We've had two rounds of the championship already, with teams sticking to their decision to run KERS (or not) during both races. Now, though, BMW and Ferrari have changed their minds and heading into the Chinese Grand Prix, we're looking at a different KERS lineup on the grid.

BMW
BMW have struggled to encorporate KERS into both their cars, due to the differences between their drivers. Heidfeld has been running the device since the start of the season, with varying degrees of luck. Kubica, though, is much taller, and therefore heavier - despite going on a crash diet over the winter. He couldn't run it, but BMW have worked hard on making a lighter car, and therefore allowing the Pole to fit the device. He will be able to run it on Friday to test out whether it works or not. Presumably the weight difference will affect the handling of the car, so it may be that Kubica decides not to run with it until they can sort that problem out.

Ferrari
Ferrari were a surprise KERS entrant at the start of the season, as they'd suggested development wasn't going well. However, recently, Massa suggested that without their KERS device, there really wouldn't be anything that worked on the car. I can't quite figure out why, then, given the disasters the team have already experienced, they are taking off the one thing that has made them even slightly competitive. Neither Ferrari car will run the KERS device in China, and the reason they give is safety. I do understand that it is better to be safe than sorry, especially when we're talking about stored electricity. Raikkonen suffered a face full of acrid smoke at the last race, and it's understandable that precautions need to be taken. However, they really need the device to get any kind of results, and I worry that this will be another decision that doesn't work in the team's favour.

We'll be keeping a close eye on what other decisions are made during the Grand Prix weekend, because I have a feeling these won't be the only ones.