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BMW 3-Series (E90 E92) Forum
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What Tire Pressure Are You Guys Running???
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03-07-2014, 12:50 PM | #1 |
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What Tire Pressure Are You Guys Running???
I have the OEM Bridgestone Potenza RE A050 RFT tires. I am running 36 PSI at all 4 corners. Many seem to run 38-40 psi for rears but I find the ride to be pretty harsh due to the RFT tires being so stiff. I have sports suspension also.
I could see running 35 f and 40 r if I got new tires that weren't RFT. Maybe Michelin PSS. Anyone else find it hard to run what factory recommends for pressures due to stiffness of the RFT tires??????? I am probably sacrificing some gas mileage also with my tire pressures. I am getting 28,6 mpg now. |
03-07-2014, 01:07 PM | #2 |
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I usually run 5 psi below the max sidewall recommendation. Car/ truck/ Suv....
While its firmer I feel better in corners and get better mileage out of my tires. Creature of habit. Now motorcycles, I run what the manufacturer recommends. |
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03-07-2014, 02:11 PM | #3 |
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I run a couple psi below what the book shows for sport package speeds over 100mph. In other works, I'm running 39 up front and 46 in the back. I would think especially in the rears at 36 on sports you would be under inflated and having uneven wear. Aside from mpg you're giving up some performance, maybe some tire life. I didn't notice a difference in ride quality on rfts between 38 and 46.
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03-07-2014, 04:49 PM | #4 |
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Think I will go with 36f and 40r now...I didn't think the tire grip would be affected much by going lower pressure but maybe it will...hopefully I can get up to 30mpg.
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03-07-2014, 05:16 PM | #5 |
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I don't know that grip is the right word. Its more related to the sidewall stiffness, higher pressure can help stiffen up the sidewall, better cornering stability. Don't know how much that really affects rfts but some tires with softer sidewalls can see a big difference with just a couple psi
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03-07-2014, 09:19 PM | #6 | |
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03-08-2014, 12:14 AM | #8 |
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Just picked up a 2010 CPO non-sport that has new Bridgestone Turanza el42 rft's. Right now i'm running the factory 33 front and 41 rear but don't find the ride to be too harsh. Its firm but good for me. Getting 36-40mpg with those air pressures and driving near the speed limit.
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03-08-2014, 09:40 AM | #9 |
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My OEM sport package Bridgestones are listed to have 35 PSI front, 42 PSI rear. I find them to be softer if the air pressure is increased by 2 PSI all around!
The increased pressure in the fronts makes a big difference in steering making it a bit lighter, while the rears have more to do with the ride and it seems the extra air keeps them off the RFT sidewalls. It doesn't help the "bounciness" I feel going over speed bumps etc. though. The tires are still good after almost 40,000 miles with maybe a couple of thousand more and have worn very evenly. |
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03-08-2014, 01:27 PM | #11 |
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I have a square setup. I have been running 36 psi all around since my first HPDE instructor suggested it might make it a little more neutral (i.e., less understeer). Seems to work fine for me. I put a couple more psi for long road trips. Tire wear has been fine.
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03-13-2014, 02:29 PM | #12 |
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35/41 with PSS. America's Tires' recommendation.
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03-17-2014, 03:30 PM | #15 | |
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I've always been confused about the higher recommnded pressures ( on the door sill sticker) for high speed driving. I've ran high pressure a long time ago and the tire wore out prematurely along center of tread. Can a tire expert chime in here please? |
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03-17-2014, 05:58 PM | #16 | |
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03-17-2014, 07:16 PM | #17 |
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I usually do 35 front, 41 rear... Also as I've never had any experience with RFT, how often do you have to top off the tires? I don't track my tire pressure as much as I should, but it seems to lose more pressure than non-RFTs? I noticed each wheel loses about 1.5 PSI a month so I keep it at high normal just so it stays within normal range instead of being underinflated.
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03-17-2014, 10:35 PM | #19 |
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Hmm... If it's one wheel then I can rule either that or a slow leak in the tire out, but I doubt that all 4 tires will go at the same time. Thanks though.
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03-18-2014, 12:04 AM | #20 |
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Yeah I'd say that's pretty unlikely. I don't think 1.5 psi per month sounds out of line, especially in the winter.
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03-18-2014, 01:32 AM | #21 |
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Well, I know that 1 PSI is kinda average, but I'm just averaging it out, but in reality it seems to be more than that; the last time I filled the tires was around January and it lost about 5 PSI, and just as a control, I always overfill it a bit at the gas station and empty it out to spec when I'm parked so there's no heat variation from driving... Compared to my last cars which have held pressure no problem with perhaps 1-2 PSI for the same timeframe. Maybe I'll invest in nitro, perhaps?
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03-19-2014, 05:46 PM | #22 |
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Nitrogen provides little benefit to your tires and you're just better off getting free compressed air.
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