Let's have a better look at the car from a selection of rendered photo's made available by Lotus F1
The renders of the car from the front show how closely the E21 represents the previous carnation but what I wanted to point out here is that the team have released 2 different renders. In the top image the car has both vertical Vortex Generators above the Sidepod Inlet and Cockpit Wings stabilizing the air horizontally. In the lower image the Vortex Generators are missing. There is a small variation in the Front Wings but as we know Lotus ran many different Front Wings last season and so it's hardly surprising to see that trend continue in 2013. Lastly in the lower image we can see the team have rendered the DRD ears onto the side of the Airbox signalling that DRD will play a part in Lotus' 2013 championship assault. (James Allison, Lotus' Technical Director also stated the team would continue to develop the concept in 2013)
As a another variation in the image below the inner vertical Vortex Generator also forms the start of the horizontal wing
From the side pictures it's clear to see that the E20's sloped nose remains, I call it as such as their nose has always been a more gradual version of the rules rather than the abrupt ones seen on the likes of the F2012. James Allison was asked during the unveil about the nose and why a vanity panel hadn't been used and rightly so he commented that additional weight (of the panel) is something that the teams are always trying to shed and the team would continue to assess it's application/merits. The team also ran a 'Pelican' nose toward the middle/end of last season in order to better extract better performance from the underside of the E20's nose region which is also missing from the launch spec. Also missing from the launch teasers are any turning vanes under the nose which likely means the team have concentrated their efforts in this region and don't want to give too much away to the other teams too early.
During the 2012 season the team adopted a split in their Sidepod Airflow Conditioners which is clearly missing from the renders and indeed the physical launch car. As I mentioned in my brief look at the car from the leaked pictures yesterday the team seem to have adopted a sharp undercut in the engine cover under the Airbox. This is likely done to maximise the upswept air from the sloped nose and re-purpose the airflow down to the rear of the car.
We can see once more that the team are edging their bets in the render department showing two variants of the exhaust solution. The physical launch car featured a Red Bull esque Downwash Ramp with Exhaust trough and cross-under tunnel but in the lower rendering we can see a more simple ramp configuration also ran by Red Bull throughout 2012 but can be traced back to Sauber early on in the season (Larger image below)
One thing I'd like to re-iterate is that although it appears Lotus may be following Red Bull's lead somewhat it seems they are yet to follow one of Adrian Newey's biggest differentiators: the halfshaft shroud. The halfshaft shroud used in different forms on the family of cars since the RB5 helps to isolate the airflow over the rear of the car as normally the halfshaft rotates the airflow creating downforce of it's own (Magnus Effect) the trouble is when you introduce another airflow regime especially one as unpredictable as the exhaust plume this effect becomes a little more erratic. I wait to see how many teams following the Red Bull exhaust styles will also adopt the halfshaft shrouds in 2013.
Moving to the rear of the car and the rendered picture will simply be a placeholder bearing a resemblance to the E20 in terms of diffuser design with the exception being that the exhaust tunnels exit is placed centrally above the perforated diffuser gurney. Once again we have two different designs shown in terms of Rear Wing Endplates with the lower version showing some McLaren-esque strakes. The render showing the rear of the car doesn't show the design of their DRD which will have also likely evolved from the version run in several Free Practice sessions during 2012.
Lotus F1 may well have unveiled their 2013 challenger to the world ahead of their rivals but they certainly haven't given a huge amount away. What we can take away from the rendered and physical images of the E21 though is that the car is clearly an evolution of the E20 featuring push rod front suspension, a sloped nose, unchanged Sidepod inlets and an exhaust solution that will maximise the Coanda effect to gain additional rear downforce (albeit we don't currently know which type).
The leaked images from before the launch as a comparison:
For those asking about the holes around the airbox, these are the lifting points