Gidday Newmax - I had a Hilux, they're a good 4x4. However I clearly recall that your 4x4 mode is not for the black stuff.
What I've discovered over the years is that there's lots of different 4x4 set-ups. I now have a Pajero and it's set-up allows it to be driven in 4x4 on the bitumen and 4x4 is actually recommended when towing. But even Pajero people argue about the benefits of that.
For you and your Hilux though leave the 4x4 for when off the black stuff (gravel, mud, sand) and you should enjoy many happy years of travelling about.
Cheers - Wayne
PS If you're new to 4x4 driving and off roading, then I'd recommend learning a bit about off road tyre pressure. There's good info on the internet & You Tube.
Happy trails