Id have thought around 36/38 on the rear with that much weght. Under filling them when running with lots of weight will kill the tyres off quicker than running over filled.

 

i drive most days with a family of 5, an average sized wife, 3 kids under 4 a double buggy and a single buggy in boot at all times + or - shopping. what would you recommend i set my tyre pressures too? as you will have noticed there is a massive difference in full load and normal load pressures in users manual. i have been running them as full load but don't want to prematurely age my tyres. p.s kwik fit's online pressure check guide recommends -
Tyre SizeFront (BAR)Front (PSI)Rear (BAR)Rear (PSI)225/45W172.2 BAR31 PSI2.2 BAR31 PSI225/40W182.6 BAR37 PSI2.4 BAR34 PSI

totally different from user book!!???

For that load I'd use the normal pressures from the owners manual - that's not enough load to use fully laden - and you can't trust anyone else's figures.