 (~330k), honda 1.8l (~250k miles) and 2.4l I4s (~30k
so far), a nissan 3.0l V6 (~210k), a mazda 1.8l I4 (45k so far), and a
mitsubishi 3.5l V6 (~90k so far). i generally use 0w-30, and i am in the
southeast where winters are rarely below freezing and summers are primarily
in the 90s. i noticed 3-7% improvements in fuel economy in every vehicle
after moving from dino oil to synthetics *in both engine and drivetrain*
(ie: don't expect much if you just change the engine oil).

don't get me wrong, i don't think it's cheaper...but in combination with
fuel savings, i also don't think it's any more expensive. and you change
the oil less often. and you're (arguably) getting less wear and better
longevity. your choice.

$0.02,

dookie

"dookie" > wrote in
m:

>> Very common mistake, synthetic oil won't last one single mile
>> longer than dino oil. The biggest problem with oil is
>> contamination, not breakdown and contamination has nothing to do
>> with the oil, it's entirely external factors such as blowby,
>> condensation and particulates in the air.
>
> very common naysaying, which i personally don't believe.

You should, it's fact. You'll notice no manufacturer of synthetic
recommends extending the change interval anymore.

<opinions, hogwash and unsupported "data" snipped>

I'm not an oil engineer / expert but I know that there are plenty of them
who would strongly disagree with you on your statement. I believe they would
agree that contaminants are a major factor but disagree that the type of oil
you use does not effect, in any way, the recommended change intervals. I do
have a close friend who's done testing on all this type of thing for Shell
for many many years, I'll see what I can find out from him. There are
definitely several schools of thought.

I tend to figure if you're married to a 3 to 5k change, you are wasting your
money on synthetics. If you do go synthetic, don't try to go forever between
changes, I go about 7k. This way I feel I'm getting at least as good of
protection and I'm only having to change my oil half as often which is no
small thing when you're trying to maintain allot of cars.

Chris
99BBB

"XS11E" > wrote in message
...
> John McGaw > wrote in
> :
>
>> Personal opinion only. I change the oil and filter in my '91 at
>> intervals of 3K - 5K miles. At that sort of frequency synthetic
>> oil, designed primarily for long intervals, is a serious waste of
>> money.
>
> Very common mistake, synthetic oil won't last one single mile longer
> than dino oil. The biggest problem with oil is contamination, not
> breakdown and contamination has nothing to do with the oil, it's
> entirely external factors such as blowby, condensation and particulates
> in the air.
>
> Your change intervals are correct for either conventional or synthetic
> oil, the correct change interval for ANY motor oil is that recommended
> by the vehicle manufacturer.
>
>
>

"Chris D'Agnolo" > wrote in
:

> I'm not an oil engineer / expert but I know that there are plenty
> of them who would strongly disagree with you on your statement.

Start with Ford, GM and Chrysler, all are using synthetics in their
cars, all have not extended the change interval.

What about Mobil 1? They backed off on their extended change
intervals and are now recommending the manufacturer's intervals.

> I tend to figure if you're married to a 3 to 5k change, you are
> wasting your money on synthetics.

Yup. Synthetics have NO "real world" advantages.

> If you do go synthetic, don't try to go forever between changes, I
> go about 7k. This way I feel I'm getting at least as good of
> protection and I'm only having to change my oil half as often
> which is no small thing when you're trying to maintain allot of
> cars.

You'll probably survive with that interval but you're mostly kidding
yourself.... FWIW, I had a customer who brought in a Dodge van, 318
(5.2 liter) V8 that had never had an oil change in 80,000 miles. She
added oil, any kind, any brand, when the oil light went on. She
finally decided to ask about oil changes and I told her she was
overdue(!). We drained out about 1.5 qts of thick, black sludge and
refilled with fresh oil, put on a new filter and.... it ran fine, used
no oil, had good compression, etc. In other words her neglect had done
NO damage to the engine at all. Does that mean it's OK?

"Gary" > wrote in
newsS1Vf.179$Po1.110@trndny01:

> On the subject of oil filter, is there something better than Mazda
> OEM filters that I should consider?

I think the OEM filter is as good as any and probably better than some.
I'd stick with it.

My main objection to using it is that I like being able to get oil and
filters at places I know I'll find when travelling such as Walmart,
Checker, Pep Boys, etc. My fix for that is to carry an extra filter,
it fits in with the jack and lug wrench but if I had to use a Fram, AC,
Motorcraft, etc. filter I wouldn't worry about it.

In article >,
XS11E > wrote:

> Synthetics have NO "real world" advantages.

Well, their smaller, uniformly-sized molecules theoretically offer
better lubrication. Do we need better lubrication? Nope, not if we keep
an eye on the dipstick. High-boost turbo cars might be an exception, due
to heat.

--
Lanny Chambers
'94C, St. Louis
http://www.hummingbirds.net/alignment.html