Ok, explain 0-50 Mobil One to me then.  When it's cold it flows like it isn't there and when it's hot it gets all gooey?

 

jest kiddn' -- when its cold it flows like a zero weight oil (zero on a viscosity test flow meter scale that was set up a long time ago by automotive engineers when getting a 10 wasn't very durn likely)

And the flow rate of this oil doesn't change much at all, flowing like a dino 50 weight oil does when it gets all hot and loosey goosey.

I am a fan of synthetic oil, BTW.   You have to get synthetic oils up to over 350 degrees F to even begin to hurt them.

I would think that any FULL synthetic 10w30, 10w40, 0w50, 15w50 would likely be sufficent to keep our scoots healthy winter or summer.  

Why would a FULL synthetic 10w30 work in the summer time when Suzuki doesn't recommend the 10w30 weight when temperatures get much over the 90 degree range?  

Because the rating was set for dino oils that change viscosity greatly as the temperature goes up.  And FULL synthetics don't change their viscosity very much at all in any bike temperature range.

Mobil One was developed for lubricating jet engines -- which run up in the 400 degree ranges fairly commonly.   And why do you think Mobil One is the only oil recommended for use in a turbocharger?  Because they get right warm in normal use, that's why.

I'm getting lost here.  If all this is true, then why does Mobil One 10W40 cause an oil pressure gauge to show far greater than normal pressure on engine start-up when it is 35 degrees outside, normal pressure when it is 75 degrees outside, and then show normal pressure once the engine reaches operating temperatures regardless of outside temperatures?  High oil pressure which changes to normal upon the engine reaching operating temperatures should be a function of viscosity, shouldn't it?  If so, then this oil is thicker when it is cold.

molecules move slower cold and faster hot,cold is denser(ice?)hot is less dense(steam vapor?)....cold molecules are smaller than hot..
if you took equal amounts of 10w oil and 40w oil and put them in a glass vessal you could see that they seperate...
multi vis oils are treatted so seperation is less likley, the thinnerweight heats up and FLOWS faster than the higher weight...
but to the original thread question skat's oil is just fine for where she is...as Any cool/cold engine starting longer warm up times are necessary to insure the lube(life blood of air cooled engines)is well dispersed to all friction points...

As a side note, full synthetic oil will act 1 or 2 full temp ranges higher due to the fact that it resists thermal breakdown and viscosity change so much better than dyno...

Cold pour point and pumping threshold are useful to describe how an oil acts in cold weather.  Most full synthetic 20W50 have lower pour point and pumping thresholds in cold weather than 5W30 dyno fluid.

For example the Amsoil 10W40 I use has a -51 degree F pour point, while most dyno 5W-30's have a 0 degree F pour point.  BIG DIFFERENCE!  In general, winter and summer weight ratings ONLY apply to dyno oils, not full synthetics as my example above clearly demonstrates.

Barry, the base oil isn't oil -- it is a lab created uniform polymer chain which just doesn't change viscosity very much.  

There isn't much percentage points of additives in full synthetic oil compared to old style dino oil -- they simply adjust the base polymer chains themselves to get a given viscosity.  I doubt additives get much over 2-3 percent in Mobil One and any of the similar real full synthetics.

Having been involved in gov't acqisitions for the last 10 years or so, forgive me if I respectfully disagree.  Often times, what the gov't buys is based on who needs to be propped up financially, certainly not the best product.  Lowest bidder!  Right?!?  Would you buy a car that way?

I'm not suggesting that Mobil 1 synthetic is a "bad product."  It's just simply not the best product for the money.

With regard to Amsoil marketing, their lack of multimillion dollar marketing schemes is what keeps a superior product priced below the competition.  But each person has to interpret marketing ploys in their own way...

The government does not buy from "whomever has the best product', as every manufacturer will tell you he has the 'best product' and back it up with biased reports by testing companies that are paid by the manufacturer to report on their product. (You may have seen that expose on all the oil additives that are advertised on TV). The government sets its own MilSpec standards which bidders are required to comply with, before they bid on the contract.  The lowest bidder complying with MilSpec standards gets the bid.  There are federal watchdog agencies whose job it is to make sure that the lowest bidder who complies, gets the contract.  Favoritism is illegal and if uncovered, (and it is, from time to time) is a federal crime.  So yes, I would buy a car from the lowest bidder as long as he met my specifications.  As for Amsoil being a superior product, why isn't the world using it?  If it was that superior, by now after all these many years the truth would have gotten out and it would be a major player.  I may well be wrong, but the only places I ever saw it being pushed was by home based salesmen trying to sell it out of their garages and occasionally as a side display in a small privately owned auto parts store where the owner is also distributor.  

The third reason requires a little explanation of how you get a conventional oil from  a straight weight oil (i.e. 30 weight, not 10w30) to a multi weight oil. To get a conventional oil to act as a 10 weight oil when cold and a 30 weight oil at operating temperature requires starting with a 10 weight oil. That covers the cold side of things. Then they add what is called a viscosity improver. A viscosity improver makes the oil less affected by heat. Thus when the oil is heated to operating temperature it is not as thin as the 10 weight oil that it started out as would be at operating temperature.

A synthetic oil in it's plain manufactured form (no viscosity improvers added) is already less affected by heat. It's performance already matches a conventional multi-weight oil. So a synthetic oil is going to use less viscosity improver to get to the desired multi-weight rating than it would take to get there with a conventional oil. In some cases it may already be at the performance level you want and thus would require no viscosity improvers. Why is that so good? What's wrong with using viscosity improvers?

Well a viscosity improver will break down due to heat easier than oil does. So after a couple thousand miles in an engine the heat has caused some of the viscosity improver to break down. The oil then is no longer performing up to it's multi-weight rating. It is thinner when at operating temperature than when you first put it in there. The break down of the viscosity improver is called "shearing". So a  synthetic oil "shears back" less than a conventional oil because it uses less viscosity improvers. As you can see also, an oil with a 5w30 rating starts with a thinner oil than a 10w30 and uses more viscosity improvers to get to the 30 weight rating at operating temperature. A 5w30 then has more potential to "shear back" to a thinner oil than a 10w30 if the base oil is of comparable quality.