Good catch, I missed it like most it seems.
"I guess that will be where we will look at that. It's added some weight, so it's a few kilograms on top of what we thought we would be running."
That means the Renault teams will likely have to persevere with the old MGU-K, understood to be around 5kg heavier and less powerful than the new unit, until at least May's Spanish GP at Barcelona.
A few kg, maybe 5*, more and "less powerful" then the new MGU-K for five races and hardly any headline about it? After the last long three years full of talk about the importance of power pack integration and the interdependence with ERS?
To be frank I expected much more noise about this. In any case this is highly interesting. First a few kg less for the MGU-K is impressive, even if it is less then five. More powerful has to be understood in the context of that article written in mid 2016:
Taffin admits that power delivery has greatly progressed since the early days of the Power Unit back in 2014.
“Power delivery of the stored energy is now performed around almost the entire lap,” Taffin confessed. “We have reached outstanding levels of overall efficiency. Today, the MGU-K is capable of producing 120kW, which is the equivalent of 160bhp, around almost the entire lap. The moment the driver steps on the gas pedal and we are no longer grip limited, it applies full power. It’s no longer if the driver wants to use it or not. The power is available. It’s all controlled automatically.
For 2017 the energy efficiency of the patrol engine has been increased and 5kg more fuel has been added. This means more electric energy to be harvested by the MGU-H and it's increasingly likely that only the FIA rules are restricting MGU-K output and no longer the available electric energy as has been the case in the earlier days of this engine formula.
Electric motorgenerators are very efficient indeed but operating close to the max MJ output and harvesting allowed or on it will mean more heat output which in turn forces better insulation and cooling. A considerably reduced MGU-K mass should result additionally in higher heat peaks as there is less material to sink the heat in which compounds the insulation problem.
In short they might have been too aggressive with their 2017 MGU-K unit.
H2H
*Remember all the talk about the Force India drivers having to drop 2kg.