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Tire Pressure


vmodi
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The R50 manual says that the tire pressure should be 26psi but it seems to too low. At 26psi it looks as if the tires are almost flat. I am running stock tires. What do people usually inflate to?

 

Thanks.

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Signed in to give you information about calculation of tire-pressure.

Found this topic when googling for tire-pressure.

 

I live in Holland and in 2007 got hold of the system the tire manufacturers in Europe use to determine the advice-pressure for radial tires, and worked it out.

Learned myself Excell to make spreadsheets for it. In 2009 I discovered that this system, as I thought was was worldwide, was diferent in Europe and America.

The basic Equation is the same, but the power used for calulating weight for a sertain pressure was diferent up to 2000, from 2005 for normal car tires it is upgraded in America to the European one. Found an article about a new suggestion of calculating, in wich the indentation of the tire stays the same at a lower load then the maximum, and comparison with the since 1928 used universal power Equation,and its diferent powers used.

I am now busy making my own system based on that article wich comes to higher pressures, so always is saver then the power-equation ,even of Europe, wich is reasonably save for normal and reinforced car tires.

 

collect the asked data in the spreadsheet in the next map, and fill in . Then you get advice for normal use ( 3 persons an a little load, given in Europe, up to 2000, but not in America) , for Heavy load ( using the Gross axle weight ratings, and now called normal for 4 persons and load) and for vacation load( over- or uneven loaded rear axle, mostly when towing a trailer), and those 3 for up to 160 km/h and up to maximum speed of car).

recalculating tire pressure

 

The article you can find here

and is in English.

From these links you can navigate my complete public map of skydrive wich belongs to my hotmail adres with the same user name as in this forum, so combine it and you can mail me for questions, or give me a personal message here

 

At last, to my opinion the changes made in the system between 2000 and 2005, are not coincidentialy parallel to the Ford/Firestone affaire .

 

Greatings from Holland

Peter

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I run my tires at ~34 psi. I have 31x10.50 on 10" wide wheels. This seems real good for everyday driving. Of course I lower it when I go 'the road less traveled' unless it's sand, in wich I only lower the rear pressure (learned this was the best setup for ME, as most people lower all tires).

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you could always experiment with a piece of chalk. Draw a line across the tire, drive for a little bit and see where the chalk wears off first. If it wears off evenly, you have good pressure, If it wears off in the middle first, decrease your pressure, if it wears off on the outsides first, increase your pressure.

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manufacturer's setting is always the way to go.

 

really, the only times you want to overinflate is if you're carrying a heavier load, which would obviously displace the tire more. there's few instances to underinflate the tires for street applications (off-road is whole other animal).

 

if you're running regular, compressed air, it'd be a little more proper to run slightly higher pressures as the cold air will drop the pressure in the tires. regular, compressed air fluctuates quite a bit as it'll vary anywhere from 2-5psi in either direction when the tires are hot or it's hot outside, or when the tires are in colder climates.

 

if you have access to it, i'd recommend inflating your tires with Nitrogen (the Costco tire shops run strictly on Nitrogen). Nitrogen is a dry gas that doesn't fluctuate with temperature changes the way regular, compressed air does. however, for most of the hardcore off-roaders, Nitrogen isn't a possibility as they'll need to inflate and deflate their tires on a regular basis.

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  • 2 weeks later...

Sorry for the late response, was on travel for a week.

 

I just bumped by tire pressure to 30 in all tires today. I am running the stock factory size tires and rims.

 

Thanks for all the suggestions!

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the WD21s with the 31" tires are a little different. they required an LRC/6-ply tire, and most of those tires maintained its shape quite a bit better regardless of the air pressure, so the WD21s have a bit of an advantage there.

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I ran stock sized tires on my truck for a couple years @28psi and ended up with some noticeable cupping, so the last while I ran them I did so at about 32psi and they seemed much better (plus fuel mileage improved noticeably).

 

Now I run 31" duratracs on steelies and I've got them at 32psi and am considering putting a bit more in.

 

Way back when I was taught that regardless of what the tire said you should run what the vehicle spec was in the tires. That however doesn't take into account different sized tires, especially if they're noticeably larger or smaller than stock. And if you're getting uneven wear (do a chalk test) in terms of cupping or bulging, then your tire pressure is wrong no matter what the door placard says.

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working at dealerships and what not, we set all half-tons, SUVs and minivans to 35psi

it's a pretty safe pressure to run

I never ran anything less than 32psi on-road...

 

Hunh....That's 34% higher than the 26 recommended for mine. Not saying 32 would cause a problem necessarily....But recommended PSI exists for a reason and isn't random. Does Nissan not know what they are doing when it comes to the pressure they area specifying for the vehicles they build? Or is this another reason why people abhor dealerships? ....just saying...

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My sticker says 30 psi on all tires.

mine too.

(2002 4WD SE)

And I am sure manufacturer knows better.

Quite often when I get my truck to the mechanics shop they set pressure to 38 or 40psi.

I guess at this pressure the tire life is just 50% sop they can sell twice more tires :)

Edited by peterzulu
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Hunh....That's 34% higher than the 26 recommended for mine. Not saying 32 would cause a problem necessarily....But recommended PSI exists for a reason and isn't random. Does Nissan not know what they are doing when it comes to the pressure they area specifying for the vehicles they build? Or is this another reason why people abhor dealerships? ....just saying...

 

there's an old school motto of, "35 saves lives." my tire shop manager says that all the time. much of it came from the whole Bridgestone/Firestone recall years ago. the 26psi recommendation was supposed to have been changed though. 30 is the best pressure to run for max comfort. that's the main focus that Nissan had in mind with that recommendation. setting it a couple pounds higher gives you better handling and a firmer ride. i typically run mine at 31-32psi and have been very happy with that.

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working at dealerships and what not, we set all half-tons, SUVs and minivans to 35psi

it's a pretty safe pressure to run

I never ran anything less than 32psi on-road...

 

Same here at Les Schwab (I hate that place, by the way).

 

We've never had a single complaint of uneven wear on any vehicle the entire time I worked there, we set everything to 35 unless the customer asks otherwise. I noticed poor tread wear only on tires inflated below 30 PSI and above 40 PSI, but never within 32-38.

 

26 PSI is stupid for the street unless it's a dedicated MT, where that's too much pressure. I'd prefer not to drive an oafing whale around town that accelerates, stops, and corners like ass with a noticeable drop in fuel economy. No thank you! Like I said before, 35 PSI and perfect tread wear on my Pathfinder running 31" Michelin ATs.

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ive been running my 31x 10.5 x15" M/S at 32-35 on road and 15-20off road (no on board air) and ive noticed a little extra tread wear in the centre...i like the more resonsive feel with the stiffer tire but fear uneven wear!

Tye

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  • 9 years later...

I need to figure out what to do to mine. Running BFG All Terrain K02 on the stock 1998 Pathfinder Chilkoot rims.

 

Noticed the pressure looked uneven so I bought a pressure tester and they were allllll over the place! Bad wear on one tire. On the actual tire it says pressure not to exceed 50psi at 1895lbs or something. Put them all up to 40psi but that seems like way too much based on this thread. Will release them down to 35 each today. Any other suggestions?

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