245/70R19.5 tyres can suit many different trucks. They have 245mm section widths and aspect ratios of 70%. The aspect ratio is a tyre's height in comparison to its width. The R in the code indicates that these tyres are made with radial ply construction, while the following number is the size of the wheel rims that they can fit. For these tyres, it is 19.5 inches.
Tyres have one last aspect at the end of their codes. It is usually two or three numbers accompanied by a letter. These represent the maximum load capacity as well as the highest speed that they can safely reach. For example, a 245/70R 19.5 136M can carry 2240kg for each tyre, at speeds of up to 130km/h.
There is a wide range of trucks that can use 245/70 R19.5 tyres. Whether your vehicle can use them will depend on its make, model and year. There can be slight differences in tyre size between similar trucks, so it is important that you check the correct size before you buy new tyres.
You may find that you prefer other tyres over 245/70R19.5 options. This is because narrower tyres such as the 235/75R19.5 can give you better mileage, as well as a smoother and quieter ride. Wider tyres also have their advantages, because they can give you a shorter braking distance.