What is the proper application for 15w-50 Mobil 1?

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Is there any reason to use Mobil 1 15w-50 in a low mileage engine? (summer use of course)

Is it just an issue of HP and fuel mileage loss or is the oil just too thick for modern engine clearances?

Thanks

[ April 03, 2003, 10:35 PM: Message edited by: Ron-Indy ]
 
quote:

Originally posted by Ron-Indy:
Is there any reason to use Mobil 1 15w-50 in a low mileage engine? (summer use of course)

Is it just an issue of HP and fuel mileage loss or is the oil just too thick for modern engine clearances?

Thanks


Hi,

Mobil 1 15W-50 is a excellent oil. Europeans
think that xW-40 is a little too thin for
summer use and use xW-50 viscosities without
hesitation.

15W-50 has higher HT/HS viscosity than 0W-40.

It's an excellent oil. Use it with confidence,
especially in turbo-charged engines or in
other engines which generate massive torque.

cool.gif


cheers.gif


Jae
 
the clearances in the 5.4L '00 cobra R engine aren't different than regular production. ford factory fills and recommends mobil 1 15w50 for that car.

a friend who pounds his LS1 camaro in open track events uses mobil 1 15w50, since new, and the engine has made more power every time we've dynoed it.

it (or something similar) is probably a good idea in an engine that will see elevated oil temperatures. what's the standard viscosity test, 100 degrees C? why not show us what happens when it's 150 degrees?

of course, my point of view is always motorsports, so ymmv.

-michael
 
quote:

Mobil 1 15W-50 is a excellent oil. Europeans think that xW-40 is a little too thin for summer use and use xW-50 viscosities without
hesitation.

This isn't quite accurate. Take a look at any of the premium European oil company web sites. You'll see very few (if any) Xw50 oils. Xw40 and Xw30 are the predominant synthetic oils.
 
Jae, you said it would be great for engines that make massive torque. Would that include my FI 383 stroker?? I like Mobil products because they are easily accessable and was thinking of doing a 50/50 mix of the 10w-30 and 15w-50. What do you think???
 
I use Mobil 1 15w/50 in my '97 Honda motorcycle because I ride it in long distance rallies (1000+ miles in 24 hours) and the tach generally stays in the 5000-5500 rpm area during those runs. It currently has 45,000 miles on it and I have no problems with the bike. I know this should probably be posted in the MC section, but someone asked...
 
The oil gets changed between 3000-4000 miles. I usually only have to add about 1/4-1/2 qt during that time (sump only holds 3 qts). I plan on a UOA before the oil gets changed again. Oh, just FYI- 45,000 on a '97 aint squat. A friend of mine sold his '96 2 years ago with 86,000 using Mobil 1 15w/50. His current '02 Kawasaki has over 30,000 miles.
 
quote:

Originally posted by Michael SR:
the clearances in the 5.4L '00 cobra R engine aren't different than regular production. ford factory fills and recommends mobil 1 15w50 for that car.

a friend who pounds his LS1 camaro in open track events uses mobil 1 15w50, since new, and the engine has made more power every time we've dynoed it.

it (or something similar) is probably a good idea in an engine that will see elevated oil temperatures. what's the standard viscosity test, 100 degrees C? why not show us what happens when it's 150 degrees?

of course, my point of view is always motorsports, so ymmv.

-michael


It's easy to show what happens at 150 C as that is the standard HTHS (High Temperature High Shear) test protocol, such as ASTM D4683, ASTM D4741, and CEC L-36-A-90.

This test is run at an elevated 150 C versus the standard 100 C. The shear force is most significant as it's defined by a narrow standardized clearance and 10 to the 6th (One million) "shears" per second.

They used to define the HTHS as cSt, same as the standard 100 C viscosity at low shear. To reflect the variables of defined clearance and shear force, the test results are in mPa s. These are functionally equivilant.

The standard viscosity test is the ASTM D445 test. This is run at very low shear and 100 C. There is actually quite a difference in test results, which should illustrate what happens to most oils subjected to these "normal" environments.

I worry about regular Dino Oil as they use a lot of polymeric additives to thicken the oil. Repeated exposure to high shear environments causes the polymers to break down, resulting in a permanent loss of HTHS viscosity.

For a virgin oil, here is the result for Mobil 1 SS 15W-50:

17.4 cSt @ 100 C (ASTM D445)
5.11 m Pa s (Or cSt) @ 150 C (ASTM D4683)

For Mobil 1 0W-40:

14.3 cSt @ 100 C (ASTM D445)
3.6 mPa s @ 150 C (ASTM D4683)

Some cars in light duty use may be quite well protected even with a shear result down to 2 mPa s. Others benefit from a shear of better than 3.5 mPa s. Anything with a turbo had better use an oil of 4 mPa s.

You also have to trade MRV BPT with HTHS. An oil with a very good HTHS will usually have a higher (Poorer) MRV BPT result than an oil with a lower HTHS, all other things equal.

For example, the MRV BPT of Mobil 1 15W-50 is about the same as a good dino 5W-30, -35 F. Mobil 1 0W-30, with a rather thin HTHS, has a MRV BPT of -58 F. It was -36 F this morning at my house, so guess which oil I'm using?

Remember also that some motors are more sensitive to MRV BPT than others. My 2000 GMC Sierra with Vortec 5.3 (Similar to the LS1)seems to be one of those motors.

The oil pump is mounted to the front of the crank, there is a rear-sump oil pan, and a VERY long oil pickup tube. Unless I use Mobil 1 0W-30 in winter, temps colder than 0 F mine makes a knock and clatter.

Please use your best judgement and pick an oil for the intended use and ambient conditions.
 
quote:

For example, the MRV BPT of Mobil 1 15W-50 is about the same as a good dino 5W-30, -35 F. Mobil 1 0W-30, with a rather thin HTHS, has a MRV BPT of -58 F. It was -36 F this morning at my house, so guess which oil I'm using?

Heyjay, isn't the CCS more relevant than MRV and BPT for comparing cold flow properties?
 
Where are you in ON? Where in ON was it -36F (-38C)??? How it felt in your underwear (windchill) doesn't count.
grin.gif


Now to answer the post...

M-1 15-50 can be used:

1. Whenever a car calls for a 15-40 or similar...ie. heavy duty applications eg. diesel M-B's.

2. Vehicles that call for a 50 weight as being acceptable. Usually though, the 15w part precludes use under -20C tops without a block heater.

3. Maximum protection during racing conditions.
 
quote:

Originally posted by toyvwbenz:

quote:

For example, the MRV BPT of Mobil 1 15W-50 is about the same as a good dino 5W-30, -35 F. Mobil 1 0W-30, with a rather thin HTHS, has a MRV BPT of -58 F. It was -36 F this morning at my house, so guess which oil I'm using?

Heyjay, isn't the CCS more relevant than MRV and BPT for comparing cold flow properties?


CCS is Cold Cranking Simulator, which is a rotary vicsometer that measures the resistance to movement in a test oil. It's somewhat redundant: if an oil has a good MRV result, it will ALWAYS have a good CCS result. But, an oil with a good CCS result may have a poor or failing MRV.

As you can imagine, the resistance of cold oil in the connecting rod bearings, crank bearings, lifters, especially the rings, can be quite high. The CCS does NOT measure the resistance in the oil pump itself, which is why an oil pump drive can shear if the oil is really solid.

Cold flow is ONLY measured using the appropriate MRV (Mini Rotary Viscometer) test procedure, which simulates high yield stress at the oil pump inlet and is quite different from cranking friction. Thus the tag of BPT (Borderline Pumping Temperature).

You also want a wide range of MRV results, not just the BPT or "absolute" result. I'm quite angry with Mobil for replacing all their meaningful data with glitzy ad copy.

Esso appears to be far more customer focused. Point your browser to:

http://www.imperialoil.ca/Canada-English/Products/Lubricants/PS_L_EssoAlphaIndex.asp

And check out the Adobe Acrobat documents for Esso XD-3 and for Protec Extra.

I'm quoting from the Esso Lubricants Handbook:

"An oil with yield stress tends to channel at the pump inlet causing flow to cease. The low temperature pumpability limits are 10 degrees below the CCS limits, this is designed to give a safety margin, such that if the engine cranks the oil will always pump ..."

" ... Caution is advised when starting with booster batteries since this could force the engine to start when oil in the crankcase is too thick to flow. The result may be limited lubrication or no lubrication at all in critical areas, resulting in high wear and, ultimately, engine breakdown ..."

"... unlike large diesel equipment, where lubrication is pressurized all the way up to the piston area, many gasoline engines depend on oil splashing ... during cold weather warm-ups, oil may be too heavy to splash all the way up."
 
quote:

Originally posted by Dr. T:
Where are you in ON? Where in ON was it -36F (-38C)??? How it felt in your underwear (windchill) doesn't count.
grin.gif


Now to answer the post...

M-1 15-50 can be used:

1. Whenever a car calls for a 15-40 or similar...ie. heavy duty applications eg. diesel M-B's.

2. Vehicles that call for a 50 weight as being acceptable. Usually though, the 15w part precludes use under -20C tops without a block heater.

3. Maximum protection during racing conditions.


I have one of those Radio Shack indoor/outdoor things with 15 ft of wire for the outdoor temp sensor. I reset it every night and this morning when I hit Recall: -36 F.

I assume you're also from Ontario. Believe it or not, there is more to Ontario than Toronto or Ottawa.

For example, in winter we're usually quite a bit colder than Thunder Bay. Places like Red Lake, Kenora, Dryden, Sioux Lookout, Pickle Lake, and Atikokan also have had similar cold temps.

You probably get The Weather Network on cable. If you have satellite, it's available on Bell ExpressVu and Starchoice: tune in ch 398 on Starchoice.

You can also go to The Weather Network at:

http://www.theweathernetwork.com

Yeah, at those temps your drawers feel awful cold even with a snowsuit on, and the cat refuses to venture outside so you have to scoop the kittybox out. Sure is pretty here in summer though.

I was trying to answer the question that Michael SR asked about tests at higher temps, which is the HTHS. I always like to qualify my answer by warning that one good result, like HTHS, may provide poor results for another test, like MRV.

I also like to warn folks about how a regular Dino oil, especially a 5W-30, has excessive polymeric additives that can experience permanent viscosity loss after repeated exposure to high shear and high temp conditions. That's why I suggested using best judgement, especially for intended use and ambient conditions.

Yes, Mobil 1 15W-50 is great for high perf motors or heavily loaded motors, especially tow vehicles and RV's, in summer.
 
Thank you. That's why I like BITOG: we can share our knowledge and hopefully we all learn as a result.

Detroit has also had its share of nasty winter weather. Hope it warms up soon!
 
quote:

Originally posted by porterdog:
heyjay, thanks for a seriously informative series of posts; I really learned a lot from them.

Ditto!

I've got a few questions:
1) What is MRV?
2) In used oil, does HT/HS value follow viscosity changes?
3) How does mixing two different oils affect both the winter value ("xW- ") & the HT/HS?

Thanks!
 
quote:

Originally posted by heyjay:
Thank you. That's why I like BITOG: we can share our knowledge and hopefully we all learn as a result.


I've definitely enjoyed reading your posts heyjay, and am proud to say you're from the same province as me!
smile.gif
 
quote:

Originally posted by Eiron:

quote:

Originally posted by porterdog:
heyjay, thanks for a seriously informative series of posts; I really learned a lot from them.

Ditto!

I've got a few questions:
1) What is MRV?
2) In used oil, does HT/HS value follow viscosity changes?
3) How does mixing two different oils affect both the winter value ("xW- ") & the HT/HS?

Thanks!


The MRV (Mini Rotary Viscometer) is used soley to determine cold temp pumping capabilities of the test oil in question, it is a "yield" test under low shear conditions. It is defined by the appropriate ASTM 4684 test procedure.

This is in contrast to the CCS (Cold Cranking Simulator) test as defined by the ASTM D5293 test protocol. CCS is a fairly high shear (Ten to the third power or one thousand shears per second)test to mimic the friction encountered as the piston rings are forced to scape along the liner/cylinder wall.

The MRV is a DC electric drive motor with sensitive current monitoring, hooked up to a small test fixture that can be accurately chilled from temps of -18 C (0 F) to -40 C (-40 F). The current required to drive the test fixture is used to derive, with appropriate calculus and other nasty math, a measure of the low temperature FLOW properties.

Empirical testing has determined that a limit of 600 Poise or 60,000 cP (centiPoise)is the "yield" stress at which the vacuum created at the oil pump inlet is no longer capable of drawing oil. The oil tends to cease to slump and just sits there like taffy.

The "absolute" or MRV BPT is run by chilling the test fixture to an absolute 60,000 cP yield, which is not quite as accurate as the careful measurements made to -40 C. I believe the MRV BPT can be run down to -65 F, which is the limit of the chiller.

Depending on the nature of polymeric additives used, and how much used, the HTHS can proportinately track UOA viscosity changes or can even inversely track UOA viscosity changes.

For example, a UOA may uncover slightly higher kinematic testing (ASTM D445) from 12.2 cSt to 13.8 cSt at 100 C. The HTHS (ASTM D4683) may slightly increase from 3.2 mPa s @ 150 C to 3.3 mPa s @ 150 C.

Or, if there are excessive polymeric additives, say in a 5W-30 Dino oil, and excessive blowby, the kinematic testing may uncover a very large increase from 12.2 cSt to 16.8 cSt. Like sludge.

Likewise excessive condensation (Cold weather starting/idling, stop-n-go) tends to cause the polymers to actually separate from the carrier oil. Then you have this sludge of polymer in your sump and a base 5W in yout motor. Coolant contamination will also cause extreme additive separation and nasty sludge.

But that sludge will have poor lubricating properties and the apparent HTHS may have dipped to 2.1 mPa s @ 150 C. It should be apparent that oils can behave much differently in a virgin oil analysis VOA versus a UOA. Only testing can tell you what that change will be. It's a crap shoot.

Mixing is like playing with the Junior Chemistry set: you're in brave uncharted waters. Only VOA and UOA can tell you the results, and you would have to be VERY precise to get repeatable results.

The Chi Square Law tells us that number of samples "n" must be equal to or greater than 324 to have any degree of statistical confidence in such mixing. So I don't "blend" my own oil.

At one time around here, folks used to take 10W and put in up to 10% kerosene to make the oil flow better in extreme cold. That had poor results and often plugged filters.

Actually, the kerosene blend method is now used as a "poor man's" engine flush.
 
quote:

Originally posted by Ron-Indy:
Is there any reason to use Mobil 1 15w-50 in a low mileage engine? (summer use of course)

Is it just an issue of HP and fuel mileage loss or is the oil just too thick for modern engine clearances?

Thanks


I've often wondered what practical use this viscosity is also. Mobil will not recommend a viscosity outside the manufacturer's spec, so that limits this oil to what?--one or two vehicles?

You could say that it's good for some air-cooled motorcycles, but Mobil 1 doesn't recommend it for that purpose either. They have their own special-purpose oil for that.

You could say it's for racing, but not even racers use the stuff. Racers that want to win use thinner oils.

You could say it's for tired, worn-out beaters, but those cars don't use expensive synthetic oil.

Yet any store that sells M1 sells the 15w-50 grade. On the other hand, two major auto manufacturers recommend 20-weight for nearly all their newer cars. Try to find that grade in 5-gallon jugs at WalMart. Try to find that grade just about anywhere.
dunno.gif
 
Hi,
in this country M1 5w-50 is probably still the most popular selling synthetic engine oil and
Castrol's R synthetic 10w-60 would be in the top three sellers here too

No CAFE here( except Coffee sellers ) and no cars running around the place with smoke trails

We probably have the best choice of synthetic engine oils available here after Europe - from 0w-20 FUCHS to Motul, Repsol to Penrite as a 25w-70 and etc!!!!

Our engine makers export everywhere even to NA and Europe so we have a little knowledge too

This country experiences ambient temperatures from about -15C to about 50C

Regards
 
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