18-19 RS5, what tire pressures with 275/30x20

[dpcompt]

What tire pressures are you guys running with the stock summer tires? Just curious. I'm at 37f, 32r, cold. Mine is a coupe.

[vsaudi]

38/32. Sportback


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[303 Spartan]

37.5 all around. I should probably deflate the rears a bit.

[RS5fvr]

Coupe/Continental summer tires 38F/34R....seems to be the sweet spot for me.

[A U D I]

It really depends on the wheels you are using to be correct

[Valentino S5]

That’s the same pressure I set my tires. The sticker on the door recommends front tires to be at least 36 psi and up to 39, and rear from 30 and up to 38, according to load and number of passengers. I almost always driving alone, so 38/32 seems to be the sweet spot on my Coupe.

[jonpark]

F:38 R:36 for me

[the4siswickid]

F: 37 / R: 34

Obviously, tires run hotter when under load and I've been watching my temps now that I've done the direct TPMS retro.
I might now need to modify.

[Dan99]

What tire pressures are you guys running with the stock summer tires? Just curious. I'm at 37f, 32r, cold. Mine is a coupe.

As you know, the manual provides different pressures for Full load (4+ passengers) and partial load (<4 passengers). For the RS5 SB the partial load figures are 38/32 and these pressures worked fine for me with the stock Continental SportContact6 tires; although 39/32 was better on the track. However, after switching to Michelin PS4S I found the handling to be affected in a negative way by those pressures. I ended up with 41/35 and handling in curves is neutral. If I want more oversteer I can go to 41/36; if I want more understeer I use 41/34.

Some of this was trial and error, but I also used a pyrometer to find pressures that provided even temps across the tire surface after driving hard on curves. So, I suspect the best tire pressure may vary with the specific tires you are using and whether you are more interested in straight line performance or handling in curves.

[kmarei]

What tire pressures are you guys running with the stock summer tires? Just curious. I'm at 37f, 32r, cold. Mine is a coupe.

I have what Audi says they should have for 2 passengers
39 front and 35 rear
But I adjust them when it’s around 70 degrees
If it’s in the 80s I add 1psi front and rear
If it’s in the 90s I add 2 psi front end rear

[303 Spartan]

As you know, the manual provides different pressures for Full load (4+ passengers) and partial load (<4 passengers). For the RS5 SB the partial load figures are 38/32 and these pressures worked fine for me with the stock Continental SportContact6 tires; although 39/32 was better on the track. However, after switching to Michelin PS4S I found the handling to be affected in a negative way by those pressures. I ended up with 41/35 and handling in curves is neutral. If I want more oversteer I can go to 41/36; if I want more understeer I use 41/34.

Some of this was trial and error, but I also used a pyrometer to find pressures that provided even temps across the tire surface after driving hard on curves. So, I suspect the best tire pressure may vary with the specific tires you are using and whether you are more interested in straight line performance or handling in curves.

I just switched to PS4S, myself. I'll give the 41/35 setup a try. Thanks for the info!


However, the real question is... do you guys just rely on your MMI tire pressure read-out, or a physical tire pressure gauge?

I ask because I picked up a digital tire pressure gauge to check pressures and make adjustments and I was surprised to discover that the MMI consistently reads ~3 PSI lower than the physical tire pressure gauge. Thinking that the digital pressure gauge might be faulty, I grabbed one of my older mechanical gauges and got the same results (MMI reading ~3 PSI lower). Granted, this is with aftermarket TPMS sensors from Discount Tire, fitted to my new wheels/tires. So I suspect that might be the culprit.

[2019RS5Sportbak]

I have a really good MotionPro race tire gauge, and the MMI reads much differently. Most specifically my right front is consistently reading lower on the MMI. I cross-referenced with an old analog gauge that reads closer to the MotionPro. I sure hope the MMI is accurate.

[303 Spartan]

Yeah, compared to my digital gauge, my MMI reads exactly 3psi lower on all 4 tires. Regardless of whether the tires are cold or hot.

Now I'm thinking this is a built in safety measure, implemented by Audi to provide a "buffer" once the low tire pressure warning is triggered, buying you more time to reach the next destination and fix the problem.

[Jprieur]

As you know, the manual provides different pressures for Full load (4+ passengers) and partial load (<4 passengers). For the RS5 SB the partial load figures are 38/32 and these pressures worked fine for me with the stock Continental SportContact6 tires; although 39/32 was better on the track. However, after switching to Michelin PS4S I found the handling to be affected in a negative way by those pressures. I ended up with 41/35 and handling in curves is neutral. If I want more oversteer I can go to 41/36; if I want more understeer I use 41/34.

Some of this was trial and error, but I also used a pyrometer to find pressures that provided even temps across the tire surface after driving hard on curves. So, I suspect the best tire pressure may vary with the specific tires you are using and whether you are more interested in straight line performance or handling in curves.

Funny you mention the handling being negatively affected after installing the PS4S. I went the same route on my previous B9S4 after the stock Contisport 6 wore out, and I felt the same. Overall the front end response was just 'off'

I've been a fan and user of the Pilot Sport line for years, and I have even gone so far as to remove brand new Audi tires (hankooks) right after purchasing to get a set of Michelins on. We have the PS4s on the TTS and they were an improvement over the OEM hankooks, admittedly not a hard feat in my book. I was not, however, a fan on them on the B9, as they ruined the front end feel for me. I will say no tire in this class lasts as long as the Michelin PS4S. The only negative on the Contisport 6 to me is the well known treadwear, which is far from good.

RS5 Coupe, I am running 36.5F/33R - so far happy with this (usually just me and the wife in the car, no additional weight)

To those that have gone from OEM contisport 6 to PS4S, curious if road noise changed at all? Contisport has the Contisilent foam, where as the standard PS4S in this size does not (although the TO/Tesla Spec version does have the Michelin Acoustic tech, just not sure what else they changed).

[303 Spartan]

To those that have gone from OEM contisport 6 to PS4S, curious if road noise changed at all? Contisport has the Contisilent foam, where as the standard PS4S in this size does not (although the TO/Tesla Spec version does have the Michelin Acoustic tech, just not sure what else they changed).

I just switched from the 275/30/20 Contisport 6 (@3800miles) to 285/30/20 PS4S. I only have about 20 miles on the new tires, so far. But tomorrow we're leaving for a 250 mile round-trip into the mountains, for a couple of days. I'll report back with my thoughts, afterwards.

[Dan99]

I just switched to PS4S, myself. I'll give the 41/35 setup a try. Thanks for the info!


However, the real question is... do you guys just rely on your MMI tire pressure read-out, or a physical tire pressure gauge?

I ask because I picked up a digital tire pressure gauge to check pressures and make adjustments and I was surprised to discover that the MMI consistently reads ~3 PSI lower than the physical tire pressure gauge. Thinking that the digital pressure gauge might be faulty, I grabbed one of my older mechanical gauges and got the same results (MMI reading ~3 PSI lower). Granted, this is with aftermarket TPMS sensors from Discount Tire, fitted to my new wheels/tires. So I suspect that might be the culprit.

Use a physical gauge. The TPMS only displays increments of 1.5 psi. So, for example, when I set my tires to 41/35 the TPMS shows 40.5/35. Also, you have to set pressures when the tires are cold and the TPMS only registers changes when you drive, which warms up the tires.

So, trust the tire pressure gauge over the TPMS, but pressure gauges are notoriously inaccurate. I spent extra to get an accurate one ( http://www.longacreracing.com/produc...Gauge-0-60-psi ). The same site has many others, but you don't have to go to that extreme unless you want (see pictures below).

Also, the 41/35 is for an RS5 SB. If you have the coupe it may be different. The manual says 38/32 for my car, and the oem Continentals worked well at that pressure. However, the PS4S did not work so well and handling was worse than the Continentals. I watched the amount of sidewall scrub (see pictures below), then eventually used a pyrometer ( http://www.longacreracing.com/produc...Tire-Pyrometer ) to figure out what was going on. The PS4S had high temps at the edges of the tires and cooler temps in the center of the tread. This indicates under-inflation ( http://www.longacreracing.com/techni...ll%20a%20Story ). Apparently the PS4S has stiffer sidewalls than the Continentals. I increased tire pressures until the temperatures equalized across the full width of the tread. In my case, I added 3psi to front and rear, maintaining the recommended 6psi front/rear differential.

You can accomplish most of this without a pyrometer, using a bit of trial and error. All performance tires have some type of indicator to help determine if your tires are inflated correctly for your car. Drive the car on curvy roads, expressway ramps, etc. so that you are turning aggressively, then look at the scrub line on the sidewall relative to the marker. You can even put chalk on the tire before driving to get a better sense of where the sidewall scrub is after you make a pressure adjustment. Ideally, the scrub will reach the top of the marker on each tire.


Here is a photo of the rear PS4S at 35 psi. The scrub line is right on the top of the marker:

TirePressureRear-33.jpg


Here is a photo of the front PS4S at 41 psi. The scrub line is slightly over the top of the marker:

TirePressureFront-33.jpg

[Dan99]

Funny you mention the handling being negatively affected after installing the PS4S. I went the same route on my previous B9S4 after the stock Contisport 6 wore out, and I felt the same. Overall the front end response was just 'off'

I've been a fan and user of the Pilot Sport line for years, and I have even gone so far as to remove brand new Audi tires (hankooks) right after purchasing to get a set of Michelins on. We have the PS4s on the TTS and they were an improvement over the OEM hankooks, admittedly not a hard feat in my book. I was not, however, a fan on them on the B9, as they ruined the front end feel for me. I will say no tire in this class lasts as long as the Michelin PS4S. The only negative on the Contisport 6 to me is the well known treadwear, which is far from good.

RS5 Coupe, I am running 36.5F/33R - so far happy with this (usually just me and the wife in the car, no additional weight)

To those that have gone from OEM contisport 6 to PS4S, curious if road noise changed at all? Contisport has the Contisilent foam, where as the standard PS4S in this size does not (although the TO/Tesla Spec version does have the Michelin Acoustic tech, just not sure what else they changed).

The Michelins are typically not noisy, but occasionally they make a LOT of noise on some concrete highways. The Continentals were quiet and did not make the same odd noise as the Michelins.

I have been a fan of Michelin for years and went right to the PS4S when I needed tires. I sorted out the issue with the tires and just described that in another post. It appears that the Michelins have stiffer sidewalls which require more air pressure to keep the center of the tire in full contact with the road. See my previous post.

[303 Spartan]

...

You can accomplish most of this without a pyrometer, using a bit of trial and error. All performance tires have some type of indicator to help determine if your tires are inflated correctly for your car. Drive the car on curvy roads, expressway ramps, etc. so that you are turning aggressively, then look at the scrub line on the sidewall relative to the marker. You can even put chalk on the tire before driving to get a better sense of where the sidewall scrub is after you make a pressure adjustment. Ideally, the scrub will reach the top of the marker on each tire.


Here is a photo of the rear PS4S at 35 psi. The scrub line is right on the top of the marker:

TirePressureRear-33.jpg


Here is a photo of the front PS4S at 41 psi. The scrub line is slightly over the top of the marker:

TirePressureFront-33.jpg

This is fantastic information. Thank you for sharing. I never knew/cared about a "scrub line", until now. I have the RS5 SB and PS4S set to 35/40 using a manual gauge. I'll monitor the scrub line and use that to help determine if I need more/less air.

Also, I just put ~250 miles on the new PS4S and even my wife noticed that the PS4S "sounded quieter" than the OEM Conti's. But at 285/30/20 it is a wider and slightly taller tire, so I'm sure that plays into it. However, I will 2nd your comment that on some random highway surfaces, the PS4S's produce a more audible "humming" that I never heard from the OEM tires.

[vsaudi]

Yeah, compared to my digital gauge, my MMI reads exactly 3psi lower on all 4 tires. Regardless of whether the tires are cold or hot.

Now I'm thinking this is a built in safety measure, implemented by Audi to provide a "buffer" once the low tire pressure warning is triggered, buying you more time to reach the next destination and fix the problem.

TPMS pressures displayed are 3psi lower than gauge on mine too


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