Check you tyre pressures

Waffle · 07-20-2011, 06:49 PM

Thought I would check the pressures for the first time before heading off on a long journey fully loaded. Had expected to add air not lose some.

Based on 19 inch wheels and the tyre pressure table on drivers door opening, unloaded pressures should be:

Fronts 2.0 Bar (were set at 2.5 Bar)
Rears 2.0 Bar (were set at 2.6 Bar)

02420X3 · 07-20-2011, 08:10 PM

For those who don't think in Metric, what Waffle is saying is that his tire pressure should have been set at about 29 Lbs/PSI according to the door sticker, but that his fronts were set at 36 Lbs/PSI and his rears were set at 38 Lbs/PSI.

That will stiffen up the ride a bit...

Nahoa · 07-20-2011, 09:36 PM

Read the manual. It has all the info broken down by speed and passenger/cargo volume.

Lotus7 · 07-20-2011, 11:29 PM

Quote:

Originally Posted by Waffle

Thought I would check the pressures for the first time before heading off on a long journey fully loaded. Had expected to add air not lose some.

Based on 19 inch wheels and the tyre pressure table on drivers door opening, unloaded pressures should be:

Fronts 2.0 Bar (were set at 2.5 Bar)
Rears 2.0 Bar (were set at 2.6 Bar)

The US X3 manual does not specify the correct pressure for a 20d (only the 28i and 35i) but the pressures you quoted sound too low for a "fully loaded" X3 (and the 20d weight is not that different from a 28i).

For a fully loaded NA X3 with 245/45R 19 inch tires the quoted minimum pressures are actually 2.6 bar / 38psi F and 3.0 bar / 44 psi rear.

For a "partial" load, BMW says: "2.2 bar /32 psi F and 2.6 bar /38 psi R.
Going on a long trip "fully loaded" with only 2.0 bar at both ends sounds like a disaster waiting to happen.

I'll second Nahoa's recommendation: RTFM!

sfax · 07-21-2011, 01:12 AM

Quote:

Originally Posted by Lotus7

The US X3 manual does not specify the correct pressure for a 20d (only the 28i and 35i) but the pressures you quoted sound too low for a "fully loaded" X3 (and the 20d weight is not that different from a 28i).

For a fully loaded NA X3 with 245/45R 19 inch tires the quoted minimum pressures are actually 2.6 bar / 38psi F and 3.0 bar / 44 psi rear.

For a "partial" load, BMW says: "2.2 bar /32 psi F and 2.6 bar /38 psi R.
Going on a long trip "fully loaded" with only 2.0 bar at both ends sounds like a disaster waiting to happen.

I'll second Nahoa's recommendation: RTFM!

Waffle quoted unloaded figures and they are correct as per the door sticker for his tyres assuming they're the same as mine (we're both on staggered 309s)

continental sport contact 3 tubeless

275/40 R19 101W rear

245/45 R19 98W front

Pressure, unloaded F2.0 R2.2 to full load F2.2 R2.5 bar (F29, R32 to F32, R36 psi)

ronsil · 07-21-2011, 08:35 AM

How does the recommended pressure change for non runflats? Also, what about pressure for a 22" wheel?

Lotus7 · 07-21-2011, 10:45 AM

Quote:

Originally Posted by sfax

Waffle quoted unloaded figures and they are correct as per the door sticker for his tyres assuming they're the same as mine (we're both on staggered 309s)

Noted, but he mentioned "..expected to add air not lose some." Which implies that he MAY have reduced the pressure to the mentioned values.

In the US, the door jam sticker values are especially misleading, as they only specify the unloaded recommendations, and don't mention the need for increasing pressure with added loading. The sticker does mention that the "combined weight of occupants and cargo should not exceed 415kg", but makes no mention of increasing tire pressures accordingly.

I always set pressures to those that give the best "seat of the pants" steering response feel anyway, and those are usually 2 or 3 psi over the factory recommended values for a lightly loaded vehicle (depending on specific tires).

coiken · 07-27-2011, 06:22 AM

This is the best advice possible for all new X3 owners!!!

Just checked mine, they were set to 3.3 bar(front) and 3.4bar (rear)!!!
I've now lowered it a bit to 2.3 front and 3.4 rear, a world of difference in comfort this is!!!
I wonder if I should drop it even more to 2 bar (front) and 2.2 (rear)

Thanks for the hint Waffle!

Marketor · 07-27-2011, 06:38 AM

What do you guys think using nitrogen to inflate tires (and keep stable pressure)?

LEDZEP · 07-27-2011, 06:51 AM

29 PSI? That is way too low, even for an unloaded X3. I tend to overinflate by 2-3 PSI on all my vehicles, for a few reasons: 1) better fuel economy 2) longer tire life 3) better response and handling.

If you prefer a softer ride, you can stick to the recomended pressures, that's a preference issue. I know here in the U.S. most folks don't check their pressure nearly often enough.

Tire pressure recommendations are made for reasons of safety, performance, and BRAKING. Keep in mind that your braking is also affected by the tire pressure.

Nitrogen - to the question about using Nitrogen, it depends on where you live and the time of year, and your tolerance for cost. It's fairly expensive to have your tires Nitrogen filled (at least it seems pricey to me). I have considered its benefits when fall comes and I know my pressures will be all over the place until spring, but I have a compressor in the garage and check and adjust them regularly. The benefit of N is that it is less volitile and does not expand and contract as much as 'air' does in our atmoshperic range. If adjusting your pressures is not very convinient for you it is something to consider.

sfax · 07-27-2011, 02:17 PM

Quote:

Originally Posted by LEDZEP

Nitrogen - to the question about using Nitrogen, it depends on where you live and the time of year, and your tolerance for cost. It's fairly expensive to have your tires Nitrogen filled (at least it seems pricey to me). I have considered its benefits when fall comes and I know my pressures will be all over the place until spring, but I have a compressor in the garage and check and adjust them regularly. The benefit of N is that it is less volitile and does not expand and contract as much as 'air' does in our atmoshperic range. If adjusting your pressures is not very convinient for you it is something to consider.

And bear in mind air is 78% nitrogen and doesn't cost anything

sfax · 07-27-2011, 02:20 PM

Quote:

Originally Posted by coiken

I've now lowered it a bit to 2.3 front and 3.4 rear, a world of difference in comfort this is!!!

A world a difference between front and rear!

I always go about 0.2 bar above recommended

coiken · 07-28-2011, 04:21 AM

Quote:

Originally Posted by sfax

A world a difference between front and rear!

I always go about 0.2 bar above recommended

LOL, typo... it's 2.3 front and 2.4 rear

cooldude00 · 09-23-2011, 04:15 PM

checked the tyres earlier after collecting the car and they were set at 2.5bar instead of the recommended 2.0.. this is for 225/60/17.

ivanoski · 09-23-2011, 05:28 PM

Cant the Idrive tell you the tirepressure? i cant find the menu option for it...

Razel · 09-23-2011, 05:43 PM

Quote:

Originally Posted by ivanoski

Cant the Idrive tell you the tirepressure? i cant find the menu option for it...

I don't think so. Just indicates good/low on a per-tire basis in the display.

BTW, door sticker says 32F/35R for the 245/50 R18. No mention of increasing due to weight difference. It does recommend 38F/44R if the vehicle is to be driven over 100MPH (if only ...)

When car comes back from the service dept., tire pressures can be anywhere. Worksheet says 32F/35R, but actual pressures usually differ.

sfax · 09-23-2011, 07:17 PM

Quote:

Originally Posted by ivanoski

Cant the Idrive tell you the tirepressure? i cant find the menu option for it...

You have to check the tyre pressure yourself, inflate/deflate if required, and then initialise the tyre pressure monitor straight after (vehicle info on iDrive)

On the 20d the monitor / warning system detects differences in rotational speed between the wheels so if one tyre's pressure drops below the others it will trigger the warning. This does mean they could all go down together gradually over time so you should still check and re-initialise regularly

twistediron · 09-23-2011, 10:12 PM

Quote:

Originally Posted by sfax

And bear in mind air is 78% nitrogen and doesn't cost anything

and if the concern is the oxygen getting out of the tire.. fill it a few times and it will be virtually all nitrogen anyway.

nitrogen is the new dealer snake oil imho

TuffLittleUnit · 09-24-2011, 02:08 PM

Quote:

Originally Posted by sfax

And bear in mind air is 78% nitrogen and doesn't cost anything

My kids tell me that the air around me is 66% methane.

96_Impreza · 09-24-2011, 05:20 PM

Quote:

Originally Posted by TuffLittleUnit

My kids tell me that the air around me is 66% methane.

The "new math" is a gas, gas, gas!

Penso di no · 09-25-2011, 01:05 AM

Quote:

Originally Posted by twistediron

and if the concern is the oxygen getting out of the tire.. fill it a few times and it will be virtually all nitrogen anyway.

nitrogen is the new dealer snake oil imho

The reason pure dry nitrogen is used in racing and aviation is because it expands/contracts less--and more predictably--than air, but it's not because of the oxygen in the air. It's because of the water (vapor).

For normal driving, I'd think just making sure your pressure is up to spec (or a little over) is way more important than what you put in there.

JOHNBMWM5 · 11-08-2011, 06:48 AM

Quote:

Originally Posted by TuffLittleUnit

My kids tell me that the air around me is 66% methane.

After a "Curry" mine could be higher than that.

But still GAS.

07-20-2011, 06:49 PM	#1
Waffle Private 19 Rep 84 Posts Drives: BMW F25 X3 xDrive20d SE Join Date: Dec 2010 Location: UK iTrader: (0)	Check you tyre pressures Thought I would check the pressures for the first time before heading off on a long journey fully loaded. Had expected to add air not lose some. Based on 19 inch wheels and the tyre pressure table on drivers door opening, unloaded pressures should be: Fronts 2.0 Bar (were set at 2.5 Bar) Rears 2.0 Bar (were set at 2.6 Bar) __________________ BMW F25 X3 xDrive20d SE black sapphire \| black nevada leather \| wave wood \| 19" double spoke alloys \| xline \| xenons \| business advanced media package \| electric seats \| dab \| extended storage \| grey shade band \| auto
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07-20-2011, 08:10 PM	#2
02420X3 Captain 63 Rep 983 Posts Drives: 2011 X3 35i Join Date: Jun 2011 Location: Boston iTrader: (0)	For those who don't think in Metric, what Waffle is saying is that his tire pressure should have been set at about 29 Lbs/PSI according to the door sticker, but that his fronts were set at 36 Lbs/PSI and his rears were set at 38 Lbs/PSI. That will stiffen up the ride a bit...
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07-20-2011, 09:36 PM	#3
Nahoa Lieutenant Colonel 45 Rep 1,876 Posts Drives: F25 35i Mineral Silver/Black Join Date: May 2008 Location: Virginia iTrader: (0)	Read the manual. It has all the info broken down by speed and passenger/cargo volume. __________________
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07-21-2011, 08:35 AM	#6
ronsil Second Lieutenant 25 Rep 204 Posts Drives: Black e46 Join Date: May 2005 Location: Canada iTrader: (0)	How does the recommended pressure change for non runflats? Also, what about pressure for a 22" wheel?
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07-27-2011, 06:22 AM	#8
coiken Private First Class 14 Rep 121 Posts Drives: BMW X1 Join Date: Jan 2010 Location: Vlierzele iTrader: (0)	This is the best advice possible for all new X3 owners!!! Just checked mine, they were set to 3.3 bar(front) and 3.4bar (rear)!!! I've now lowered it a bit to 2.3 front and 3.4 rear, a world of difference in comfort this is!!! I wonder if I should drop it even more to 2 bar (front) and 2.2 (rear) Thanks for the hint Waffle!
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07-27-2011, 06:38 AM	#9
Marketor New Member 2 Rep 20 Posts Drives: 2011 BMW X3 35i Join Date: Jul 2011 Location: Canada iTrader: (0)	What do you guys think using nitrogen to inflate tires (and keep stable pressure)?
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07-27-2011, 06:51 AM	#10
LEDZEP Lieutenant General 417 Rep 12,276 Posts Drives: 2009 E70 & 2011 F25 Join Date: Jun 2005 Location: Area 51 iTrader: (0) Garage List 2011 X3 35i M Sport [7.62] 2009 X5 M Sport [0.00] 2007 328xi E90 [0.00] 2006 325xiT E91 [0.00]	29 PSI? That is way too low, even for an unloaded X3. I tend to overinflate by 2-3 PSI on all my vehicles, for a few reasons: 1) better fuel economy 2) longer tire life 3) better response and handling. If you prefer a softer ride, you can stick to the recomended pressures, that's a preference issue. I know here in the U.S. most folks don't check their pressure nearly often enough. Tire pressure recommendations are made for reasons of safety, performance, and BRAKING. Keep in mind that your braking is also affected by the tire pressure. Nitrogen - to the question about using Nitrogen, it depends on where you live and the time of year, and your tolerance for cost. It's fairly expensive to have your tires Nitrogen filled (at least it seems pricey to me). I have considered its benefits when fall comes and I know my pressures will be all over the place until spring, but I have a compressor in the garage and check and adjust them regularly. The benefit of N is that it is less volitile and does not expand and contract as much as 'air' does in our atmoshperic range. If adjusting your pressures is not very convinient for you it is something to consider. __________________ I think it is bad luck to be superstitious
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09-23-2011, 04:15 PM	#14
cooldude00 First Lieutenant 7 Rep 332 Posts Drives: x3 2.0d Join Date: Jan 2011 Location: uk iTrader: (0)	checked the tyres earlier after collecting the car and they were set at 2.5bar instead of the recommended 2.0.. this is for 225/60/17. __________________ it's here!!!
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09-23-2011, 05:28 PM	#15
ivanoski F25 X3 2.0 Diesel 1 Rep 48 Posts Drives: 2012 BMW x3 20d 8SpdAUTO BLACK Join Date: Sep 2011 Location: Tegucigalpa, Honduras iTrader: (0)	Cant the Idrive tell you the tirepressure? i cant find the menu option for it...
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