[Steiglitz]

LifeTech, I was wondering what you base your opinion on, in regard to not using synthetic before the first 5,000 miles. Many cars come from the factory with synthetic oil. In my 2007 Yaris HB, I dumped the factory fill at around 1,500 miles, then poured in Mobil1 0W-20.

As to MPG, if you take the best oil and the worst oil and run them in a car, there will be little or no difference in MPG, and perhaps 1% or less. This issue has been debated countless times on countless forums and nobody has shown a noticably increase in MPG between dino and the best synthetics, when using hightly controlled scientific testing.

I run synthetic oil in my Yaris, but not necessarily for better MPG....I want engine longevity, smoother running engine, that sort of thing.