Wouldn't a change of the wheelbase require completely new or at least heavily modified suspension, changing many aerodynamical parameters resulting in a different airflow? I doubt teams will still fiddle with their wheelbase at this point bearing in mind their current problems with implementing the power unit, the changed wing sizes and the no longer allowed beam wing. It took Lotus a few races to bring a car with a longer wheelbase last year due to the complexity of this task, so it's rather unlinkely the teams will change the wheelbase with only 40 days to go. I think the wheelbases and aero concepts have been fixed quite some time ago.
On topic: I've redone the comparison in two different ways with the high res pics, the white circles all have the same diameter for front and rear, the rear wings all have the same size
method1: aligning them on the rear axle using the center of the white circles as reference
https://dl.dropboxusercontent.com/u/141 ... temp2t.jpg
Ferrari .... 3498 mm ....
Mercedes . 3528 mm ....
McLaren .. 3520 mm ....
Williams .. 3563 mm ....
Caterham . 3537 mm ....
F. India .... 3464 mm ....
method2: tried to determine where the axle is on the middle of the car, trying to eliminate the influence of the perspectve)
https://dl.dropboxusercontent.com/u/141 ... ttempt.jpg
Ferrari .... 3454 mm ....
Mercedes . 3475 mm ....
McLaren .. 3454 mm ....
Williams .. 3488 mm ....
Caterham . 3459 mm ....
F. India .... 3411 mm ....
that method brought them all very close together into a 3,4 meter range ... i just provided the links because it seems unneccessary to post more pics (two sets should suffice
) ... the old conclusion still stands