Maybe seems like a silly post but just wondering what psi people run in there tyres checked my door panel and it reckons I should have 42psi in front and 33 in back I have 59 plate 3 door s3 with 225/40 18 inch tyres just thought it seemed pretty high I've only put 35 psi in them just now scared to put to much in but also don't want to not have enough as I've just put 4 new eagle f1 tyres on oh and it's only usually myself and passenger in car thanks
What psi do you run?
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geefunk1978
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RobbieWebs
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36 all round for me, even wear so far ....
I got 31 front / 30 rear 2.0tdi SE
Doesn't ride feel stiff with 36?
RobbieWebs
Registered User
No m8 not with 18's could probably go to 38 and still feel fine.
Don't know where audi get their figures of 40+ but I'm weary of putting that much into them.
Must admit its a grey area and probably preference what u pump them up to
danb986
In awe of VCDS
I just go with what Audi say on the sticker in the door shut. As I generally only have just me and my wife in the car, I went with the pressures for up to 3 people and 1 suitcase (?). 42 at the front, 36 at the rear in my 225/40x18's. It feels fine, I'm not getting any unusual wear and I get around 60mpg on my 10 mile drive at 60mph on the M1.
Being a diesel, I always assumed the pressures were so high because of the weight of the diesel lump. Although whether that's still true for modern diesels I'm not sure.
Surely running much more than a few psi below the amount on the sticker will affect the mpg?
Michellin reckon that 7psi under the recommended amount is dangerously underinflated. (I think they may be exagerating slightly though).
Check your tyre pressures at least once a month | Care Guide | | Learn and Share | MICHELIN
The AA also say that 8psi underinflated will cost you 10% in mpg. About 5 or 6 mpg in a diesel. Again, this is probably debatable though.
I wish I knew more about tyres, there's so much conflicting information. It sounds like most people on here are running less than what Audi recommend and not experiencing any issues.
Being a diesel, I always assumed the pressures were so high because of the weight of the diesel lump. Although whether that's still true for modern diesels I'm not sure.
Surely running much more than a few psi below the amount on the sticker will affect the mpg?
Michellin reckon that 7psi under the recommended amount is dangerously underinflated. (I think they may be exagerating slightly though).
Check your tyre pressures at least once a month | Care Guide | | Learn and Share | MICHELIN
The AA also say that 8psi underinflated will cost you 10% in mpg. About 5 or 6 mpg in a diesel. Again, this is probably debatable though.
I wish I knew more about tyres, there's so much conflicting information. It sounds like most people on here are running less than what Audi recommend and not experiencing any issues.
The Governor
Registered User
Pay attention to the amount of people it has with the suggested PSI. My car only has me in it 90% of the time and i don't weigh much.
So as an example, it suggests with 3 people and suitcase to run 42 front and 36 rear. Im running 38 all round, I should realistically drop a few psi on the rear but i've never had any problems with it as it is for as long as i've had these tyres and im coming upto 12k on them i think.
I think what should really determine ur psi aside from weight is driving style, i think a higher pressure may prove for lower rolling resistance and a lower pressure for more resistance but maybe better grip because the tyre can compress more into the ground under load. (opinion not fact) What i'd suggest is trying different psi's to see what suits u, trial and error until u find what works
Last edited:
danb986
In awe of VCDS
Note that if you have XL rated tyres fitted - these have re-enforced sidewalls, and have to run at a higher pressure than non-XL rated tyres.
An XL tyre fitment as standard makes sense on a S3. With a low profile tyre, there isn't much of a sidewall. An XL tyre has reinforced sidewalls to cope with the additional lateral cornering dynamics, and enables the tyre to run at a higher inflation pressure to cope.
A non XL 88Y tyre, whilst having a lower static loading, hasn't got reinforced sidewalls!
Interestingly, a XL tyre inflated to the same pressure as a non XL tyre has a lower load capacity. A XL tyre must be inflated to, and run at a higher pressure than a non XL tyre to achieve the same load capacity. This explains why recent 8P's run at 42psi on the front.
Also:
The manufacturer recommended pressure will not necessary tie in with your objectives
Theirs is a compromise figure, for all round workability in a variety of different situations (eg: load, mpg etc).
If you are seeking maximum grip, for example, then a variance of pressure by a few psi will yield the results you are looking for (grip), at the expense of something else (wear).
More info on tyre pressures on A3/S3:
http://www.audi-sport.net/vb/a3-s3-sportback-8p-chassis/184000-best-tyre-pressure-s3.html
An XL tyre fitment as standard makes sense on a S3. With a low profile tyre, there isn't much of a sidewall. An XL tyre has reinforced sidewalls to cope with the additional lateral cornering dynamics, and enables the tyre to run at a higher inflation pressure to cope.
A non XL 88Y tyre, whilst having a lower static loading, hasn't got reinforced sidewalls!
Interestingly, a XL tyre inflated to the same pressure as a non XL tyre has a lower load capacity. A XL tyre must be inflated to, and run at a higher pressure than a non XL tyre to achieve the same load capacity. This explains why recent 8P's run at 42psi on the front.
Also:
The manufacturer recommended pressure will not necessary tie in with your objectives
Theirs is a compromise figure, for all round workability in a variety of different situations (eg: load, mpg etc).
If you are seeking maximum grip, for example, then a variance of pressure by a few psi will yield the results you are looking for (grip), at the expense of something else (wear).
More info on tyre pressures on A3/S3:
http://www.audi-sport.net/vb/a3-s3-sportback-8p-chassis/184000-best-tyre-pressure-s3.html
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Having seen this thread I thought I'd check mine (recently purchased the car). 44 at the front! Given its usually just me in the car I should maybe reduce that a little!
