This article is considered accurate for the current version (1.54) of the game.
This variation of the standard R-5 Hauler is fitted with an improved suspension and axle system resulting in better overall handling. However, these improvements may not hold up under severe weather conditions.
— In-game description
The R-5b “Sisyphus” Hauler is a ColonialTruck designed to be an all-purpose logistics vehicle, capable of moving cargo, equipment, and personnel to various locations, can towField Weapons and Trailers, and possesses a boost capability when pressing Shift. Its most distinctive features are the white rims, and the white roof of the driver's compartment.
The R-5b “Sisyphus” Hauler, like all trucks, are a valuable part of Foxhole's logistical loop in terms of gathering resources and materials, transporting equipment, and delivering/storing them. As such, it is important to have them stored in either a Seaport or a Storage Depot and not lying around in order for partisans to steal them. If you do not plan on storing it there, then make sure it is behind defenses with AI, as parking them in front will block their line of sight, making them unable to shoot targets.
Similar to other vehicles with a speed boost function, constantly boosting will quickly drain the fuel tank. As such, it shouldn't be done all the time, especially in regions where fuel is harder to come by.
Trucks are the only way to get a majority of Foxhole's equipment to the frontline, which comes in the form of crates. As such, they are a vital part of getting large amounts of equipment to a base in a quick and timely manner. They are also pretty fragile, and can quickly be disabled by any weaponry in a few shots. As such, it is very important that there is Map Intelligence covering the roads so any partisans can be preemptively spotted and dealt with by frontline forces.
In terms of what drivers need to carry on them when doing this, they should at the very least carry a rifle and two clips of ammo. This is to defend yourself from partisans and to increase your chances of surviving the encounter. While it is not necessary, you can also equip a Gas Mask and two Filters to protect yourself from Gas Grenades.
The name refers to the Greek legend Sisyphus, who was the king of Ephyra.
He was cursed to roll a big boulder up a hill, only for it to roll down every time he reaches the top, having to repeat this task for eternity.
The R-5b “Sisyphus” Hauler is currently the only truck that has a boost function. Initially, the boost function was minimal, which did not give it much utility, but this was buffed in Update 1.54 ('Naval Warfare'), which buffed the boost function and made it way more noticable.