How to get 90+ Eco score consistently?

That one is usually flaky anyway. It kind of assumes that you're up to speed and slowing very gradually.

To get 90+ consistently you need a really high start score. The cruise score usually just gives 4 bars instead of 5 for most practical situations so your start score has to make up for some of it.

 

I feel the Eco score has very little to do with good fuel economy. I put no effort into getting high scores and I have averaged over 55MPG on every tank.

 

I ignored the eco score after a day or two when the novelty wore off. mpg is all that matters - eco score is just an approximate test of how much you know about how the car works.