0w20 different flow rates?

[spice]

Hello

Im going to use a 0w20, ive picked 2 oils of 0w20 but with different 40deg/100deg viscositys

Ive done a basic flow tests, but the oil with the oil with the higher viscosity readings actually flows alot faster??

Im confused, I thought the lower viscositys figures would see fsster flow??

Also is a higher vi reading always better for performance?

Thanks lots

 

[OVERKILL]

VI is reflective of the oil's resistance to thickening above 0C. An oil with a higher VI will thicken less from operating temperature down to somewhere below the 0C mark than an oil with a lower VI. This is desirable for fuel economy and if you short trip a vehicle, the lubricant will be marginally closer to "optimal" than an oil with a lower VI.

This won't however have any real impact on wear or flow. Any approved lubricant of the same viscosity used within its intended temperature range will provide comparable results to another.

That said, if you were to encounter extreme cold, looking at the cold performance specs of the product (reflected in CCS and MRV) will allow you to determine which oil thickens the least at temperatures well below OC (independent of VI). The lower the CCS/MRV values, the "better" here.

 

[CT8]

A higher VI on a finished product generally means more viscosity improvers.

 

[LotI]

Originally Posted By: CT8
A higher VI on a finished product generally means more viscosity improvers.
You mean viscosity index improvers?

 

[geeman789]

0w20s all flow good... you are splitting hairs if you are "worried..." about flow... seriously.

And some here worship high VI numbers ... but in real life, I'm not sure it really matters.

Buy a brand name 0w20, and stop worrying ... !

 

[zray]

My
Originally Posted By: spice
Hello

Im going to use a 0w20, ive picked 2 oils of 0w20 but with different 40deg/100deg viscositys

Ive done a basic flow tests, but the oil with the oil with the higher viscosity readings actually flows alot faster??

Im confused, I thought the lower viscositys figures would see fsster flow??

Also is a higher vi reading always better for performance?

Thanks lots


I really don't understand any time going spent on flow rates ? What your oil pump does is not like poring oil out of a bottle. For every turn of the oil pump it will pump the same quanity of oil whether it is 0w-20 or 15w-50. The oil will get to the bearings just as fast if it is thin or if it is thick. It's a positive displacement pump, every revolution will pump the same amount. The flow rate has nothing to do with anything going on inside the engine.

Z