Originally Posted By: 06VtecV6
Guys, I wouldn't have believed it unless I just saw it unfold and and bloom this past few weeks. I'm on (and been using 5w weight to the exclusion of 10w FOREVER) a 5w-30 fill and getting no better then about 17.xx mpg. Ever since I topped off with 10-30 PYB, that mileage has creeped up to about 19.1 mpg!
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-advanced-fuel-economy
Originally Posted By: Mobil
Low viscosity, advanced full synthetic formula
Helps increase engine efficiency and improve fuel economy, based on
0.2-2.3 percent potential fuel economy improvement obtained by switching from higher viscosity oils to a 0W-20 or 0W-30 grade. Actual savings are dependent upon vehicle/engine type, outside temperature, driving conditions and your current motor oil viscosity.
17Mpg 0.2-2.3% improvement = 17.034-17.39Mpg and that's going to a DIFFERENT grade of oil
designed to
increase fuel economy.
You are claiming roughly a 12% fuel economy gain on the SAME grade simply by adding an oil with a slightly inferior winter rating.
This is called "junk science" and has absolutely ZERO value.