What's the right tire pressure for my tires?

PopsnBurbles · 03-30-2011, 02:37 PM

Well, for starters, I got my (2010) 328 sedan last year. It's got the 17" run flat tires. I read the sticker on the driver's side door and it says 31-33(i forgot I'm pretty sure it's 32) psi (front) and 39 psi (rear). I referred to the car's owner manual and it says the same thing.

I checked my tire pressures (for all four tires) and the front tires were 26psi each and the rear ones were 29 psi. That's a HUGE difference compared to the "suggested" tire pressures. Despite that difference, the tire sensors still doesn't warn me of having low/weak tire pressures.

I would like to increase the tire pressures up to the suggested but I'm scared that it might get too stiff and be more prone to bursting/breaking (even more so on run flats because of the thick tires).

BTW, I'm new to the forum...sorry if this has been asked before.

SeanS54 · 03-30-2011, 02:39 PM

run what the manual/door jam sticker says... make sure it's cold PSI... don't worry about it bursting at those psi, it won't happen... you can run as high as 40psi cold all around without any problems

PopsnBurbles · 03-30-2011, 03:56 PM

k thanks. yes, i tested it cold. I mean, if I had the tests while the tires were recently used/hot, wouldn't the psi shoot up by about +4 on average?
Well, I'm not very good with cars that's why I went here.

Anyways, more questions. If I increased the tire pressure to the suggested, would the ride feel get stiffer? Again, thanks.

SeanS54 · 03-30-2011, 05:16 PM

if there's not enough air the ride would be harsh.. if there's too much the ride would be harsh.. just set it to factory specs or run 35psi all around...

PopsnBurbles · 03-30-2011, 05:40 PM

k ty lastly.
Just curious, will the MPG be better or worse or just about the same (if I ran with the suggested tire pressures?) Right now, I average 23MPG~24MPG city and about 27MPG-28MPG freeway/highway.

Of course, I get lower than 15 in severe traffic and 14 when I drive crazy.

dryicerx · 03-30-2011, 06:25 PM

Run flats behave quite differently to tire pressure that normal (where the ride quality smooths out when it's over a certain limit).

Make sure you are looking at the correct sticker on the door jam (on my 2011 335is, there were two stickers, a yellow one and a white one, use the yellow sticker... I actually totally missed it for a while)... (42 and 49 PSI if I remember correctly). RFT tires require much higher pressure than regular tires, this is completely normal and makes the ride great when it's at correct pressure.

03-30-2011, 02:37 PM	#1
PopsnBurbles Captain 193 Rep 894 Posts Drives: 135is :) 192/586 Join Date: Mar 2011 Location: LA, CA iTrader: (4) Garage List 2003 Lotus Esprit V8 [0.00] 2013 BMW 135is Coup ... [10.00]	What's the right tire pressure for my tires? Well, for starters, I got my (2010) 328 sedan last year. It's got the 17" run flat tires. I read the sticker on the driver's side door and it says 31-33(i forgot I'm pretty sure it's 32) psi (front) and 39 psi (rear). I referred to the car's owner manual and it says the same thing. I checked my tire pressures (for all four tires) and the front tires were 26psi each and the rear ones were 29 psi. That's a HUGE difference compared to the "suggested" tire pressures. Despite that difference, the tire sensors still doesn't warn me of having low/weak tire pressures. I would like to increase the tire pressures up to the suggested but I'm scared that it might get too stiff and be more prone to bursting/breaking (even more so on run flats because of the thick tires). BTW, I'm new to the forum...sorry if this has been asked before.
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03-30-2011, 02:39 PM	#2
SeanS54 Captain 174 Rep 860 Posts Drives: M4 ZCP, E46 M3, '21 Tacoma Join Date: Jan 2011 Location: Bay Area, CA iTrader: (20)	run what the manual/door jam sticker says... make sure it's cold PSI... don't worry about it bursting at those psi, it won't happen... you can run as high as 40psi cold all around without any problems __________________ https://www.youtube.com/user/SeanS54/videos
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03-30-2011, 03:56 PM	#3
PopsnBurbles Captain 193 Rep 894 Posts Drives: 135is :) 192/586 Join Date: Mar 2011 Location: LA, CA iTrader: (4) Garage List 2003 Lotus Esprit V8 [0.00] 2013 BMW 135is Coup ... [10.00]	k thanks. yes, i tested it cold. I mean, if I had the tests while the tires were recently used/hot, wouldn't the psi shoot up by about +4 on average? Well, I'm not very good with cars that's why I went here. Anyways, more questions. If I increased the tire pressure to the suggested, would the ride feel get stiffer? Again, thanks.
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03-30-2011, 05:16 PM	#4
SeanS54 Captain 174 Rep 860 Posts Drives: M4 ZCP, E46 M3, '21 Tacoma Join Date: Jan 2011 Location: Bay Area, CA iTrader: (20)	if there's not enough air the ride would be harsh.. if there's too much the ride would be harsh.. just set it to factory specs or run 35psi all around... __________________ https://www.youtube.com/user/SeanS54/videos
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03-30-2011, 05:40 PM	#5
PopsnBurbles Captain 193 Rep 894 Posts Drives: 135is :) 192/586 Join Date: Mar 2011 Location: LA, CA iTrader: (4) Garage List 2003 Lotus Esprit V8 [0.00] 2013 BMW 135is Coup ... [10.00]	k ty lastly. Just curious, will the MPG be better or worse or just about the same (if I ran with the suggested tire pressures?) Right now, I average 23MPG~24MPG city and about 27MPG-28MPG freeway/highway. Of course, I get lower than 15 in severe traffic and 14 when I drive crazy.
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03-30-2011, 06:25 PM	#6
dryicerx First Lieutenant 25 Rep 379 Posts Drives: 335is Join Date: Jun 2010 Location: Austin, TX iTrader: (1)	Run flats behave quite differently to tire pressure that normal (where the ride quality smooths out when it's over a certain limit). Make sure you are looking at the correct sticker on the door jam (on my 2011 335is, there were two stickers, a yellow one and a white one, use the yellow sticker... I actually totally missed it for a while)... (42 and 49 PSI if I remember correctly). RFT tires require much higher pressure than regular tires, this is completely normal and makes the ride great when it's at correct pressure.
	Appreciate 0 Quote