# Sport Package Air Pressure



## drmwvr (Feb 21, 2003)

I am having a hard time figuring out the correct air pressure for my tires. As you can see in the picture below, the label BMW placed on my car does not recognize the fact that my car came with 225/45R17 on ALL four corners. Right now I am running 30 PSI in the front tires and 35 PSI in the rears. However, the rear pressure is based the chart showing 245/40R17s for the rear tires. Are the air pressures I am running correct?

EDIT: I have the Z rated tires if that matters.

Thanks!


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## tgravo2 (Dec 7, 2002)

I have the same setup as you, I always do 35/42 :dunno:


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## Mr. The Edge (Dec 19, 2001)

tgravo2 said:


> I have the same setup as you, I always do 35/42 :dunno:


42 is way high. that's only for when your car is full of people and stuff


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## tgravo2 (Dec 7, 2002)

atyclb said:


> 42 is way high. that's only for when your car is full of people and stuff


:dunno: 
:eeps:


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## ff (Dec 19, 2001)

30 seems pretty low. The handling precision and quickness will improve greatly if you increase the fronts a little. I run 35 in the front (P225's) and 37 in the rear. Feels pretty good to me.


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## Artslinger (Sep 2, 2002)

My tire pressures 34F/34R.


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## The Pawnbroker (Sep 7, 2003)

I know this sounds a little over the top (face it, that's probably why we're here), but I always take whatever vehicle I get to a scale (truck stop, roadside scale, landscape supply house (weighing mulch etc.) and weigh the front and rear axles. You can then contact the tire manufacturer through their web site or 800 number and get recommended pressures at various axle weights. Call your local RV sales center and ask them where there is a scale in your area. Make sure to find a place that can weigh the axles individually. I have gotten 80K plus out of Michelins using this method.

Dave.


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## bmw325 (Dec 19, 2001)

The Pawnbroker said:


> I know this sounds a little over the top (face it, that's probably why we're here), but I always take whatever vehicle I get to a scale (truck stop, roadside scale, landscape supply house (weighing mulch etc.) and weigh the front and rear axles. You can then contact the tire manufacturer through their web site or 800 number and get recommended pressures at various axle weights. Call your local RV sales center and ask them where there is a scale in your area. Make sure to find a place that can weigh the axles individually. I have gotten 80K plus out of Michelins using this method.
> 
> Dave.


That is a little over the top-- but a cool idea! Thanks.


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## mppaz (Aug 7, 2003)

Look in the owners manual. The manual for my 325i listed the recommended pressure for the sport package where as the decal did not.


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## drmwvr (Feb 21, 2003)

mppaz said:


> Look in the owners manual. The manual for my 325i listed the recommended pressure for the sport package where as the decal did not.


Already did that 

It refers me back to the sticker on the door...


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## mppaz (Aug 7, 2003)

drmwvr said:


> Already did that
> 
> It refers me back to the sticker on the door...


Weird. I know for a fact that my 2001 owners manual had it listed :dunno:


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## drmwvr (Feb 21, 2003)

mppaz said:


> Weird. I know for a fact that my 2001 owners manual had it listed :dunno:


Maybe it saved BMW 5 cents per manual to not put the air pressure info in it


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## mppaz (Aug 7, 2003)

drmwvr said:


> Maybe it saved BMW 5 cents per manual to not put the air pressure info in it


Here is a shot from the manual. Looks like 30/35 is correct.


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## Zaphod (May 23, 2002)

FWIW I run 34F/38r on mine and seem to like it. It was delivered with 30/30 and I can recall being concerned that if felt kind of sloppy. Fiddled with the pressure and it's been  since.


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## drmwvr (Feb 21, 2003)

mppaz said:


> Here is a shot from the manual. Looks like 30/35 is correct.


Your manual has the same problem as mine, it does not recognized the fact that the REAR tires on our cars come in the size 225/45R17. If you line up (in a vertical plane) the spot for the tire pressure and the rear tire shown in the drawing at the top of the page, you will notice a - which I guess means not applicable. You have to move down on the chart to the next tire size (245/40R17) to get tire pressure recomendations for the rear tires.

The 30/35 you noted is for two different sizes of tires.

Am I missing something?


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## Matthew330Ci (Sep 9, 2002)

my manual and my doorjamp sticker give contradicting information. unbelievable  :madrazz:

30/35 in the manual
32/38 on the doorjamb

 :madrazz:

I run 32/38 per the doorjamb.

 :madrazz:


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## mppaz (Aug 7, 2003)

drmwvr said:


> Your manual has the same problem as mine, it does not recognized the fact that the REAR tires on our cars come in the size 225/45R17. If you line up (in a vertical plane) the spot for the tire pressure and the rear tire shown in the drawing at the top of the page, you will notice a - which I guess means not applicable. You have to move down on the chart to the next tire size (245/40R17) to get tire pressure recomendations for the rear tires.
> 
> The 30/35 you noted is for two different sizes of tires.
> 
> Am I missing something?


The way I read this was the first entry (see attached) is for vehicles that have the same size tires all the way around. I believe this since there is no "lower" entry. If you look in that table it will out call the tire size for the SP(last one). If you read it that way it recommends 30/35.

Might be out of my mind :loco: but that's the way it interpreted it.


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## drmwvr (Feb 21, 2003)

mppaz said:


> The way I read this was the first entry (see attached) is for vehicles that have the same size tires all the way around. I believe this since there is no "lower" entry. If you look in that table it will out call the tire size for the SP(last one). If you read it that way it recommends 30/35.
> 
> Might be out of my mind :loco: but that's the way it interpreted it.


Maybe we are talking about different size tires; what size were to ones on your 325?


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## drmwvr (Feb 21, 2003)

Zaphod said:


> FWIW I run 34F/38r on mine and seem to like it. It was delivered with 30/30 and I can recall being concerned that if felt kind of sloppy. Fiddled with the pressure and it's been  since.


Thanks, I will try this combo tomorrow :thumbup:


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## Bob325 (Dec 16, 2002)

...can you imagine that an owners manual _*and*_ a door jam sticker can be so obtuse and confusing that the average BMW owner can't figure it out...
Hey...BMW NA...get it together..it can't be so difficult to transmit that extreme level of technical information to owners


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## jcatral14 (Aug 4, 2003)

Matthew330CiM said:


> ...I run 32/38 per the doorjamb...


Same here :thumbup: 
Unless the car is loaded up then its 35F/42R(I think)


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## 3C (Apr 6, 2002)

On my with sport pack -
F 30psi ; R35psi., but this summer I started doing F32psi and R37psi.



ps: Every 2 weeks the pressure goes down exactly with 1psi. (cold check Fcourse).


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## Plaz (Dec 19, 2001)

I run 40 all around on my car, and think it makes all handling much crisper, and provides a firmer ride, which I like.


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## MC (May 22, 2002)

I didn't follow the factory recommendation either. Somebody suggested 34 front and 35 rear. I am satisfied with the settings at this point. But 30 psi is too low. I would follow factory settings if you are satisfied with it, but try this settings.


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## drmwvr (Feb 21, 2003)

Bob325 said:


> ...can you imagine that an owners manual _*and*_ a door jam sticker can be so obtuse and confusing that the average BMW owner can't figure it out...


I would like to think that we are "above" average


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## mppaz (Aug 7, 2003)

drmwvr said:


> Your manual has the same problem as mine, it does not recognized the fact that the REAR tires on our cars come in the size 225/45R17. If you line up (in a vertical plane) the spot for the tire pressure and the rear tire shown in the drawing at the top of the page, you will notice a - which I guess means not applicable. You have to move down on the chart to the next tire size (245/40R17) to get tire pressure recomendations for the rear tires.
> 
> The 30/35 you noted is for two different sizes of tires.
> 
> Am I missing something?


OK. Not to make this the longest thread on tire pressure but I think I know the difference. My car (2001 325i SP) came with the 225/45 W rated tires. Using this information the manual and the doorjamb align at a recommended pressure of 30/35 (for normal conditions). I would believe that they would recommend the same pressure for Z rated tires as well. All that said this is only a recommendation. You will find tons of information in this web site as to what people run and why. Try a search like "tire pressure understeer". Basically most people will increase the pressures to firm up the ride and tune out some of the understeer. I also found 30 on the front to be a little too mushy. If memory serves me I think I ended up running around 35/38.


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## JB330Ci (Feb 17, 2002)

:bigpimp: 
I am surprised that no one suggested 35F/30R (or any front pressure > rear pressure) to correct the understeering of the stagging tire sizes yet. :bigpimp:


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## drmwvr (Feb 21, 2003)

JB330Ci said:


> :bigpimp:
> I am surprised that no one suggested 35F/30R (or any front pressure > rear pressure) to correct the understeering of the stagging tire sizes yet. :bigpimp:


If you meant staggered, the sport package tires on the 325 (at least MY2003) are all the same size. :dunno:


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## edsmax (Jul 28, 2003)

*Just go with what BMW says....*



drmwvr said:


> I am having a hard time figuring out the correct air pressure for my tires. As you can see in the picture below, the label BMW placed on my car does not recognize the fact that my car came with 225/45R17 on ALL four corners. Right now I am running 30 PSI in the front tires and 35 PSI in the rears. However, the rear pressure is based the chart showing 245/40R17s for the rear tires. Are the air pressures I am running correct?
> 
> EDIT: I have the Z rated tires if that matters.
> 
> Thanks!


I always run 30 in front and 35 in rear....its alwasy just myself in the car, sometimes my wife in the passenger seat. The car handles great.

Ed


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## sshuit (Apr 15, 2002)

30F / 35R gives me a bit of understeer .

I am now running 35F / 35R for daily driving.

At autoX I'm running 42F / 38R to get some nice controllable power oversteer.

(note all results with full stiff UUC Swaybarbarians)



edsmax said:


> I always run 30 in front and 35 in rear....its alwasy just myself in the car, sometimes my wife in the passenger seat. The car handles great.
> 
> Ed


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## PABS (Apr 3, 2003)

The tire rack told me 36 all around w/sp package.


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## brewthunda (May 15, 2003)

drmwvr said:


> I am having a hard time figuring out the correct air pressure for my tires. As you can see in the picture below, the label BMW placed on my car does not recognize the fact that my car came with 225/45R17 on ALL four corners. Right now I am running 30 PSI in the front tires and 35 PSI in the rears. However, the rear pressure is based the chart showing 245/40R17s for the rear tires. Are the air pressures I am running correct?
> 
> EDIT: I have the Z rated tires if that matters.
> 
> Thanks!


Go look at your tires again. They probably say 225/45/ZR17 91W or something like that.

The way I read that chart is that your tires fall into the description of "225/45 R 17 91W" . . and thus your tires are represented by a little triangle. Fill it up to 30 psi front, 35 psi rear.


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## Artslinger (Sep 2, 2002)

There probably is no right tire pressure... do you want a firm or softer ride, do want oversteer or understeer. Most important is to not under inflate or over inflate the tires.


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## EddieB (Jun 5, 2003)

edsmax said:


> I always run 30 in front and 35 in rear....its alwasy just myself in the car, sometimes my wife in the passenger seat. The car handles great.
> 
> Ed


That's about what I do, 32F and 37R. Same pax load, mostly myself. Sometimes dog or wife.


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## drmwvr (Feb 21, 2003)

brewthunda said:


> Go look at your tires again. They probably say 225/45/ZR17 91W or something like that.
> 
> The way I read that chart is that your tires fall into the description of "225/45 R 17 91W" . . and thus your tires are represented by a little triangle. Fill it up to 30 psi front, 35 psi rear.


Interesting observation...so why does it have to be so complicated to figure out? :dunno:


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## 3seriesbimmer (Jun 20, 2002)

ff said:


> 30 seems pretty low. The handling precision and quickness will improve greatly if you increase the fronts a little. I run 35 in the front (P225's) and 37 in the rear. Feels pretty good to me.


I as well..... it's ALL personal preference


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## dynosor (Jul 15, 2003)

*There is more than one way to tune a car's handling with tire pressure*

30 Psi is too soft for the rear suspension. My 330i SP bobs and wobbles all over the place on the tire sidewalll with anything less than 35 Psi in the rear tires. 34 / 37.5 Psi F/R works well for me.

There is more than one way to tune a car's handling with tire pressure:
http://mgaguru.com/mgtech/tires/sp104.htm


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## kyleschultz (May 29, 2003)

I have '03 330i SP. 225/45 ZR17 on front and 245/40 ZR17 on the rear. After much research on this board, I'm running 39 psi all the way around. Car handles wonderfully.

On first blush, that seems like pretty high pressures but check your door jamb. Mine lists max ranges (depending upon load) of 32-39# for the front and 38-46# for the rear. Geneerally I only have 1 passenger with me but I gig the front pressures up to the max in order to offset some of the understeer that the staggered tire setup induces. There is tons of info on this subject in the archives.


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