HalfGerman

Anyone have a pic of the Euro tire pressure sticker to compare with the US one.

On my Golf R the US sticker simply lists one set of pressures. Which is full load on the EU sticker, they also have half load pressure listed.

NC TRACKRAT

Too many variables like tire manufacturer, tread and compound, type of driving, temperature, road conditions, etc. Best to let your sphincter tell you what feels best.

JParanee

17’s or 18’s 34# rear 32# front COLD

people run to much pressure in their tires car and bike

Greg Bell

When I purchased my C2 it had 16" wheels running 40psi. I now have 17" wheels and do 35psi all round. 40psi is too high for the roads in North Queensland. Each to his own.

My daily driver is a late 2022 Volvo XC40 T4 with 19" wheels. When I picked up the car I asked what the pressure was set at to be told 40psi. The dealer said a little higher wears a lot better and the Michelins are very grippy.

I was quite pleasantly surprised at how good the ride was at 40psi on 19" wheels. If I put 40psi in my C2 I would probably need to wear a kidney belt - the roads here are atrocious.

So the takeaway from this is - horses for courses - set your tyre pressure according to the tyre, your driving style and of course the condition of the road.

jadatis

Is this what you want.

Churchill

No, it is not. That is not a 993 sticker. This is a 993 forum.

jadatis

I can make you a customised pressure/loadcapacity list for your tires.

Then you " ONLY" have to determine the axleloads in your use 99% acurate, the most tricky part, and your responcibility.

Yust give for what maximum speed, and give tire specifications, if front rear different for both.

​​​​​​1. Maximum load or loadindex
2. Kind of tire to determine the maxloadpressure
Most likely XL /reinforced /Extraload AT 42psi
Standard load AT 36 psi.
3.speedcode, less important, have my own better system for that.

If you dont give wishes, I give 90% of axleloadcapacity for 160kmph/99mph.
Determined this to give maximum reserve, with still acceptable comfort and gripp.
And I calculate with an even saver formula that comes closer to lineair calculation then the official used in Europe for decades, and since 2006 also for P-tires in US.

For the fully loaded, only given on US plates, they give for GAWR's and maximum technical carspeed.
For 3 persons and a little load, the carmaker determined the axleloads.
On old plates sometimes also for upto 160kmph/99mph given, wich is the referencespeed used to calculate the maxload of tires with speedcode Q to V, but in my system, I also use it for W and Y Speedcode.

Using my list, you are doing better then the plate or 3 pages in the manuall.

nk993

Hi Jadatis, that sounds very interesting, thanks for offering. Let's try for these tires, I would be super curious to see the answer:

Tire sizes: Front: 235/40 R18, Rear 285/30 R18

Specs:
1. Service Description: Front 95Y, Rear 93Y
2. Load Range: Front XL, Rear SL
3. Max Load: Front 1356 lbs/615kg, Rear: 1,433 lbs /650kg
4. Max inflation pressure 51 PSI
5. Weight = 23 lbs.

For axleload, not sure I fully understand what you mean, but when I corner balanced the car I had: Front: 555kg, Rear: 848kg

orangecurry

Euro sticker - no load variation.

jadatis

Answer to post 2 up # 23

First checked rear, and XL has loadindex 97, so yes 93 is what you have, thought every low hight/width division tire ( your /30 behind) was XL.

Then here the list for axleweight given, if you want for per wheel weighed, wich I make of cornerbalanced, I can make another list in wich 95% given of loadcapacity for 1 tire, in wich you then look back the heavyest side on axle.

Thought to make it logical, by giving in front of cold psi the KG for frontaxle, and behind the cold psi for behind axle. And because you gave in KG, I also gave in KG, if you want in lbs, I can make another list. Maxspeed to use 160kmph/ 99mph.
Because of the reserves build in, less then a minute a bit higher speed most likely wont give overheated tire, but dont shoot me if it does.

FR 95XL/ cold psi/ RR 93SL
Axleload/ cold psi/ Axleload
550 KG/ 18 psi / 599 KG
577 KG/ 19 psi / 628 KG/ 555kg fr
603 KG/ 20 psi / 657 KG
629 KG/ 21 psi / 685 KG
656 KG/ 22 psi / 714 KG/ EUR lowest
682 KG/ 23 psi / 742 KG
708 KG/ 24 psi / 770 KG
734 KG/ 25 psi / 799 KG
760 KG/ 26 psi / 827 KG/ US lowest
786 KG/ 27 psi / 855 KG/ 848 kg rr
812 KG/ 28 psi / 883 KG
837 KG/ 29 psi / 911 KG
863 KG/ 30 psi / 939 KG
889 KG/ 31 psi / 967 KG
915 KG/ 32 psi / 995 KG
940 KG/ 33 psi / 1023 KG
966 KG/ 34 psi / 1051 KG
991 KG/ 35 psi / 1079 KG
1017 KG/ 36 psi / 1107 KG/rear maxloadpr
1042 KG/ 37 psi / 1134 KG
1068 KG/ 38 psi / 1162 KG
1093 KG/ 39 psi / 1190 KG
1119 KG/ 40 psi / 1217 KG
1144 KG/ 41 psi / 1245 KG
1170 KG/ 42 psi / 1272 KG/ fr maxloadpr
1195 KG/ 43 psi / 1300 KG
1220 KG/ 44 psi / 1327 KG
1245 KG/ 45 psi / 1355 KG
1271 KG/ 46 psi / 1382 KG
1296 KG/ 47 psi / 1410 KG
1321 KG/ 48 psi / 1437 KG
1346 KG/ 49 psi / 1464 KG
1371 KG/ 50 psi / 1492 KG
1396 KG/ 51 psi / 1519 KG/ max allowed cold pressure both

nk993

hmm. Not sure I get this. This chart implies I should be running cold psi of 18 front and 27psi rear?

Twilightblue28A

An example of overcomplicating a simple question.

jadatis

If the 555kg you gave is axleweight front, yes 18 psi, but if weight per wheel front you need about 36 psi.

nk993

That can’t be correct. The weight I gave you is axle weight. A 993 (C2S in my case) weighs roughly 1400kg with 40/60 weight distribution …so the weights are more or less correct

there’s no way 18psi is reasonable

IainM

If I understand jadatis correctly (I’m not clear on this either) 18lb means you can’t corner as this would exceed the design weight and you’d overheat the tire.
the corner case where 100% of the axle load is on one tire = 36lbs which is what’s taken as safe.
For autocross then I would need to use max speed of 80kph and calculate the left/right tire loads with 1G lateral acceleration.
thanks, this is really informative