From what i have seen the new engines need a lot more air to cool them because of the EGR system. The problem might not have been as bad before but with these new systems there needs to be more air flow. It will be interesting on how the new trucks go with this system i think this is going to become a major problem for manufactures and service companies alike.

All the heat is trapped in the engine compartment and can't get out making the engine over heat , Again because all dust is sucked up from under the truck as the driver moves along this again causes the radiator to get blocked and again goes to the problem of over heating. manufactures are unwilling to spend money on re developing their range because of small market only Europe and North America need them so this problem is only going to get larger