Not on my car, the manual says the opposite, get into a high gear as soon as possible, skipping gear changes if possible. The dash board recommends gear changes, much sooner than anticipated and even leaves the engine sounding like its laboring, all with the goal for better MPG.
The issue is the faster the engine is spinning the worse the frictional losses are.
My gear change often says change up but if I do the MPG goes down.
I need to hold off slightly before it actually makes it better.




400m and a tank a week, yep it's costly, but meh...
As far as I can tell the prices for rail fares in that article are not adjusted for inflation and the fuel prices are defiantly not adjusted for inflation so surely I'm comparing like with like.