An interesting read, oils aint oils, or are they?

[B6mick]

http://www.xs11.com/stories/mcnoil94.htm

[aussiebandit]

Your right, that was interesting.  

I've offen wondered about whether I was right in using Castrol GTX in my previous bikes.   It never seemed to make much difference, they all still changed gear, didn't appear to get overly hot and ran well, considering their age.

In the B12, I run whatever the shop puts in at the time of service.  This is mainly because in the 4 years I've had the B12 I've never had to top the oil up between servicing.

[ray nielsen]

I've been having my used oil tested by Blackstone Laboratories in Fort Wayne, IN for a couple of years now.

I use Mobil 1 15W-50 automotive oil in my bikes, a Kawasaki W650 and a Suzuki Bandit 1200.  In the cars I use Mobil 1 5W-30 until recently until I went to Mobil 1 Truck & SUV 5W-40.

I run extended mileage between changes, 6-9K on the bikes and 8-10K on the cars.

In every case of analysis the viscosity at 100 degrees C has been within normal ranges, even at those mileages.  Of equal importance, in my mind, is the Total Base Number (TBN) an indicator of the oil's resistance to acid formation.  Using a TBN minimum of 1 for a minimum, the high mileage samples have indicated lots of antacid protection left.

Mobil 1 15W-50 begins life at a TBN of 12, the 5W-30 at about 9.  Even after extended mileage the minimum in my bikes I've seen is 5.2 and 3.8 in the cars.  This would indicate I'm changing with "room" to spare in both cases.  

While Mobil 1 15W-50 does contain about 50-60 Parts per Million (PPM) of molybdenum disulphide it has caused NO problems with clutch slippage -- it seems to improve shifting a bit too, at least compared to regular, mneral based oils like Suzuki's 10W-40 and Castrol GTX.  

I believe the synthetics ALL provide better low temperature lubrication and have more reserve film strength at high temperature compared to regular motor oils.  That and the extended mileage between changes seems to make the cost of operation about the same in my mind.  

I pay $5.69/qt. for Mobil 1 vs. $2.49/qt. for Castrol GTX as a reference.  That makes 6K per change with the synthetics only marginally more expensive than 3K per change with regular oils.  Using a new filter at each change actually makes the synthetics cheaper overall.

My two bits worth on the subject.

[pmackie]

This subject sure gets covered a lot...

Ray, unless I'm really out of the loop, the Mobil 1 15W50 does NOT use Moly Disulphide, but is likely using a moly as part of its antioxident adpack. This is quite common in Diesel Engine oils. Moly antioxidents should not cause any problems with the wet clutch. Moly Disulphide on the other hand is a solid lubricant (similar to graphite in properties). I would avoid these solids (including PFTE, or Teflon) as they tend to cause more ring groove fill in, among other things.

True synthetic oils should require less VII (viscosity index improvers) than conventional oils and therefore should retain more viscosity over time. Diesel Engine oils generally have more shear stable VII's as diesel engines are harder on VII than gasoline engine oils.

So...optimal viscosity retention should be found with synthetic diesel engine oils.

Remember though, that higher viscosity is not always the goal. Higher speeds and lighter loads need lower viscosity. IE: generally motorcycle engines need lower viscosity than auto engines, but transmissions and gears need higher viscoisities, so lubricating M/C engines is a bit of a comprimise (especially high reving, 4 cylinder engines).

I use a full synthetic 0W40 diesel oil, Canadian spec XD-3 Extra 0W40. Another good option is Mobil Delvac 1 (5W40) or Shell Rotella T synthetic. I feel that SAE 50 (15W50 & 20W50 or even 5W50) oils a overkill for 4 cyl engines. Likely big air cooled V-Twin's can make a case for SAE 50's.

[B6mick]

I have always, thought that oil companies, should climb back up their own bumbs with some of the BS they come up with.
I use a oil that I am happy with its price, and have been impressed, by its sucess in racing etc. But I do admitt, when times where tough, to using, nothing but safeway no name, no brand oil with change out of $6 for 4 litres. Its spec's excceded all spec's required to run my old and trusty FJ1200. I was couriering everyday on the FJ, so new oil was better than the old and I personally did the last 100 thousand miles on that motor with that shitty no name no brand safeway oil. BTW the FJ had 240 thousand + k's on it when I sold it and it was still going strong. (Thats 140 thousand miles) and the only internals replaced was the clutch plates.

When I first got my FXWG hardly dangerous back in the 80's, the oil of choise, from the shops was castrol CRB50 at just under $20 for 4 litres, I used to use Rimula X 50W, truck and tractor, at $32 for 20 litres.
After a very long haul we tore the engine down and the bike shop boys couldn't beleive how clean the engine was. BTW the only reason I pulled it apart was I started loosing oil presure, top end was fine, a worn crank pin, was the whole and only problem, just a pity it meant a full engine rebuild. But it proved to me and a few of my mates that shells Rimula X was not a bad choise.

[aussiebandit]

...........When I first got my FXWG hardly dangerous back in the 80's, the oil of choise, from the shops was castrol CRB50 at just under $20 for 4 litres, I used to use Rimula X 50W, truck and tractor, at $32 for 20 litres........But it proved to me and a few of my mates that shells Rimula X was not a bad choise.

Why does it not surprise me the Rimula X Truck and Tractor worked well in a Harley Fergusson.....  

[Bazza]

I swore I would never visit another oil thread!

My good friend who is a member of the Petroleum Engineer's club puts it very simple.

Synthetics - Are much more resistant to shearing of the polymeres which occurs a good deal in motorcycles by the grinding action of the transmission gears. Synthetic oil's polymers are more consistant than dyno oil because they are enginered to be. In layman's terms, Synthetic oil takes the properties of Dyno oil and just makes the good parts more consistant.

Viscosity- Low rpm V-twins need high viscosity oil. Oil passagways are much larger in V-twins vs higher reving inline 4's. which require higher volumes of oil to flow through the engine - thus thinner oil is better as it's easier to move. Also bearing tolerances are tighter in inline 4's versus V twins, so thicker oil is better here. In otherwords. High RPM needs high flow, low RPM needs visocosity.

Car oil vs Motorcycle specific oil?

The difference is what they use for friction modifiers. He tells me the best friction modifier for a bike is zinc (it does not affect wet clutch's) But Zinc kills catalytic coverters so it can't be used in cars anymore. There are several different synthetic friction modifiers now that adress these issues.

But he admits, that one can make an engine last just as long with dyno oil versus synthetic, but change frequency would have to be increased with Dyno oil. We all have heard about grampa's chevy running a million miles. It was because he changed oil!

A word of caution he says, over extending the change frequency of synthetic oil (running it too long) can damage an engine badly also, if sludge begins to form. He is seeing this occur often.

[mike]

Here we go again !    
 

[Bazza]

But to add to the article, the higher priced motorcycle specific oils are usually due to the age old habit of motorcycle dealers taking advantage of us.

[RowdyRed94]

The article is 12 years old. I'm not sure how much is relevant any more, considering the dramatic changes in synth lately.