There are a lot of posts on this and other websites regarding proper tire pressure. Being a new SQ5 owner I guess I have a newfound interest in this topic, measuring the pressure each month on cold tires as recommended. From what I gather, the best reference remains the sticker on the inside driver door jamb, which should usually match that suggested in the owner's manual (but not always since specs may change between publication of the manual and production of the car, and sticker trumps manual in this case). My own sticker provides information for the 255/40 R21 102Y XL Dunlop Sport Maxx GT summer tires that came with the car (41 PSI Front and 42 PSI Rear; interestingly the manual suggests 41 PSI Front and 36 PSI Rear for the same tire and car specs at normal weight conditions).

My current question stems from the fact that I followed Audi's recommendation for winter tires going to 19" on OEM aluminium wheels, but don't have a reference pressure value for these 235/55 R19 105H Pirelli Scorpion Winters. The manual has a nice table that unfortunately only lists pressure values for summer 21" and summer 20" on SQ5, as if winter did not exist for SQ5 owners (maybe I should be wintering in the Caribbean...). The table also provides values for the Q5. 3 of these are for "high-performance tires", and 2 for "all season tires". The closest match to my Pirelli's is a 235/55 R19 101H "All-Season" which should be inflated at 30 PSI front and 30 PSI rear at normal load conditions, a full 10 PSI below their current state (dealer inflated these to match the summer reference values...). To further confuse me, in the manual's table, 2 identical tires (High performance 255/45 R20 101W) should be inflated at 29 PSI on a Q5 and a full 10 PSI higher at 39 PSI on the SQ5, suggesting Q5 references may not hold for the SQ5.

My dealer tells me to simply follow the door jamb whatever the tire specs... This doesn't make sense to me since the manual provides different reference values for 21" vs 20", so I'd expect 19" should not match the 21" reference values...

Has anyone received shipment of an SQ5 on 19" winter rims to provide the recommended inflation pressures for 235/55 R19 105H tires?

 

So I got a call back from the dealership service today suggesting I let some air out and take them down to 33PSI (currently at 40PSI which is what they set when they installed them). I had fired an email off to Audi Canada 1 week ago figuring that since I had followed all their recommendations for winter wheels and tires for SQ5 they should have some "company line" recommendations for inflation pressure? No response yet...

 

So I emailed Audi Canada with the question... Twice... No reply. Others on international sites have the same problem. Maybe Audi just has no clue? Would be good of Audi to clarify what the optimal tire pressure is on their recommended 19" winter tires on their recommended winter wheels for the SQ5. Since this information does not show up on Pillar B (driver side door jamb) or in the manual as the SUV comes delivered with 20" or 21" rims/tires... I think I'll send a good old typewritten letter by snail mail and give them 30 days for a reply before I send the question to Transport Canada.