Did a search and went through a whole bowl of Chicken and Sausage Gumbo without finding the answer.

So whats the difference between 15w50 and 20w50. Like Mobile 1 reg syn and mobil 1 V-Twin.

Thanks

 

1st off 5w when cold and the V twin oil is formulated for air cooled engines.

 

The weight of the oil when cold, one has the properties of a 15wt and the other a 20wt oil when cold, they both have the properties of a 50wt oil when hot.

A 15wt would flow quicker in cold condition, but would not protect a lower toleranced engine as well. Where as a 20wt might take a half second longer to reach some areas, it protects enginges with a looser tolerance better.

Like in a newer car, most call for a 0-5wt oil when cold, since most are buit to a pretty tight tolerance.

Not sure it answers what you are asking, but it is the answer I have.

 

The truth is that it is formulated to sell to V-Twin owners at an exorbitant price.

 

Yep, and the difference, according to Mobil, is that the 15W is for radiator cooled motors while the V-Twin offers more temperature range. But I've met a lot of guys here who successfully run 15W with no problems. And if you'll notice, 15W is way cheaper. I run the VTwin out of habit.

 

Some of us down here use gumbo in our crankcases, so let's not get flippant with our choice of lubricants, shall we? It also makes a good grease.

The biggest difference between the two is that the 15w50 is much less-expensive. There have been three (that I know of) credible oil tests by MC mags in the past decade or so that shows that the cheaper M1 is every bit as good as the VT, and it has more friction modifiers (including moly) than the VT. That's because the latter must be formulated for use in bikes that share clutch and engine oil. Some FM's, like moly, are not good for optimal clutch operation. In an engine-only application like most cars and Harleys you want the FM's in the formula.

The cheaper M1 is usually available at Wal-Mart for ~$23/5-qt. jug. It usually fits both my criteria for choosing a synthetic oil, which is accessibility and cost.

 

V twin is 2 bucks off per qt. the rest of the month at AutoZone if you care.

 

Well my suspicions would be that if Mobil 1 makes a fully synthetic oil in 20w50, it would most likely be the same as the Vtwin, only in a different package, whereas they charge an extra dollar or so to add vtwin to the front.

In my Harley, since I know some of the tolerances are loose, I would always use some type of full synthetic 20w50.

I will agree with iclick though, the friction modifiers are probably different in the two types, and this could be the major difference.

I mean why would I trust any oil company?

 

How can it offer "more temperature range" if has a narrower viscosity rating? The "20w50" means it flows like a 20-wt. when cold and protects like a 50-wt. when hot. The 15w50 obviously starts with a thinner base-stock with more VI's and a has a broader temperature range.

 

v twinn is safe for clutch(as metrics share motor oil and clutch)not so with harley. v twinn has less friction modifier not as good for motor.use regular oil in the motor and v twinn in the primary.