Mercedes technical director James Allison estimates the sidepod changes between Mercedes’ 2017 and 2018 cars is worth around a quarter of a second.
The W09 – the first car Allison has been heavily involved in after joining Mercedes earlier last year – features tighter aerodynamic packaging around the sidepod to the rear of the engine cover compared to its predecessor. In a video released by the team explaining the differences between this year’s design and last year’s championship winner, Allison says the sidepods were a major area of focus over the winter.
“The biggest one of those [changes] is down here in the sidepod,” Allison said. “We’ve done an awful lot of work down there to try and make that car really, really slender. If you compared it to [the W08] you can just see the difference. You can see that the bodywork bulges out around about where the engine and exhaust pack is.
“On the new car this is a much, much more slender thing. It doesn’t look like much of a difference, but actually when you add it all up that is something like a quarter of a second just there.
“It doesn’t look like much of a difference but it was actually a huge amount of work – a lot of hair got lost in that project – but the end result is something which is pretty to look at, but much, much more importantly is an awful lot quicker.”
And Allison also highlights the front suspension arrangement as another significant change on the new car.
“After that you start to get into things that are much more subtle, and you need to be something of a petrolhead or an anorak to really notice. But the sharp-eyed ones among you have probably noticed the front suspension looks quite a lot different to last year’s. The wishbones have been raised, that’s something that has been a trend on Formula 1 cars in the last few years.
“Raising those front wishbones brings better aerodynamic performance. It’s a big structural challenge but it’s definitely something that brings you more downforce and a quicker car.”
The W09 was second fastest on the opening day of the second pre-season test in Barcelona, with Valtteri Bottas exactly 0.2s slower than Sebastian Vettel’s Ferrari.