audi s3 tyre pressures

[cd1969]

can anyone make sense of the tyre pressures on my 2010 s3? the sticker on the inside of the drivers door say 42psi fr and 33rr I havnt a problem with this although 42in the front sounds a bit high. All the tyre garages i have spoke to recommend 30psi allround and every web site ive bin on says 30or31 allround, my problem is, why is there such a big difference in pressures 12psi is a lot of pressure to be down on. Are they higher due to the 4wd?