Previously the peloton would dawlde along on flat starts to stages (until the TV coverage started apparently) but now it's "Lights! Camera! Action!" from km 0. Shorter stages, better nutrition, technology, altitude training, bicarb, rice and tubeless tyres means they should be going faster anyway. "Full Gas" should be the Tour's documentary's name. The Giro at least still has a bit of the old school aura around it.
Edit - I've just been perusing the Giro roadbook (online at
Giro roadbook) and according to it, Froome's 2018 return from the dead, ride to victory in 2018 is the Giro's fastest at 40.105 Km/h just beating Nibs 2016 time 40.014 - the only 2 over 40 km/h)
Edit 2 - I don't know what the Giro roadbook is up to, but the 2009 Giro results are odd. 2 extra stages and 269.5 extra km's have been added to the results I've read elsewhere. A "technical error" to mislead innocent readers of the winner beating the other 2 on the podium who were subsequently banned?
From Cycling News
https://www.cyclingnews.com/features/the-giro-ditalia-by-numbers/
“Chris Froome in 2018 and Denis Menchov in 2009 both won with an average speed of 40.16km/h. By our calculations, Froome shades it with an average of 40.1699, compared to Menchov's 40.1671”