[Z4 Beemer]

Ok, the label at the drivers door opening says that for my 18" wheels, carrying two people and no luggage, with 90 W rated tyres, which they are, the front tyres should be 2.3 bar and the rear 2.4 bar.

First question is, am I reading the label correctly?

I never carry much luggage so this seems the reasonable figure to follow.

and secondly, I think I multiply this by 14.5 to get the figured in PSI.
That would mean the front should be 33.35 (rounded to 33) and the rear 34.8 (rounded to 35). Can anyone confirm this? I think its about time I checked the pressures and set them correctly.

[dxb335d]

Originally Posted by Z4 Beemer

Ok, the label at the drivers door opening says that for my 18" wheels, carrying two people and no luggage, with 90 W rated tyres, which they are, the front tyres should be 2.3 bar and the rear 2.4 bar.

First question is, am I reading the label correctly?

I never carry much luggage so this seems the reasonable figure to follow.

and secondly, I think I multiply this by 14.5 to get the figured in PSI.
That would mean the front should be 33.35 (rounded to 33) and the rear 34.8 (rounded to 35). Can anyone confirm this? I think its about time I checked the pressures and set them correctly.

yes you are right, ots 14.7 to be exact i think i aint 100% tho



i had same thing earlier lol

[vivekk]

Originally Posted by Z4 Beemer

Ok, the label at the drivers door opening says that for my 18" wheels, carrying two people and no luggage, with 90 W rated tyres, which they are, the front tyres should be 2.3 bar and the rear 2.4 bar.

First question is, am I reading the label correctly?

I never carry much luggage so this seems the reasonable figure to follow.

and secondly, I think I multiply this by 14.5 to get the figured in PSI.
That would mean the front should be 33.35 (rounded to 33) and the rear 34.8 (rounded to 35). Can anyone confirm this? I think its about time I checked the pressures and set them correctly.

Sounds about right Gordon.

Figures for my 18" Bridgestones work out at 36psi fronts & 42psi on the rears.

Luckily, I checked the pressures before the UK3 meet & they were all about 70%.

You'll certainly notice a big difference after filling them to the correct pressure.


All the best.

Viv

[EVOgone]

42psi - thats not right.!

[vivekk]

Originally Posted by EVOgone

42psi - thats not right.!

I thought it was a little excessive for the rears, but the info speaks for itself.

The info is on a printed plate on the driver's door side panel- NOT in the handbook.

For my car:
Upto a max 4 passengers:

Front 225/40 R18 88W - 2.5 bar - 36.3 psi
Rear 255/35 R18 90W - 2.8 bar - 40.6 psi (I knocked it up to 42!)


Upto a max 5 passengers + luggage:

Front 225/40 R18 88W - 2.8 bar - 40.6 psi
Rear 255/35 R18 90W - 3.2 bar - 46.4 psi


I checked with BMW UK before filling the tyres the first time after I got the car & they told me that they are the recommended pressures for my particular model with those particular tyres.

You can certainly tell that the ride is improved, after checking the pressures.

All the best.

Viv

[Z4 Beemer]

Ahhhhh, of course you would be able to carry 5 people in total. My plate basically says max 2 people or 4 people and luggage.

Originally Posted by vivekk

I thought it was a little excessive for the rears, but the info speaks for itself.

The info is on a printed plate on the driver's door side panel- NOT in the handbook.

For my car:
Upto a max 4 passengers:

Front 225/40 R18 88W - 2.5 bar - 36.3 psi
Rear 255/35 R18 90W - 2.8 bar - 40.6 psi (I knocked it up to 42!)


Upto a max 5 passengers + luggage:

Front 225/40 R18 88W - 2.8 bar - 40.6 psi
Rear 255/35 R18 90W - 3.2 bar - 46.4 psi


I checked with BMW UK before filling the tyres the first time after I got the car & they told me that they are the recommended pressures for my particular model with those particular tyres.

You can certainly tell that the ride is improved, after checking the pressures.

All the best.

Viv

[vivekk]

Originally Posted by Z4 Beemer

Ahhhhh, of course you would be able to carry 5 people in total. My plate basically says max 2 people or 4 people and luggage.

So....does that answer your question then, Gordon?

All the best.

Viv

[simonbenn]

This does seem very high but I guess adjustment for RFTs is required.

Can someone post a pic of the label with their model no?
I guess the pressures are different for the oil burners amongs us.

Thx

Simon

[vivekk]

Originally Posted by simonbenn

This does seem very high but I guess adjustment for RFTs is required.

Can someone post a pic of the label with their model no?
I guess the pressures are different for the oil burners amongs us.

Thx

Simon

No problem Simon.

The RFTs do need relatively high pressures, due to their very nature.

This is for my E90 saloon 330i SE Sports suspension with 18" RFT Bridgestones.

Viv

[Z4 Beemer]

Your pic seems to show 2 men and 2 women... I didn't notice that on mine! I'll need to check it out!

I wanted to check my tyres at the petrol station this morning, but the weather was just terrible. I'll get them sorted next weekend.

Gordon.

[red-max]

Originally Posted by simonbenn

Can someone post a pic of the label with their model no? I guess the pressures are different for the oil burners amongs us.

Here's mine (E92 335d Coupe):

[Z4 Beemer]

and mine: 325i E92

Looks different to the one for the E92 335d

[Z4 Beemer]

Actually, what speed rating are your tyres red-max?

Mine are:

225/40 R 18 W front
255/35 R 18 W rear

(W being the speed rating)

[red-max]

Originally Posted by Z4 Beemer

Actually, what speed rating are your tyres red-max?

Mine are:
225/40 R 18 W front
255/35 R 18 W rear

Supplied from the factory on Star-spoke style 189 (8J x 18/8.5J x 18), I've got Bridgestone Potenza RE050A* tyres:
225/40 R18 88W front
255/35 R18 90W rear

They've all got about 4mm of tread left after just over 10K miles.

[Z4 Beemer]

So for two people in car, your pressures are 2.6 front and 2.8 rear? Strange such a difference as mine are same tyres/wheels and the recommendation is 2.3 front and 2.4 rear!