Originally Posted By: fdcg27
You mean that a 5W-40 provides better fuel economy than a 15W-40?
Who knew?
I have no doubt that the fuel savings claimed are real, but there are a number of synthetic 5W-40s that probably would have done as well.
Bingo!
Originally Posted By: Artem
Originally Posted By: Pablo
I don't think any of the viscosities selected are outside those recommended (?)
Definitely within the recommended viscosity spec... for that specific temperature.
Like i said though, the same can be had with a Conventional oil so besides the extended drain ability of the Synthetic, (which is what they should be advertising) it's a pointless test.
Exactly! Its an adverstisement. Put a SOPUS product, or a Mobil product in the sump and expect similar results. All this was is an attempt by a marketing dept do show Amsoil gave better mpg, when in reality it was the change in viscosity that was responsible for the gains. IMO that would be the letter "D", in the word FUD. And I'll still bet they did everything they could by changing shift points etc to tweak the results a bit more. Once again JMO.
As a side note Amsoil isn't the only company that uses FUD in their advertising.