McLaren Mp4-18 floor
On the MP4-18, the exhaust is in fact in the diffuser, this is return to the older format discarded by most during 2001-2002. Adrian Newey the McLaren designer did not drop this format until 2002 as part of the packaging for the new Mercedes engine in the MP4-17 (and subsequent MP4-17D in 2003). On McLarens previous to this Newey placed the exhausts low in the middle diffuser tunnel. When the MP4-18 first ran it was clear the exhausts returned to the diffuser but such was the secrecy around the car and the confusing outlets on the top of the sidepods, their exact location could not be confirmed.



The curved outlets on the sidepods are chimneys for the hot radiator air. They are not exhaust outlets as they might appear as they do not have heat shields. Instead the exhausts sit in the outer diffuser tunnels, they sit about half way up the surface and such is the direction of the flow through these outer channels the flow blows through the centre diffuser tunnel (yellow trails). McLaren have fitted detachable centre diffuser tunnel walls with metallic looking upper sections to withstand the heat.