Kinda brings to my mind that it would be worth thinking of giving such vehicles "skill" levels just like normal workers, too. For example:
High-Quality Truck: made in Germany in S / M / L / XL
- breaking down randomly: +0.01% chance/month
- extreme weather problems: 10% chance
- maintenance costs: 1/10
- purchase costs 10/10
- work speed*: 7-10/10
Medium-Quality Truck S / M / L
- breaking down randomly: +0.1% chance/month
- extreme weather problems: 5% chance
- maintenance costs: 4/10
- purchase costs 5/10
- work speed: 4-7/10
Low-Quality Truck in XS / S / M / L
- breaking down randomly: +1% chance/month
- extreme weather problems: 1% chance
- maintenance costs: 10/10
- purchase costs 1/10
- work speed: 1-4/10
Somewhat like this. Just throwing a quick idea onto the table before it's gone.
*EDITED: Depending on size. The machinery as base would be better in the more expensive ones of course.
EDIT2: With well-trained personal you could get somewhat good times on works incl. vehicle even with low-quality vehicle while you could save on spending good personal and just buy good equipment.