Mobil 1 15-50

[Larrymcc]

Myself and friends have been using Mobil 1 15-50 in our late model Harley Davidson. However, lately I have been advised that Mobil has changed the formula for the 15-50 and it no longer meets the criterial for a Harley oil. I would appreciate and info concerning this issue.

 

[ammolab]

Whom ever gave this advice didn't explain WHY it is no longer suitable...or just what the changes are to the oil?

 

[alarmguy]

Originally Posted by Larrymcc
Myself and friends have been using Mobil 1 15-50 in our late model Harley Davidson. However, lately I have been advised that Mobil has changed the formula for the 15-50 and it no longer meets the criterial for a Harley oil. I would appreciate and info concerning this issue.


You do not give the year or model of your bike, so impossible to comment.
Safe to say, all Harley touring bikes made after 2013 require a C rated diesel oil if not using Harley oil but whatever, most people pay no attention to it anyway. (except me of course) )

So, if your one to not pay attention to your owners manual, then Mobile 1 15/50 will be almost as good as any other gasoline oil./ or any brand 20/50.

 

[Onetor]

What does your Owner's Manual require?

 

[Cujet]

Mobil 1 15W-50
SAE Grade 15W-50
Viscosity @ 100ºC, cSt (ASTM D445) 18
Viscosity, @ 40ºC, cSt (ASTM D445) 125
Viscosity Index 160
Sulfated Ash, wt% (ASTM D874) 1.21
HTHS Viscosity, mPa•s @ 150ºC (ASTM D4683) 4.5
Pour Point, ºC (ASTM D97) -39
Flash Point, ºC (ASTM D92) 232
Density @15.6º C g/ml ASTM D4052) 0.87


If the specs have changed, it's not by much and it certainly has not decreased in quality. M1, 15W-50 remains an extremely robust oil, with a 4.5 HTHS (fantastic for high temperatures) and 1200ppm ZDDP (Ideal) . Also with a pour point of -39, it's clearly not a "dino" oil. M1 15W-50 is excellent in high temperature applications.

 

[MoreCowbellAz]

We see occasional vague comments thrown around here that the formula for Mobil 1 15w50 has changed, not as robust as it used to be, no longer suitable for a Harley, etc, but I have yet to see someone give any actual specs as to what's allegedly deficient now. I'd sincerely like to know, when I look at the specs all seems good for a tough oil that should work in a Harley design. I've been using it in my '00 RK for quite some time now, like maybe 4-5 oil changes, so I'd really love to know what people are talking about. My guess is there's nothing behind it, but admittedly I have no idea.

 

[Bonz]

M1 15W50 far right column in this thread from 2014... shared sump engine ZRX1200, just over 4,000 miles. Sheared down a good bit.

https://www.bobistheoilguy.com/foru...1200-mobil-1-10w40-4t-racing#Post4865603

-Mobil says 1300 ppm Z, 1200 ppm Phos. Not sure why so low on those in the UOA (1013 Z, 889 P)


M1 10w40 4T Racing MC specific oil far left column, same ZRX 1200. Held up well in terms of shearing.

-Mobil says 1200 Z, 1100 P and pretty close to those numbers after 4600 miles (1155 Z, 1007 P)

IF the claims for Z/P are held as accurate more or less in the virgin oil, does this mean the Z/P was sacrificial with respect to the 15W50? Or "just one of those things", per se?

 

[Overfill]

I didn't know Harley motors shear oil?

 

[Bonz]

Harley's don't shear, per se, with a non-shared sump, and I don't think I said they did. Wasn't implying that, apologies if it was taken that way.

I was speaking to the 15w50 formulation and the low ppm of Z and P of my used sample where it (should have) started at 1300 ppm Z and 1200 ppm P based on Mobil literature. Only bringing in the 10w40 4T MC specific oil because it was much more in line with what Mobil says it should be based on literature after use in my bike, and wasn't much less in terms of retained viscosity after more miles vs the 15w50 M1.

Wouldn't run a 10w40 in a Harley, no way. 20w50 seems to be the way to go, 15w50 has good results in a Harley and wouldn't see any issue with it based on UOA's.

Just using this as an opportunity to show how the 15w50 did vs the 10w40 and wonder out loud if the low Z/P was maybe an anomaly, or if the 15w50 in my engine needed to "use" the Z/P sacrificially in a shared sump with higher rpm 16v overhead cam engine.

 

[alarmguy]

Originally Posted by Bonz
M1 15W50 far right column in this thread from 2014... shared sump engine ZRX1200, just over 4,000 miles. Sheared down a good bit.

https://www.bobistheoilguy.com/foru...1200-mobil-1-10w40-4t-racing#Post4865603

...



Good post and interesting too.
The 15/50 sheared down a good bit but in your case to a 40, if your good with a 40 weight oil as you have used 10 and 15/40 in your other OCIs, the 15/50 gave you great wear numbers. To me, in a quick glance based on mileage, they look like the best wear numbers. Without changing the subject, when talking 50 to 40 or 40 to 30 types of shearing Im not as concerned as actual wear numbers, because its not only about shearing, its about film strength and I think why modern automobiles/trucks can now go down to 0/20 oils, unheard of decades ago.,.

So it ended up as a 40 but your good with 40 anyway.

I was never a proponent of the M1 15/50 but I can clearly see in cases where a API "S" oil can be used the M1 maybe hard to beat value wise. Heck I would even be tempted to use it for fun and send it off to Blackstone if I didnt need a "C" rated and even then, maybe if I wasnt in such a hot climate.

Oils are far more complicated then the EXTREMELY few components that are tested for in a lab when we do VOAs and UOAs.

Even though UOAs are fun ... (and even I am waiting for my UOA from Blackstone that I sent out last Saturday, still not done. on a C rated semi syn 15/50 which I have been using almost since the bike was new.) its impossible to predict actual engine wear based on looking at the reports and how much an oil might have sheared but in a shared sump, it s**cks when oil shears down and shifting gets notchy, been there, done that on past metrics I owned. I always found conventional oils provided best shifting on those bikes,

 

[BigCahuna]

There's lots of guys that use Mobil 1 15/50 oil without issues. There's a guy on u tube that had over 450k miles on his Harley using that oil. He said he would usually run it longer then what Harley recommend for oci's. Most guys worry about using the most popular/ expensive oil out there today. History of motorcycling has taught us they don't make any motor last any longer. And the fact most guys won't keep bikes long enough to justify the expense of using expensive oils, and doing UOA's. I mean, if a uoa say you have high iron in your oil ,but it seems to be running fine, are you really going to tear it down for an inspection or rebuild?. I doubt it. You might throw it up for sale before something fails, and let the next owner deal with it. Look back in the archives of uoa's and list the different brands of oils people used, any of them seem to do the job . Getting hung up on any certain brand is marketing. Use what you like and spend the least amount for it you can. If you are only keeping your bike for less then 150k miles, don't worry about who makes it.,,,

 

[Bonz]

alarmguy, the aluminum is higher with this OCI (IMO) due to new pistons being installed 150 miles before this oil (M1 10w40 4T) was put in the engine. The iron is up slightly in ppm when looked at from the total miles on the OCI vs 15W50 M1. With that said the engine was taken down to put in new pistons and put back together with new rings, cams removed and reinstalled and re-acquainted with the rocker arms, valves adjusted and a few shims swapped. Maybe the combination of that work raised the iron levels.

Good point that while 15w50 went down to a 40 wt, it would now be solidly in the 40 Wt category vs the 10w40 4T.

Sorry for the hi-jack, the 15W50 is a good oil that, even more so in a non-shared sump, should do as well as the boutique oils for protection.

 

[DoubleWasp]

The talk about 15/50 having degraded in quality compared to the old "red cap" formula was mostly due to experience by engine builders and racers. M1 15/50 turned into a real shear monster that let engines down where it previously had not. Red-Cap was a serious contender oil as street-and-racing oil. We haven't seen a lot of M1 15/50 fills lately, but we routinely fixed low oil pressure complaints by replacing fills of M1 15/50 for VR1 or Schaeffers in the same grade.

The "problems" never really manifested themselves in "normal" engines. It is when running a seriously high performance engine at the edge that Red-Cap 15/50 succeeded, and the new formula failed. There used to be a LOT of guys running Red-Cap M1 in racing and serious builds, and now M1 15/50 never even really comes up in discussion at all. VR1, Schaeffers, Brad Penn, and Joe Gibbs have completely pushed out M1. Or it might be more accurate to say M1 pushed itself out.

Why? Where's the proof in the specs? Who the heck knows? Something that doesn't become tangible in the specs. M1 isn't a superior racing oil despite its stout specs probably for the same reason why VR1 is an amazing racing oil, despite it's mediocre specs.

For most reasonable applications, it will probably never be an issue, though.

 

[loneryder]

Mobil 1 15-50 is now an "sn" rated oil. Didn't that require them to lower the zinc and phosphorus?

 

[RooflessVW]

Originally Posted by loneryder
Mobil 1 15-50 is now an "sn" rated oil. Didn't that require them to lower the zinc and phosphorus?

Not in a 50.

 

[Bonz]

Exactly. The 5/10w30 weights to rate SN. Any weights above that (Xw40, Xw50) to my knowledge can have higher phosphorus and meet other SN requirements and still be labeled SN.

Mobil 1 0w40 is a fantastic oil, SN rated with 1000 ppm phosphorus and 1100 ppm zinc. For Colorado winters at 0 deg F and below a number of times a year, and Colorado summers that get as hot as the Midwest (with hotter engine temps in stop and go because thin air at elevation can't carry away heat as quickly as from the radiator, double so with the A/C running) this oil covers the range very well, and it has a very good additive package. Run it in the 3.7L Acura TL SH AWD and Nissan Juke 1.6L Turbo.

If folks would look at the oil recommendations for their specific vehicle in other parts of the world where mechanically it's the same engine, they would see no one else has a love affair with the light weight oil's as much as the United States of America, due to CAFE standards which is fairly well known.

 

[Overfill]

wait, then why isn't Rotella T4, T5, and T6 also rated SN / SN+ now?
And why did they back off the phos in other CK4 HDEO that are SN rated? delo, delvac, castrol, st, ect..

 

[Bonz]

Shell is making some Rotella oils now that are "multi vehicle" which may be in-line with SN standards for passenger cars and trucks, and keeping their traditional HDEO oils made with relatively higher amounts of Z and P. That's just a guess on my part. Anyone else want to weigh in?

 

[jeff78]

Originally Posted by Brian553
wait, then why isn't Rotella T4, T5, and T6 also rated SN / SN+ now?
And why did they back off the phos in other CK4 HDEO that are SN rated? delo, delvac, castrol, st, ect..


This thread has the answer, in particular the post by Solarent:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4373868/API_CK-4_Phosphorous_Issue_Upd