My employer told me off for logging time spent driving company vehicle.

So I got an email from my employer about logging hours for driving the company truck.

The email states that they don't compensate for time spent driving to and from work. Which is usually the case, no problems there.

Now the problem I find is when I get up early to drive out of my way to go pick up their truck to drive it to their work site, should I be on the clock when I pick their truck up or when I get to site?

Then the next question should I be on the clock when I leave site at the end of the day to return the company truck to their place?

Lastly when Im using my own personal vehicle Should I be on the clock when I pick up materials to take to site? Bearing in mind I don't get compensation for fuel and Ks for use of my personal vehicle , which seems to be treated as a company vehicle.

My view is that when I drive from my house to work and back it's in my own time. When I've been told to pick up the truck or materials once I pick up that truck or materials (some times both) I'm on the clock. And at the end of the day when I've been told to return the truck I'm on the clock.

Am I right?