Facelift Tyre Pressures on 235/35/R19 Saloon

[HulkRS3]

Got an indicated loss of tyre pressure pop up for the front left on the virtual cockpit earlier, took it to the machine to blow it up and it was sitting at 31.. it did look soft but I'm sure it hadn't been like that all day so I was worried it was a deteriorating puncture.

Anyway... according to the plaque on the door, the lowest pressure for the same tyre size for like 3 people in the car was 39psi!! This seems like quite a lot for a low profile tyre. Did I read it wrong or seemingly normal?

 

[davc]

Hello mate, XL or extra load tyres need higher pressures. I run 42 front and 39 rear this is what the sticker on my car says for 3 people 235/35/19 XL.

 

[Flying Scotsman]

The sticker on Canadian S3 saloons is 44psi on all four tyres, regardless of load factor. Audi have been all over the map on tyre pressures on the S3 saloon with 235/35/19 XL tyres since 2015, some stickers are 39 front and 36 rear for 3 passengers, 42 fully loaded. I personally run 40 front 37 rear with 2 passengers, and I check the pressures every 2-3 weeks with a high quality analog 3" dial pressure gauge, and at that time, dependant on ambient temperature on cold tyres, the pressure normally has dropped 1- 1.5 psi on all four tyres
I personally believe, especially for the North American market the 44 psi sticker is to err on the side of safety, as people generally are very lax on checking tyre pressures, and if they do, they may check when the tyre is hot, rather than cold.

 

[Daveotto]

What @Flying Scotsman says

Mainly single driver so run 40 front 38 rear and check tyres every couple of weeks, or more frequently if I do a lot of miles.

Have my own digital tyre pressure gauge and compressor and although I have a space saver wheel always carry a can of tyre weld in case I get a puncture as would not change a tyre alone on a busy dual carriageway or motorway

 

[A.ShawnS3]

39psi front, 36 rear, 1 + 1 passenger mostly. No issues with uneven wear

 

[Svenedin]

I just use the recommended pressures and have not had problems (but I have 18" wheels). According to the sticker on the car this is same pressure as for 19". Winter tyres (M+S, mud and snow) need higher pressures. The pressures for my Sportback may differ from saloon, I don't know. I keep a foot pump next to the spare wheel (this one: https://gb.michelin-lifestyle.com/en/michelin-digital-double-barrel-footpump). It conveniently fits under the boot floor. I also keep a torque wrench and a deep socket for the wheel bolts in there (using a deep socket keeps the handle of the torque wrench away from the bodywork a bit). I have a tyre tread depth gauge in the glovebox. Correct inflation of tyres is very important for both safety and tyre life. Under-inflated tyres get hot (it increases rolling resistance, the tyre deforms as it rolls) and can blow out with prolonged high speed use (e.g. on a motorway). Over my 28 years as a driver 2 of my friends have had blowouts at speed from haphazard (non-existent) maintenance and they are lucky to be around to tell the tale.

 

[Flying Scotsman]

As per @Daveotto I also have a 12V compressor which I keep in the boot. It has a self contained digital pressure gauge, but it is inaccurate... sets high by 2psi most of the time, when the ambient temperature is above 15 C. My trusty calibrated analog dial pressure gauge corrects that.