Tyre pressure on 225\40\18

[redlabel81]

Anyone with some insight on what pressure I should run on my 225\4018 tyres? Avant.

[CBRmatt600]

What is a tyre?

[elwigglero]

The max PSI should be right on the side of the tire

[CBRmatt600]

And the manufacturer recommended pressure is always on the inside of the drivers door.

[Glassnpowder98]

What is a tyre?

That's what some people call it who aren't from YOUR country... Like how Canadians say colour instead of color.

To answer the OP's question, the inflation numbers should be on the inside of the driver's door. Those numbers are the recommendation for all tire sizes as that pressure is ideal for the weight of the car to ensure the best contact patch between the tire and the road. Off the top of my head, I can't remember the numbers, but I think it's 35psi up front and 33psi in the rear.

[redlabel81]

What is a tyre?

Thanks!
UK = Tyre, USA = Tire

[redlabel81]

Thanks for the informativ info guys.
I know about the info on the inside of the door, but talked to the tyre dealer and he recommended me to drive with higher pressure than that. Closer to 40PSI.....Think it sounds high.

[Glassnpowder98]

The only time I've heard of people running 40psi is when they're at the drag strip with a lower horsepower car trying to get the tires to spin a little off the line... I would stick with the recommended pressure since like I said, it's the "best" pressure to have the "best" contact patch with the road based on the weight of the car. If you're into tweaking things and have a good feel for your car and it's handling/braking, you can try different psi's to see if you can feel the car handling differently. Just remember if your pressures are too drastically different from the recommended pressure, you chance killing gas mileage and premature wear of your tires (tyres).

[CBRmatt600]

Thanks!
UK = Tyre, USA = Tire

I seriously did not know that.

And yeah, 40 is way high.

[Glassnpowder98]

You learn something new everyday! Disregard my semi dick comment in my first post...

[CBRmatt600]

Ha I already assumed you didn't realize I was being serious. I obviously knew what he was talking about but didn't know that people actually spelled it that way.

[quattshot]

Anybody with any Autocross or track experience can tell yah that knowing what tire pressure is good for your conditions is an art in itself. Since tire pressure can induce under and oversteer by adding (+-) PSI in the front and back, you can actually play with your PSI from front to back. For everyday driving I would use the recommended tire pressures on the inside of your door jam as a REFERENCE. Play with it from there. REMEMBER, if you lowered your car, your camber will be thrown off a bit and the inside of your tires will wear faster. Therefore, try and keep a bit more air (PSI) in your tires to TRY and keep most of the rubber in the center of the tire in more contact to the tarmac. If you keep less air, then the inside of your tires will scrub more and wear even faster with a lowered car.

Always remember from a cold start, once your tires come up to temperature (which could take 5+ minutes depending on what type of driving your doing), your air pressure will INCREASE by at least 3 PSI!! So, keep that in mind when filling your "COLD" tires to a MAX of 40!! You dont want your tires to SKIP over bumps, potholes, etc. You want the tires to absorb these obstacles keeping the rubber DOWN on the ground.

Me personally, I like 32-35 psi for 18's.

[EuroA4]

With all the above in mind, I have mine at 38-40 too. 40 can be a bit much, but I drive alot on the hwy and over NJ roads which suck...so sometimes 40 is more for safety then performance. Bending wheels sucks !

[redlabel81]

Anybody with any Autocross or track experience can tell yah that knowing what tire pressure is good for your conditions is an art in itself. Since tire pressure can induce under and oversteer by adding (+-) PSI in the front and back, you can actually play with your PSI from front to back. For everyday driving I would use the recommended tire pressures on the inside of your door jam as a REFERENCE. Play with it from there. REMEMBER, if you lowered your car, your camber will be thrown off a bit and the inside of your tires will wear faster. Therefore, try and keep a bit more air (PSI) in your tires to TRY and keep most of the rubber in the center of the tire in more contact to the tarmac. If you keep less air, then the inside of your tires will scrub more and wear even faster with a lowered car.

Always remember from a cold start, once your tires come up to temperature (which could take 5+ minutes depending on what type of driving your doing), your air pressure will INCREASE by at least 3 PSI!! So, keep that in mind when filling your "COLD" tires to a MAX of 40!! You dont want your tires to SKIP over bumps, potholes, etc. You want the tires to absorb these obstacles keeping the rubber DOWN on the ground.

Me personally, I like 32-35 psi for 18's.

Great post. Thanks. I'm thinking I will stick with the recommended value for now and maybe add some when lowering her.
So the recommende tyrepressure as stated inside the door is that when the tyre is warm or cold?

[a4audi4fun]

Great post. Thanks. I'm thinking I will stick with the recommended value for now and maybe add some when lowering her.
So the recommende tyrepressure as stated inside the door is that when the tyre is warm or cold?

Based upon a cold tyre (usually less than 1 mile / 1.6km of driving). If you can't get to a pump within approx that distance, measure the pressure before starting the car. Once at the air pump, measure pressure again and allow for the increased pressure from a warm tyre. Check the next morning that you got it right; repeat as necessary

[Maverik869]

only car I have ever known was a Mk4 R32 asking to Run 40+ psi in the rear tires from the Factory!

[wayneB7]

What is a tyre?

European tires are tyres. They offer better performance on European cars like Audis. That should be the first upgrade we do to our cars -- ditch the crappy tires and get tyres. Next, do the sway bar and then drop the car, etc ...

(Just playing with ya ...)

[wayneB7]

Anyone with some insight on what pressure I should run on my 225\4018 tyres? Avant.

I like 35 psi ... just a tad above the recommended pressures on the door jamb. BTW, the sticker pressures are the pressures that are used in the design calibrations of the car's suspension (the tire is just another spring) so you'd probably find that staying close to the spec pressure is best. Over a tad for nicer feel and better fuel economy.

[cecaa]

I would do 38 for 18". My 19" is on 40 psi all around.

the sticker on the door panel actually states different psi for different tires, therefore I think the ideal psi for maximum road contact should be different depending on the diameter/width/sidewall and maybe even the brand of tires (different materials /sidewall support).

The camber also makes difference when deciding the pressure, not big difference tho.

[milotron]

The decal on the doorsill of my 2006 2.0t sline says 41 psi for the 235/45/18s.

[quattshot]

Great post. Thanks. I'm thinking I will stick with the recommended value for now and maybe add some when lowering her.
So the recommende tyrepressure as stated inside the door is that when the tyre is warm or cold?

Definitely cold. You will be happy with 38lbs all around. Maybe 40 in the rear to try and dial out that little extra oversteer that we need to compensate for tons of Audi Understeer.

[redlabel81]

^^ Thanks mate.

[EuroA4]

I would do 38 for 18". My 19" is on 40 psi all around.

the sticker on the door panel actually states different psi for different tires, therefore I think the ideal psi for maximum road contact should be different depending on the diameter/width/sidewall and maybe even the brand of tires (different materials /sidewall support).

The camber also makes difference when deciding the pressure, not big difference tho.

Exactly!! I'm running 225/35/19 and 255/30/19 so the extra psi is safer...when they loose pressure and go down to 34-36 they feel too low and get squishy.

[DFDUB.S-Line]

35-40psi