What qualifies as a "good truck"?

In one of the patch notes of Euro Truck Simulator 2 I have found the following:

Hired drivers are more efficient when equipped by good truck

I couldn't find any specification for this statement online.

What exactly is a "good truck" and which stats make it such? Does a large cabin increase productivity? Does a bigger chassis help or simply more Horsepower?

Solution 1:

According to everything I could find on this, the more you upgrade your truck, the more efficient they will be. A "good truck" is just a more upgraded or better truck than the one they have currently. Some sources that seem to back this up.

so if you cheap out and give them a lower end truck then they can not work as hard!

source

I had a driver in a 310hp Stralis, and I upgraded it to the 560, and they've had an increase in revenue.

source

Solution 2:

After doing some testing with various trucks of different upgrades, it seems any upgrade to the truck increases driver revenue, I'll have to do more testing later but it doesn't seem like the type of upgrade matters, just how it affects the trucks stats/cost.