Conventional wisdom is that your should increase tyre pressures with increases in load and travelling speed. But in the Arkana’s case, the factory tyre pressure recommendation for either urban or freeway speeds remains at the 33 front and 31 rear psi you’ve noted on your tyre placard. Which suggests that the type of tyre Renault is using is happiest at those pressure regardless of average speed. Which, in turn, suggests that a load that varies only by a couple of passengers and a few pieces of luggage is likewise not going to affect the tyre’s performance. A much better thing to concern yourself with is to keep a weekly eye on the tyre pressures. Tyres lose about one psi a month just sitting around, so keeping on top of that is very important in a safety sense. A tyre can be as low as about 12 psi before it will even look strange to the naked eye, so buy yourself a good quality tyre gauge and get into the habit of checking those pressures every weekend.