Original sentence: " They were unable to see a "meaningful" difference between any brands of oil which carried the API starburst symbol, but suggested that synthetic oil is "worth considering for extreme driving conditions high ambient temperatures and high engine load or very cold temperatures.But our test results relate to the most common type of severe service - stop-and-go city driving.In July 1996, Consumer Reports tested motor oils in a fleet of taxi cabs.In their article, they noted that "Big-city cabs don't see many cold start-ups or long periods of high speed driving in extreme heat