tyre pressures on road

[WORTHOS6]

hi team
just purchased some bridgestones & feel like running at to low a pressure
dealer had them at 35 psi but i still feel gripping up to much (not standing up)

had some aPerellies at 36 psi no problems.
i have afreind with a Cruiser that runs ate 50 psi

any advise would be great as these tyres are costly & can feel money being left on the road

cheers

[Dhuck]

Welcome to the forum mate. What brand and type of tyre are they (mt, at etc)

[Woof]

No idea mate but try this site: http://www.bridgestone.com.au/tyres/passenger/care/pressure.aspx

[WORTHOS6]

285/70/17 AT's mate

[Dhuck]

What brand mate as different manufacturers have different pressures.

[ecrusty]

I think most 4x4 tyres are supposed to be run at 40-45 psi for normal tarmac driving. I could be wrong and please tell me if I am, but I have run under this assumption for over 20 years with no ill effects. At the moment I run my 65 series ProComps at about 38-40 for a bit of comfort and have not noticed any abnormal wear.

[WORTHOS6]

thanks ecrusty

i am running them around 40psi a little better but still not happy will try them at 45 mate

[MQ MAD]

I run 40 PSI in all the 4bys,and 50PSI loaded

[NissanGQ4.2]

Run 40psi in my BFG a/t

[Finly Owner]

Some can take 60 psi with no heat probs or any distorion probs. Check the rating on sidewall.

[Dhuck]

Some can take 60 psi with no heat probs or any distorion probs. Check the rating on sidewall.

That is right on the nose Tim. I have unfortunately got Goodyear Muds and run them at they're max of 35 on road (noisy as all f@#k). BFG AT's when I was in the tyre game we ran at 45 on road. I had a customer who had BFG MT's that lasted 110,000. Unbelievable but true. He ran them at 45 rear with load and 40 front (he had 6 wheels rotated every 10,00 km's). But generally run what the sidewall say's in a wagon. In a ute or shorty run 5 pound less than what sidewall say's if unloaded. Just a hint BFG is now made by Michelin (has been since about 2001) and a tyre that runs a max of 50 will go well above 60. This is tested and proved. Have a look at some of the Asian vehicles that run BFG/Michelin. They carry 4t on a 2t truck. As for heat, more is generated at lower pressures than high this causing delamination and separations. This is why race cars (V8 Supercars (Holden of course)) start with lower pressures than required. As they heat up the gain pressure.

Unfortunately this is only a guide. It all comes down to the terrain and driving style/load etc. It will come down to what you find as the correct pressure for you.

Remember over pressure wears the middle of the tyre and under pressure wears the shoulder. All manufacturers are different. Nobody drives the same. Once tyres are worn they will continue to wear that way until they are dead (unless you have a wheel alignment issue).

Worthos6 I recommend you start off at 45 and work from there.

[WORTHOS6]

thanks guys great info

[Maxhead]

I used run my D693's at 38.
Just experiment different pressures and apply the 4 or 6 psi rule.

Inflation and the 4 psi rule

Tyre pressures vary for every vehicle and caravan depending on weight loads, size etc. An easy do-it-yourself method for checking you have the correct tyre pressure for your vehicle and caravan is known as the "4 psi rule".

Firstly you need to inflate all tyres to the pressure recommended by the manufacturer, for a "cold tyre" reading and then tow your caravan for say a distance of 100 klm on bitumen.

Upon stopping, immediately recheck your tyre pressure while the tyre is still warm.

If your tyre pressure reading is greater than 4 psi from the "cold tyre" reading you took at the beginning of your trip, then the tyres are getting too hot and your starting tyre pressure was too low. Under inflated tyres wear unevenly and lead to increased fuel consumption. They can also impair the handling of the vehicle in the areas of braking and handling.

If the tyre pressure reading is less than 4 psi from the "cold tyre" reading you took at the beginning of your trip, then your starting tyre pressure was too high. You will need to run the test again (once the tyre has completely cooled) with less pressure until you find the right balance.

It is acceptable for larger 4WD's to have a 6 psi difference between the pressure at the commencement of the trip, and after 100 klm of travel.

Remember to use the same accurate gauge for all pressure readings and always carry a gauge with you when possible.

[Dhuck]

I used run my D693's at 38.
Just experiment different pressures and apply the 4 or 6 psi rule.

Inflation and the 4 psi rule

Tyre pressures vary for every vehicle and caravan depending on weight loads, size etc. An easy do-it-yourself method for checking you have the correct tyre pressure for your vehicle and caravan is known as the "4 psi rule".

Firstly you need to inflate all tyres to the pressure recommended by the manufacturer, for a "cold tyre" reading and then tow your caravan for say a distance of 100 klm on bitumen.

Upon stopping, immediately recheck your tyre pressure while the tyre is still warm.

If your tyre pressure reading is greater than 4 psi from the "cold tyre" reading you took at the beginning of your trip, then the tyres are getting too hot and your starting tyre pressure was too low. Under inflated tyres wear unevenly and lead to increased fuel consumption. They can also impair the handling of the vehicle in the areas of braking and handling.

If the tyre pressure reading is less than 4 psi from the "cold tyre" reading you took at the beginning of your trip, then your starting tyre pressure was too high. You will need to run the test again (once the tyre has completely cooled) with less pressure until you find the right balance.

It is acceptable for larger 4WD's to have a 6 psi difference between the pressure at the commencement of the trip, and after 100 klm of travel.

Remember to use the same accurate gauge for all pressure readings and always carry a gauge with you when possible.

Don't want to be a contradicting bastard but that rule was fine 20 years ago. Same as the tyre placard on cars. Tyre placards recommend pressures for comfort. These days tyres need an extra 10lb (approx) due to the construction of the tyre. Every tyre I have seen since the late 90's requires to be run at 40 to 44 lb (4x4 and passenger) apart from MT's and similar which have a max of about 35lb. I would advise any owner to run a wagon at mid 40's, swb and utes at low 40's.

What ppl need to remember, tyres were constructed of rubber and canvas then rubber, canvas and steel. Now there are very few tyres with canvas (now usually only in the side wall) . To push the tread out enough in modern tyres we need to run a higher pressure due to the amount of steel belts (usually 3 or 4 belts).

Sorry Kris spent to many years in the tyre game.

[Maxhead]

Don't want to be a contradicting bastard but that rule was fine 20 years ago. Same as the tyre placard on cars. Tyre placards recommend pressures for comfort. These days tyres need an extra 10lb (approx) due to the construction of the tyre. Every tyre I have seen since the late 90's requires to be run at 40 to 44 lb (4x4 and passenger) apart from MT's and similar which have a max of about 35lb. I would advise any owner to run a wagon at mid 40's, swb and utes at low 40's.

What ppl need to remember, tyres were constructed of rubber and canvas then rubber, canvas and steel. Now there are very few tyres with canvas (now usually only in the side wall) . To push the tread out enough in modern tyres we need to run a higher pressure due to the amount of steel belts (usually 3 or 4 belts).

Sorry Kris spent to many years in the tyre game.

All good mate, just what the tyre place tells me to use.

Also, just noticed the bridgestone link Doggy posted above sais not to inflate tyres above 40psi if travelling at high speed

[Dhuck]

Unfortunately they want us to spend money on tyres. All they see is $$$$$$$$$ for every tyre we buy.

[Finly Owner]

Actually Chris, Defence driving course always contradict Manufacturers and tyre dealers and say add more if travelling long distance to avoid tyre damage. It's all very confusing, I do trust what Dhuck says as it has been taught to me like he says, I've had no probs, and have seen lots of people who disagree with me, have more trouble with tyres than I do.

[Maxhead]

Actually Chris, Defence driving course always contradict Manufacturers and tyre dealers and say add more if travelling long distance to avoid tyre damage. It's all very confusing, I do trust what Dhuck says as it has been taught to me like he says, I've had no probs, and have seen lots of people who disagree with me, have more trouble with tyres than I do.

Yeah, definitely not doubting the knowledge and it wouldn't surprise me one bit that tyre manufactures trying to make more $$$ (as usual, and if tyres don't cost enough already).
Its good to have blokes on here with the knowledge to put things straight.

I even did a quick google and even NRMA is trying to promote the 4psi rule....go figure

Anyways boys, very good information:cheers:

[Bigrig]

G'day mate - welcome aboard. (sorry for the copy and paste introduction, but been away for over a week and a lot of catching up to do!!! LOL). As you've no doubt noticed, heaps of useful information, great people and a good laugh to be had on the forum so make the most of it and get amongst the conversations. Don't forget to throw a few happy snaps of the rig up in the members ride section - we never get bored of looking at them!!!

I have always run my tyres (irrespective of brand) at between 36-38 psi for highway driving - you can increase them to above that for fuel economy reasons etc, but the I find the ride becomes too rigid. In that range, I tend to get the best wear - not too much belly to wear out the centres on highway, not too soft so that the corners scrub out ... all the best with sorting it.

[patch697]

Welcome on board & I hope you enjoy the forum.

[WORTHOS6]

hi team
i must admit this is a great forum
heaps of knowlage out there
thanks heaps for all the feed back
startin to feel part of the fam

[Finly Owner]

That's what we like to hear

[NUGGET]

Bugger now Im getting confused with the tyre pressures, na not really I had two B/Stones Duellers fitted on the back and the fitted assured me that 36 was the best for around town, I know if i put more in them when the wagon is empty its like ridding a bull, Im just waiting for the 8 second bell to ring so I can get out. But I pump them up to 40 when its loaded up and we are off on the black trail.

[boggy2006]

I had about 35psi in my Duellers, but they were still bulging a bit so have gone up to 40psi this week. Will see if that improves economy. Seems to ride ok still.

[molongmick]

I had my stock standard tyres up to 48psi and got an extra 2L/100km, standard setting was 37psi.

[Finly Owner]

I had my stock standard tyres up to 48psi and got an extra 2L/100km, standard setting was 37psi.
This is true in many vehicles.

[jace75]

so do we just go by look and feel then ? is the 4 PSI rule still the norm? and what was the 6PSI allowed for 4x4?

[DX grunt]

I run mine at 45psi

[Sir Roofy]

i run my bighorns at 40psi and was thinking of going back to 38psi as they seem to hard just running about town

roofy

[the evil twin]

I run mine at manufactureres specs initially and adjust accordingly... no maker is going to tell you pressures that chew thru his tyres deliberately.. he'll be out of business in a year.

You also cannot just compare tyre pressures... there will be anything up to 15 maybe 20 PSI difference between LT and Passenger tyres, ply's, rim width, suspension etc and so some people here will be quoting apples and others oranges... some will have utes with an ally tray that skitter everywhere at 38 PSI others will have Telstra cabs with a heap of gear that need 48 PSI

The sidewall presure is also meaningless as other than a max inflation figure which is the sole reason that it is there. Remember the bloke who made the LT tyre designed and constructed it to go on Light Trucks, thats any Truck/4WD/Vehicle single/dual wheel etc etc NOT Nissan Patrols in particular... sama sama Passenger constructs.

Given a specific tyre manufacturer, type, size, rims and identical vehicle...Some people will run at say 36 PSI looking for comfort and another will choose say 44 PSI in search of that last bit of fuel economy they can get and bugger the teeth rattle.

[DX grunt]

another will choose say 44 PSI in search of that last bit of fuel economy they can get and bugger the teeth rattle.

Diesel at my local roadhouse is $1.43 cpl and ULP (normal) is selling for $1.46 cpl, as we speak.

I don't have much choice and I know a great dentist! lol, sort of

[the evil twin]

Diesel at my local roadhouse is $1.43 cpl and ULP (normal) is selling for $1.46 cpl, as we speak.

I don't have much choice and I know a great dentist! lol, sort of

Fair enough too Roscoe... and yet another advantage of cheesecutters... less rolling resistance thus better fuel economy

[Dhuck]

I run mine at manufactureres specs initially and adjust accordingly... no maker is going to tell you pressures that chew thru his tyres deliberately.. he'll be out of business in a year.

You also cannot just compare tyre pressures... there will be anything up to 15 maybe 20 PSI difference between LT and Passenger tyres, ply's, rim width, suspension etc and so some people here will be quoting apples and others oranges... some will have utes with an ally tray that skitter everywhere at 38 PSI others will have Telstra cabs with a heap of gear that need 48 PSI

The sidewall presure is also meaningless as other than a max inflation figure which is the sole reason that it is there. Remember the bloke who made the LT tyre designed and constructed it to go on Light Trucks, thats any Truck/4WD/Vehicle single/dual wheel etc etc NOT Nissan Patrols in particular... sama sama Passenger constructs.

Given a specific tyre manufacturer, type, size, rims and identical vehicle...Some people will run at say 36 PSI looking for comfort and another will choose say 44 PSI in search of that last bit of fuel economy they can get and bugger the teeth rattle.

Isn't the sidewall pressure the pressure that the maker is telling you.

Sorry just a little contradicting. The sidewall pressure is the manufacturers specifications. It gives you the load and pressure recommended by the manufacturer to carry that load. We can delve deeper into this and look into load and speed rating.

[Finly Owner]

Ok people here is a rule you cannot ignore for tyres no matter size, wall thickness, surface use, vehicle type:

If your side wall is bulging and you inflate only to reveal sidewall rubbing, you have been running it under inflated. You may even have to change you tyre type to remove this effect, to compensate for the weight being carried by them. Eg you may have to go up to 8ply from 6ply.

[the evil twin]

Isn't the sidewall pressure the pressure that the maker is telling you.



No... Sorry but IMHO you are incorrect there, Cobber, because the manufacturer doesn't know what the tyre is going to be fitted too, Surf, Frontera, Rodeo, Navara, Patrol, Hummer, Dyna, Hino, Fuso...

From Hankook website- "In addition, the maximum inflation pressure for safe driving is marked on the tyre sidewall"
From Michelin website - "...on the tire side wall shows the max allowable inflation pressure."
From Cooper website- "Do not exceed the maximum pressure indicated on the tire sidewall."
From Kuhmo website - "Do not exceed the maximum inflation pressure labeled on the tire sidewall"
etc etc they are direct quotes from the Manuf (pls excuse some paraphrasing).

There are mobs (and my local Bob Jane is one of them) who told me and other family to ignore the pressure as it is just a manuf recommendation. IMHO grab your money and run do not walk to another supplier if any pimply faced d1ckhead tries to tell you that... or better still try a Warranty Claim.

However... I MUST add one disclaimer in that there could be manufacturers out there putting a recommended pressire on the sidewall BUT I haven't heard or seen it and there are a LOT of tyres I haven't had anything to do with

[Dhuck]

No... Sorry but IMHO you are incorrect there, Cobber, because the manufacturer doesn't know what the tyre is going to be fitted too, Surf, Frontera, Rodeo, Navara, Patrol, Hummer, Dyna, Hino, Fuso...

From Hankook website- "In addition, the maximum inflation pressure for safe driving is marked on the tyre sidewall"
From Michelin website - "...on the tire side wall shows the max allowable inflation pressure."
From Cooper website- "Do not exceed the maximum pressure indicated on the tire sidewall."
From Kuhmo website - "Do not exceed the maximum inflation pressure labeled on the tire sidewall"
etc etc they are direct quotes from the Manuf (pls excuse some paraphrasing).

There are mobs (and my local Bob Jane is one of them) who told me and other family to ignore the pressure as it is just a manuf recommendation. IMHO grab your money and run do not walk to another supplier if any pimply faced d1ckhead tries to tell you that... or better still try a Warranty Claim.

However... I MUST add one disclaimer in that there could be manufacturers out there putting a recommended pressire on the sidewall BUT I haven't heard or seen it and there are a LOT of tyres I haven't had anything to do with

Over 20 years I have had in the industry. But as your signature says.

[YNOT]

Where the side wall of a tyre is marked "maximum inflation pressure", it is exactly that, a maximum. That does not mean you should inflate your tyres to that pressure all the time. The correct pressure is dependant on many factors, load, speed, terrain, tyre type/construction, etc etc. There is no easy answer to the question of "what pressure should I run", you need to take into account all of the factors above.

Tony

[Maxhead]

Where the side wall of a tyre is marked "maximum inflation pressure", it is exactly that, a maximum. That does not mean you should inflate your tyres to that pressure all the time. The correct pressure is dependant on many factors, load, speed, terrain, tyre type/construction, etc etc. There is no easy answer to the question of "what pressure should I run", you need to take into account all of the factors above.

Tony

Thats what I thought the 4/6psi rule is for, but as others say don't use it as its for the older tyre types....very confused

[YNOT]

I've never tested the 4 Psi rule so I can't really comment on it, but as a rule of thumb it's probably not too far off the mark.

Tony

[Maxhead]

I've always used it as a guide as all tyres are different and never had an issue with tyres wearing badly...I think stick with what works.

[the evil twin]

Over 20 years I have had in the industry. But as your signature says.

The comment was referring to the pimply faced d1ckhead at Bob Jane T'mart (or Tosser Mart) who would have been lucky to have 20 weeks experience. I don't trade or direct insults at Forum members so no offence intended personally however I am a bit taken aback that you agree with him.

With "20 years in the industry" I would be interested to here your expert opinion (not having a shot) as I consider anyone with 20 years experience to be expert. :icon_driving:

Please note - as in prev post I am specifically referring to the "Max inflation pressure" moulded on the tyre sidewall meaning that and nothing more as per my manufacturer references. I was NOT referring to the load and speed rating code information.

So in the interests of clarity for the discussion is it your expert opinion that it is...
acceptable for customers to use a standard inflation pressures higher than the maximum stated by a manufacturer, and
You or your business would have no issues with a warranty claim?

I was going to have a sig of "I'm not very smart but I know stuff" but it seemed a bit egotistical :icon_bonk:

[89GQ]

I've always used it as a guide as all tyres are different and never had an issue with tyres wearing badly...I think stick with what works.I too use the 4psi as a guide and think it works!!?? Dunno, but my tyres are wearing well and eavenly im'e on 36 psi Cold

[Finly Owner]

Why fix what ain't broke?

[89GQ]

Why fix what ain't broke?Spot on!! When i was running mine at 40psi cold! there was feathering on the edges of the treads, tyre shops i went too were as confused as me! even the rears were doing it! worked out 36 cold with the 4psi rule and now even wear on all!! But yeh all tyres are different.

[chrissey]

Hey guys,
Well I ve looked around the Forum and I am even more confused now. I ve got a GQ with Maxxis Bravo 751 tyres. It says 41psi max on the tire, when I bought the car they were on 25 psi, i brought them up to 38 as I mostly do highway driving at the moment....Does that sound about right too you? Sorry I am well confused after reading this thread haha.
Thanks
Chris

[Gert B Frobe]

When i took delivery of mine the pressures were at 46! These are Bridgestone 693 as per manufacturer.

I run them at 38 and find i get the best feel and response.

Previous to these i have used Cooper ST and ran them at 36 for on road and that seemed to be a happy medium (vehicle was a dual cab ute smaller than the wagon).

[TCgolfer]

Welcome mate. I'm a newbie too!
I recently switched to KM2' 33" and with the stiffer sidewalls than the previous Pirrelli ATR mean I am running a little softer now. 34 front, 32-36 rear depending on load.
I also purchased a tyredog TPMS system for $175 and I can say well worth it. When you look at what tyres cost! Cheap piece of mind.
Just got back from 4 weeks outback and met many who blew tyres from slow punctures then bang. Being able to see what the tyre temp and pressures are doing in real time is almost hypnotic. You soon learn what's working best for your rig in different condition.
Hope this helps.

TC