Bus sprites needs help

[masterus]

Hi,
I've resumed work on some sprites I made a few months ago.

Credits for colossal404's Ikarus Set since I loved the way he makes the shading on his sprites.

However I would need some helps, what are the rules concerning the sprites size, is there any rules concerning theirs sizes exetera ?
Especially for articulated bus.. I'm a little bit confused

On those two exemple are the sprites size correct ?

Scania Touring €6 12m.png (4.51 KiB) Viewed 128 times

Scania Touring €6 12m OUIBus

Irisbus Iveco Crossway LE (cough) €5-€6 13m.png (4.41 KiB) Viewed 128 times

Irisbus Crossway €5 13m Arc En Ciel (northern France regional coach services)

Sorry for my bad English

[The Growl]

Well what did you use to make the Sprites. Nice work BTW, could use some more texture though.