Mobil1 Synthetic vs Mystik JT8 Semi Synthetic, run cooler? My test r

[alarmguy]

Its well known in here that I stick as close as I can to use the recommended oil in my 2014 Road King as required by Harley Davidson.
The thinking is, simply, no different then any other car, truck, boat or piston aircraft. I use the recommended fluids, but for some reason, its the Wild West with motorcycles and I suspect the reason is, that they are more of a toy for some people, then a serious piece of machinery.

Anyway, its known in here that I use an HDEO in my 14 Road King, Mystik JT8 semi-syn 15/50 has performed perfectly for over 20,000 miles now with multiple terrific UOAs posted in here. Harley only recommends their own oil, yet as an emergency if not available an HDEO of CH4+ or higher is acceptable, even though it says change back to HD oil, I simply use an HDEO full time.

I had an 8 gallon supply of JT8 and I also use it in my boat, the supply was getting low this spring and I saved what I had so I would know I had enough for the boat oil change as it is a mail order item. I also thought this was the ideal time to test out a theory as I have seen people swear up and down in some motorcycle forums that engine oil will run cooler if it is a full synthetic. I can even say that I myself could see some reasoning in that, at the same time, I was not looking to change oils but just a fun test.

So for the heck of it I purchased a 5 quart container of Mobil 1 15w50 full synthetic that only claims an outdated HDEO rating of CF on its website, its not even on the container anymore. But at least, in my mind, it was something better then maybe running a gasoline only "S" rated motor oil.

I know the oil temperature that my Road King runs at like the back of my hand, temperature is indicated by a Harley Davidson Oil Temperature Digital Dipstick, the sensor is always submerged in the oil pan.
Harley lists normal oil temperature of 230 degrees in the shop manual for the 2014 touring bikes.

Mystik JT8 15w50 -
Typical summer time temperatures of 87 to 100 degrees, 2 up, 80 MPH interstate for approx 100 miles will always produce the highest oils temperatures, even though at these speeds the highest amount of air is being rammed through the oil cooler, the typical oil temperature will run 249 to 257 degrees.
Stuck in beach traffic about 2 miles right before the beach produced the highest temperatures I ever saw on the bike one summer of 267 degrees. I since installed a Lenale engine fan for those VERY rare times I am in beach traffic. The fan does stabilize and reduce indirectly through engine cooling the oil temperature by a few degrees when turned on.

Ok, so my test of the oil below on 6/27/20, same run to the beach, temps could have been a bit warmer in the morning but overall pretty much the same conditions experienced over the last 5 YEARS with the Mystik JT8 on this run.

Mobil 1 15w50
There maybe something to what others have posted on full synthetic runs cooler or maybe not, there is a difference, however slight, I am not so sure it is in a margin of error but I have done this run so many times with the JT8, at the same time this is the only time with the Mobil 1 but I feel confident to say the oil will run, however insignificant slightly cooler with the Mobile 1 over the Semi Syn JT8 by about 1 to 2% and why I say insignificant, maybe that difference would be greater if JT8 was a full conventional.

Results with the Mobile 1 15w50
Same conditions, 2 up, 80 MPH, interstate for approx 100 miles morning temps 85 or so degrees warmer by the time we got there.
Oil temperature to the beach ran 247 degrees.
Oil temperature on the return trip 251 degrees. (oil temp on the return trip is always hotter due to it being the hottest part of the day 90+ degrees)

It is premature to say this, but I feel comfortable to say, oil temperatures with the Mobil 1 15w50 will most likely result in a 1 to 2% reduction in oil temperature. Not significant by any means, but I think safe to say it was measurable.

Ok so this was only 1 run with the Mobil against countless runs with the Mystik over the years, so at this point, based on the behavior of the oil temperature during a two hour (each way) run I have a feeling this will hold true. Time will tell, I am considering keeping the Mobil 1 in for now and further test it, who knows, MAYBE I will even run a UOA (for fun) or maybe do a second OC with it and run it the full summer.

(Ok, so here is an interesting story, I also measured the highest oil temperatures EVER, using the Mobil 1. Stuck in brutal beach traffic 3 miles before the beach, worst ever in close to ten years. Took over 35 min I think to go 1.5 miles, oil temperature even after turning on my Lenale engine fan, climbed to the low 270s. 271 for sure, possibly 274.
I was shocked the temp kept going up with the fan on, slowly, I think it was stabilizing in the low 270s, then, the engine started to stumble, stalled and restarted right away, it was at that point I said the heck with it and rode the bicycle lane into town and to the beach.
(the police officer who pulled me over when someone called them on me for riding in the bike lane was very nice, I respect police officers and treat them with respect, they have a job to do and many times a rough one at that, he ran my license and let me off with a warning after listening to my story because it was true, I thought I was breaking down)

 

[alarmguy]

BTW - I noticed no ill effects of running the Mobil 1 15/50 over the Mystik JT8 15/50.
In fact, I would have never been able to tell one from the other as far as noise, chatter or clatter during this trip.
Im seriously thinking of running a UOA after a couple thousand miles, curious to compare it to the JT8 now that the Mobil 1 also got killed with 270 degree heat.

 

[BigCahuna]

Is there a way you can to test your dipstick thermometer, to see how accurate it really is?. 270 doesn't sound like a super high temp for oil in a Harley. And does you bike have that system that shuts down the rear cylinder if it gets too hot?. I would bet your bike would be like sitting in a campfire when your not moving. That's another reason guys either change out the exhaust system, or at least gut the cat in the pipe.,,

 

[Bonz]

Thanks for the report and detailed account of the results thus far. I like your thinking, leave it in there for an oci and see what you get.

I wouldn't be concerned about the exact accuracy of the dipstick thermometer. Like dyno runs when comparing tuning changes on a bike, use it as a relative indicator because it is what it is no matter what the number reads.

 

[DB_Cooper]

Interesting experiment. Old school oil temps tell me 260*F is very-very HOT. When I worked with Porsche 250*F was an absolute upper limit for oil temps on the air cooled engines. Have things changed?

 

[BusyLittleShop]

If you want to see a measurable drop in temp try running a 30 grade...

Quote DrDave
My old Harley really liked 10w-30 Amsoil. These was a significant
reduction in wear metals going from 15-40 to 10-30. There were no
consumption issues. It certainly started easier. By easier I mean it
spun over much faster. The motor seemed quieter, and Harley's need all
the help they can get in that department.

 

[Bonz]

BLS, can you offer anything other than cut and paste from someone else's post or the predictable 30 weight B(L)S?

Harley-Davidson doesn't recommend any 30 weight in any riding condition.

Read the room, do you really believe this info has any play in this thread whatsoever talking about a Harley Davidson and the desires of the OP for the oil he runs?

 

[Jimiii]

Alarmguy, just a few thoughts on this multi post ongoing saga. Although H.D. Does only recommend diesel oil in an emergency as a suitable substitute for "genuine HD oil, Harley oil doesn't claim to meet any specifications per their bottle. Just that it's the correct oil for a Harley. I don't know what ( if any ), diesel rating Mobil 1 15W50 would qualify for, however, when Mobil stopped marketing 15-50 as a diesel oil, they they also stopped listing the certification. It "MAY" still qualify as a higher C rating. An example of this is many, if not all 15-40 oils will pass the Jaso cert, but manufacturers don't wish to pay for that cert, as they don't market the oil for use in wet clutches. I believe rotella no longer lists Jaso cert but that doesn't mean it no longer will pass.
As I said previously I have used Mobil 1 15-50 in my Limited (2014), since I bought it August, 2017 with 5,000 miles on it. It is now pushing 40,000 miles. I haven't done an analysis on the Limited, 15-50, as I have lost my connection that did my analysis when I had the Goldwing. But with my 4,000 mile oci's I am confident it's holding up ok. My oil pressure remains consistent from fresh to drain. If you do send in a sample, Mobil lists the viscosity of the 15-50 as 18cst @100 C.
I have enjoyed your posts. Thanks.
One last note, my personal opinion is that Hiflo filters are of poor quality. I use Wix 57148. They aren't listed as an EP, but are constructed the same. The synthetic media is attached to a wire backing, and are reverse engineered to the exact specs of the HD product. Not just a filter that will fit, like most other aftermarket products.

 

[BusyLittleShop]

Originally Posted by Bonz


Harley-Davidson doesn't recommend any 30 weight in any riding condition.


You're right... I was thinking they did... he still has the option of running a 40 grade to lower temps...

 

[alarmguy]

Jimlli,

Thanks for your post, feedback and WIX number. Yeah, the HiFlo seems on the surface rock solid, heavy, well made ... but chances are Ill simply be back to the HD filter, I do see the WIX also claims down to 5 microns so good to know and who knows, it will be a thought in the future and I actually noted the number..

I guess it must be the way some read my words, or maybe its the way I write but it seems to ruffles the feathers of some people. )
I simply state my reasons for choosing a product and some just dont seem to be able to live with that. You will rarely ever see me discount others reasons unless its asked to being discussed. I suspect for a select few, very few in here, they get crazy that I choose an oil for my bike on the theory that I do, I dont know why but ... whatever

Which brings me to this -
There is no doubt in my mind that any of these oils are ok in a bike, assuming its the 50 weight, ironically what is called for by Harley )
Doesnt matter if its a Conventional or Synthetic from Mobil, Valvoline, Super Tech, Castrol or Mystik it drives some crazy why I choose Mystik.

Do I believe one oil is better then the others? Yes, does it matter much? no
But here is the million dollar question, how does one know which is better?
As far as I am concerned its impossible to know. We never know the actual wear tests, nor actual tear down tests ect. Its why I give engine manufacturers the benefit of the doubt, that they know what is best. So I go, as best I can with what they say, does that mean its the best? No

Anyway, thanks for your well said post, as you noticed my desire to stay within the HDEO rating I justified it a little with Mobil CF.
Do I think its better for my engine, using a full syn like Mobil 1? No, maybe or yes, only because I have no proof and I do change often. At the same time its easy to buy in my area and recently the price reduction to $22 makes it a value to me. At the same time if it goes back to the $27 range, then I wont look at it the same.
I do agree with your theory that it is possible they no longer bother with the C rating, but again, I dont know and it doesnt bother me much at all. Its a very good point that you made.

Chances are I am going to run it again, curious about it, curious enough to do a UOA on it as well. Lets say it comes up better then my very good UOAs on the Mystik, I might even switch, who knows. I dont think UOAs are the end all of everything, its more of a fun thing for me.
There is an oil out there that meets HD specs perfectly and that is 15w50 Amsoil diesel oil, but the cost isnt worth it to me at my change intervals but would be a fun project I guess for someone who uses HD oil at the same price point and wants to try something different. Then again so does the Mystik.

I appreciate your thoughts on this.

 

[alarmguy]

Originally Posted by BigCahuna
Is there a way you can to test your dipstick thermometer, to see how accurate it really is?. 270 doesn't sound like a super high temp for oil in a Harley. And does you bike have that system that shuts down the rear cylinder if it gets too hot?. I would bet your bike would be like sitting in a campfire when your not moving. That's another reason guys either change out the exhaust system, or at least gut the cat in the pipe.,,


Good questions,

- Keep in mind all non water cooled Rushmore bikes have a oil cooler, it is for the purpose of keeping the oil cool at highway speeds. Which was something I did not know many years ago until someone explained to me the pistons are sprayed with oil to cool them, this happens at higher oil pressures which of course happens at higher speeds.
I did, many years ago swap out the 8 row stock cooler with a Jagg 10 row, I figured the extra 2 rows of cooling could not hurt in the blazing heat of SC sping/summers.
Actual measurements though, didnt make too much of a difference, I like to believe maybe 5 degrees but not even sure of that. Jagg does state if you swap out the cooler you should also replace the OEM HD oil filter adapter with the Jagg adapter because the HD one will still not divert as much oil to the cooler as theirs will but I didnt want to mess with that, I was simply looking for a little extra something taking into account my hotter then most climates. Maybe do not know the midlands of SC average daily high is hotter then Florida in the summer but not as hot as AZ *L*
Anyway, swapping out the cooler was a fun for me project but most likely not worth it unless maybe I change out the adapter.

The HD digital dipstick oil temperature gauge has impressed me, from what I understood the early versions were trouble prone to some (in the forums anyway)
For me its been rock solid, love it, simply because I like instrumentation and how things work. I TRULY am amazed it still works, good god the heat that it endures, I never even replaced the battery in it. though I think I will because darn it, it gets used a lot and most likely should be replaced.

With that said, to answer your question, you know, I think many years ago, someplace in my garage I have a Digital (or analog) candy thermometer that I bought before my wife got me the HD one for a present. A candy thermometer is used to melt candy or something and goes up to 300 degrees/something like that.
I do think I compared the temperatures at the time. Anyway, you peeked my curiosity enough that I will check those temps again and compare. I have no idea if Ill find the one I bought in my messy garage but there are other ways. I could simply use a digital meat thermometer and check the temp up to around 200.
Anyway, this is why I am sure it is accurate. I believe the thermostat on the OEM HD oil Filter adapter opens up and starts letting oil flow to the oil cooler at around 190/200 degrees (its been a while so dont hold me to the exact numbers) I actually know when it opens and starts letting oil flow, simply by touching the inlet pipe on the oil cooler and feeling it get hot, that approx temperature also shows up on the Digital Oil Temperature gauge which confirms its working. ( I used to check it)

Also as I started posting in here this morning, I put a simple house hold digital gauge on top of the Harley oil gauge sitting in my garage, bike is dead cold and both gauges read within 1 degree of each other at 81 degrees so we know we are starting off at the right temp and things not totally out of whack.

-Also keep in mind I have the Lenale engine fan, I use it maybe 3,4 times a year, if that, only when in heavy traffic, when you turn it on, it cooks your leg but stabilizes oil temp and it looks much better then the OEM horn but I think if someone asked I would recommend the Mighty Mites for heavy duty cooling, then again, I dont own them or know anyone who does or how good they are.

- ETMS, yes, designed into the Rushmore bikes for rider comfort according to HD. Its turns off the fuel injector on the rear cylinder, effectively shutting down the cylinder when at dead idle, I keep it turned off all the time and only time I turn it on, is when I turn on the fan and get a bit more desperate after the fan, which means stuck in traffic and want to keep things as cool as possible.
To turn it on and off at will, you simply move the throttle forward and hold it for a few seconds, an indicator near the speedometer indicates off and on.


- Ahh, the CAT !
The CAT was gone the first year or so that I owned the bike. Did it make a difference? I would like to believe so, I know some people rave about the difference, I cant really say that but for me the best part was the slightly, deeper throaty sound AND according to Fuel Moto it allows some oxygen to mix in with the air, as well as a little crosstalk between o2 sensors which might increase the AFR a little bit. I was thrilled when I read that! *L* Though Fuel Moto says its a reason to switch to their headers, for me, I just wanted a chance of a little extra fuel, I guess if I had a processor maybe a reason to switch.

Best part was the sound for me, followed by the POSSIBILITY of a little extra fuel, followed by getting rid of that furnace under our feet.

 

[alarmguy]

Originally Posted by Bonz
Thanks for the report and detailed account of the results thus far. I like your thinking, leave it in there for an oci and see what you get.

I wouldn't be concerned about the exact accuracy of the dipstick thermometer. Like dyno runs when comparing tuning changes on a bike, use it as a relative indicator because it is what it is no matter what the number reads.





Sure thing Bonz,
As you can see to my other reply, Im confident in the accuracy of the HD digital dipstick and think, years ago I checked it and as you see the other way was also simply feeling when the oil cooler thermostat opens to let hot oil flow to the cooler matches up with the temp gauge but its easy to check and think for the fun it I will.
_________

DB_Cooper -
Well, we dont want the temps too much higher or the oil will start to smoke but HD engines take this into account, 100s of thousands of bikes on the road and most pay not attention to the oil temperature and rightfully so, its designed this way.

 

[BigCahuna]

Well that answered the question I was going to ask. I have a whole exhaust system for a '12 Ultra a friend gave me. I was going to ask if you wanted it to test how different it would run with out the cats in it. I took the mufflers, and put them on my '05 Road King because the SE mufflers were rotting out. You would have had to drill the cat stuff out, and if you didn't like it, you could put your stock system back on. But it looks like that ship has sailed.,,,

 

[alarmguy]

Yeah thanks for the thought ^^
It was worth it to me, cost was less than $30 for the drill bits and extension. It was a gratifying MOD if anything for the slightly deeper rumble. I had loud pipes on other non Harleys and I didn't want to go back to that as it starts to take a toll on you for long trips.
Plus I have enough ringing in my ears as it is!

Ps. There are some that says it's impossible to get everything out with the drill. That is untrue and I confirmed it with the angled piece of metal tent stake. When I was done I ran it up and down the inside of the pipe and it was buttery smooth. I think the mistake many people make is they only buy a 1 inch drill bit.

I started with a 1 inch and then finished it up with a 1 1/2 inch which just fits in the pipe perfectly.

 

[Merek]

Rotella now has the T6 available in 15w40 which is worth a shot since you like running HDEO's. Mobil 1 has their V-Twin oil in 20w50 and also Castrol has the Power 1 V-Twin 20w50 that they recommend for Harley's. That's awesome you can check the temps with ease as you can try out the different oil's to see if one runs cooler than another.

 

[Bonz]

From previous posts and interactions, not that you may have seen them all, Xw40 weight is recommended for colder climates per Harley and the riding he does pretty much dictates an Xw50 weight based on ambient temps and what he has shared.

With that said, I agree the T6 15w40 has some play in other applications for motorcycles.

 

[alarmguy]

Originally Posted by Merek
Rotella now has the....That's awesome you can check the temps with ease as you can try out the different oil's to see if one runs cooler than another.


Yes, its been a great device for people who are into this stuff. I forgot to mention one other cool thing about it is not only the temperature but it also tells you the oil level on its LCD screen.
After your post, it occurred to me, here we are years later. I could have simply been taking photos of the oil temperatures all this time and had them saved by time, date and conditions.
Oh well, like I said, Im into this stuff but not possessed ...

I took 3 quick photos, kind of rushing, leaving for work soon and a bit tricky in the dark garage as well as trying to take a clear photo of a moving LCD screen.
But this gives you an idea, oil level are the "bars" on the left, temperature is where you see COL which is a scrolling word that says COLD OIL and then after that it will say the temperature. It also lets you know besides the bar graft of the oil level but will flash "high oil" or "low oil" as well, since both extremes are bad.
This device replaces the standard OEM oil dipstick.

 

[krismoriah72]

Originally Posted by Bonz
From previous posts and interactions, not that you may have seen them all, Xw40 weight is recommended for colder climates per Harley and the riding he does pretty much dictates an Xw50 weight based on ambient temps and what he has shared.

With that said, I agree the T6 15w40 has some play in other applications for motorcycles.



Also Delvac Extreme 15w40 (rated SM) etc

https://www.bobistheoilguy.com/foru...vac-extreme-synthetic-15w-40#Post5458709

 

[troop]

Maybe give Redline 20w60 a run ..
https://www.redlineoil.com/20w60-motorcycle-oil

 

[alarmguy]

Im not looking for a new oil, so 15/40 or 20/60 not for me, just reporting a comparison between a 15/50 full syn and semi syn as far as operating temperatures.

I dont use or believe in boutique oils who stamp "motor cycle oil" on them. I prefer the standards as dictated by the engine maker and in my case it is not motorcycle oil.
The oil Mystik JT8 I use cost $3 a quart and the Mobil 1 syn that I am experimenting with cost $4.50 a quart.

Also if your one to believe UOAs I posted at least 3 or 4 stellar UOAs using oil that cost $3 a quart and within Harley HDEO temp use requirement.

No big deal, just testing oil temperatures though, between the two oils in more severe conditions.