Depends whether you want to do it as a business or whether its just for your own vehicles.
I never used to do it as a business only for my own stuff and occasionally helping mates out who had broken down.
Ive had both recovery trucks and trailers and a truck is by far the best imo. If you are collecting cars from around the streets and off peoples driveways etc then a trailer can be a huge headache especially as theres double parking in most residential streets which you will never be able to back a trailer up as you simply wont have the room.
So deffo a recovery truck, and if your license allows (im old so have 7.5t entitlement) buy a 7.5tonner as in the longrun they are more fuel efficient as you dont have to bury your foot through the floor at the slightest of inclines, you can carry more or less any car or van, more reliable with the larger engine and you can easily pull a trailer behind it if needs be so in short you could possibly carry up to 3 vehicles.
If its just your stuff and people you know you can also get away without using a tacho & you dont need an 0 license either.
Other thing which could be handy (which im thinking of) is a lwb luton van which is easy to adapt to take a vehicle (race transporter) get the leaf springs uprated which is not dear, maybe a door fitted to the side and then you have a multipurpose vehicle where you can pick up anything and carry it in safety in the dry which then opens up many more doors if you want to do it as a business.
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