Trying to pick a fleet oil for my 3 car fleet

[CATERHAM]

Right, and even then we're talking maybe a 1% difference in fuel economy that's attributable to the oil alone based on typical OTC oils.
Can you accurately measure a 1% or even 2% difference in fuel consumption? I know I can't.

If you want to maximize the oil's affect on fuel economy, select an oil with the highest viscosity index (VI) and the lowest HTHSV. In a 20wt oil that's the Toyota 0W-20 I mentioned previously and in a 30wt oil it's PP 5w30 (VI 177, HTHSV 3.0cP).

 

[Cooker]

I certainly cannot measure a 1%-2% difference

Well after all the discussion I think I am going to be down to 2 oils on the shelves in the garage. I am going to run PP 5w30 in the Prius and the Journey for a while since I just picked up a few 5 quart jugs of that on sale.

The Van will just be the odd one out. And currently will be on a diet of NextGen Maxlife for a little while since I got a great deal on that after rebate.

Thank again to everyone for the discussion