The safety related question is "How are you going to cope in the event that you suddenly find yourself in over your head?". Or, when you most need the car to be predictable, will it be so at the level involved? This could be well below the ultimate limit. You already know that you're quite uneasy with 40 psi all around for a number of reasons. Now imagine the same inflation pressures and having to suddenly slow down on a tight and slightly bumpy off-ramp curve.

For anybody who normally drives mildly to moderately, I'd strongly recommend staying close to the OE recommendations. Those who regularly explore substantially more of their cars' capabilities can be expected to eventually develop enough experience and "feel" to deviate a little further. That does sort of tie in with the concept of tuning for "preferred behavior in the regime that you mostly drive in", in that the normal range of driving intensity is somewhat wider for the hard driver and the gap between normal driving and limit behavior is somewhat smaller. I'll add here the strong caution to avoid overestimating one's abilities.

But then, I read another article that actually advocates leaving pressures at around 35-38 PSI (if normal is 31-33). Why? it's a safety thing again: so many people neglect checking pressure for so long, the idea is to delay when the pressure drops to into the extreme hazardous range of the teens that much longer. Go figure!

That's scary, for that much extra pressure to be (apparently) publicly recommended without regard for individual drivers and vehicles. All in deference to lowest-common-denominator mentality in not making such a simple check. Aaaaarrrggghhhhh!!!!

Norm

 

But that's what "public safety" is all about... reducing everything to the lowest common denominator.

Buddywh

 

I'm just sorry I didn't learn all this sooner. I too am one of the "myth" believers who really didn't know jack about what I was doing to my car or risks I've been taking. I figured 43psi F/R cold pressure(44psi rated MAX pressure on the side wall) with typically 2.5 people and moderate luggage was my best choice in pressure, since it's all hwy travel and I was more interested in reducing rolling resistance to make the high speeds easier on the engine. I don't really care about fuel economy or tire life, just engine wear.

Now I realize, I regularly like to push the canyon corners for about a 20-mile section of my monthly 380-mile trip, which never "scared" me, but felt a little twitchy. I just figured it was the floaty suspension and that I needed a FSTB, RSB, and to lower the car some or at least do near speed limit. I'm betting HIGH tire pressure is adding to the feeling.

My car sees pretty much 95+% hwy travel at an average of 80-95mph. However, I pretty much ALWAYS have 40+psi, when I actually drive the car around town. I knew the crappy ride was aggrevated by the higher pressure, but really didn't think it would make that much difference. Now I realize, I've been playing with fire and should IMMEDIATELY drop to 1-3psi ABOVE manufacturer specs(32psi?) F/R for my stock 17" blowtenzas.

Now that you've guys made me realize how STUPID I was being, it will be corrected as soon as I get home.

BTW, I have pushed the car to it's limits and slightly beyond once or twice. At least enough to start sliding(pushing?), but at VERY low speeds on a switchback with decreasing radius corners. It felt very controllable, but of course this has NO relevance to emergency high speed handling. I just thought I should try and as safely as possible feel what the car does when it begins to "let go".

Questions:
--------------
1) How do I know what tire pressure to run once I upgrade to say 18" or even 19" rims and tires?

2) How will I know what tire pressure is applicable for MY vehicle when all I'll have is the MAX pressure on the side of the tire?

I will keep the overall rim/tire diameter as close as possible to OEM to keep the speedometer accurate.

AWESOME debate guys!

 

Ok, you don't have to be a ****** about it! Why so snappy?

 

i never knew i could start a thread that would become so BIG!!!!..i am not even keepign up with this thread anymore....this is so cool!

 

Thanks for the post!!!!!!!! Makes me feel that not every word has been wasted. I really appreciate the feedback. So many assume that maximum sidewall pressure is the ultimate in handling. In fact, it is the maximum hot pressure the tire can stand!!!!!!!!!!!!!! A legal warning really! And a hot pressure limit!!!!!!!!!!!!!!!

It is very hard to really balance a car and I repeat - manufacturers are pretty close to being right. Without training, a test facility - (I know you don't want to hear that, but it is true), it is impossible to really set your car up beyond what the manufacturer has recommended. If you look at some of the posts, the pressure suggestions are impossible - simply stupid - yet believed by their authors. Those recommendations are the results of beginners who havn't crashed yet / nothing more.

Regarding bigger tires. The Maxima really doesn't handle very well. It lifts a rear tire when cornering and is somewhat unstable. So I question a move to bigger tires when so much more needs to be done to make it stable. IN SHORT - Why - bigger tires or low profiles with a marginal handling vehicle??? You don't have much to gain! Big bucks/ little or no gains. WHAT WOULD BE BETTER IS A WAY TO TAME THIS INSTABILITY. If one is after "cool looks" - I guess ultra low profile tires meets the current standards. Looks good performs little better--- being the current fad. Tires help a good handling vehicle perform significantly better but, to a much lesser degree, do great tires help a poorly handling one. The Maxima, at least in 2000, is very marginal in its handling. Save your money on larger tires unless you are looking to impress the uninformed.


Larrfry

 

No, thank you for the reply. It's definitely NOT in "vain". You will NOT hear from at least 90% of the people who will value and appreciate your information. We here at the .org have a habit of only responding when we DISagree or feel the need to flame, so if you only get a limited response(mostly by flamers) do NOT think your posts are in vain. Lots of others(myself definitely NOT included), prefer to only read/learn from the wealth of information here and stay out of the cat "fights" and debates.



The bigger wheels are for looks mostly. The low profile is also mostly for looks, but mainly to keep the overall diameter the same to keep the speedometer and odometer accurate at least until the warranty wears off.

So with a different brand, but same spec tire for my stock 17" rims, should I still run the FACTORY recommended pressures? I'm sure this is what you've said, but I'm just double checking, since I'll probably need another set of tires before I go with 18-19" rims/tires and all I have to go with is the MAX pressure on the sidewall.

Once I go bigger, how do I know what psi to run since the FACTORY recommendations won't apply? I don't mean optimal for performance, just safe. Do I look at what the tire manufacturer recommends and then try to guesstimate according to what Nissan recommends for a Maxima according to it's load capacity?

Thanks.

 

 

Totally agree. No problem. If you really want an intelligent debate, go make up some BS story about how synthetic(particularly AMSOIL) suck and post it in the General forum. Just kidding, but I've learned more than I've ever cared to know debating with some of the "oil" gurus.


Got it, thanks.

Looks and maybe a little function. Supposedly with 8" wide aftermarket rims, I can safely run wider tires and SHOULD have better grip in corners and launching at the track. However, if I my new rims/tires add more unsprung weight it'll probably be counterproductive on braking, acceleration, and handling, but that's the price I'm willing to pay for losing the common Maxima look.

Man that's scary. I've been running 43psi cold F/R! Who knows how hight the HOT pressure rose, while I'm crusing at 85-95mph. I've even ran up to 130 and 142+ once each, without even considering it.

One more question:
Would an Infared Thermometer allow me to "test" a few tire pressures once I get 18-19" rims and lower profile tires? If so, what would be some valid/conclusive tests to perform? I'd like to see what's happening to my tire pressures while NORMAL driving at hwy speeds at least. Actually, I'll probably get the "Smart Tire" tire pressure monitoring system once I change tires, so that would be easier to monitor and study.

 

A little earlier in this thread was a link I posted to a site that covers, in detail, the process for finding optimal pressure, under track conditions, by measuring tread temp's. This guy's article (the whole site, actually) is very informative.

Over simplifing the article: you exercise the tires hard, and sustained. Then measure the temp's of the tread surface to ascertain if 1) all tires are working equally hard and 2) the contact patch is equal to the tread area. This all requires a good track so you can avoid worrying about traffic. And all this does is find a pressure where the tires work optimally (not necessarily handle optimally... or safely) on that track! There is much more involved to get the car to handle well.

I think the gist of this whole thread comes down to: if you aren't driving under track conditions, why even try to find an optimal high(er) pressure for handling purposes? The mfr's suggestion is the safest, so stay within a few pounds of that. BUT, the situation you have is interesting, and really applies to everyone else with big wheels/low profile tire combo's (or getting them).

I would ask the question like this: is the data plate pressure still correct for these wheel/tire combo's? if not, how to determine it?

BuddyWh

 

A pyrometer reading is a fine tool for a racer after a few Hot Laps, if read immediately. It will NOT help in street driving

 

Wish BuddyWh had responded. I think it is important once one expresses a view to either defend it or say " I made a mistake".


Larrfry

 

Hi Larrfry --

I saw this in one of your previous posts:

"Regarding bigger tires. The Maxima really doesn't handle very well. It lifts a rear tire when cornering and is somewhat unstable. So I question a move to bigger tires when so much more needs to be done to make it stable. IN SHORT - Why - bigger tires or low profiles with a marginal handling vehicle??? You don't have much to gain! Big bucks/ little or no gains. WHAT WOULD BE BETTER IS A WAY TO TAME THIS INSTABILITY. If one is after "cool looks" - I guess ultra low profile tires meets the current standards. Looks good performs little better--- being the current fad. Tires help a good handling vehicle perform significantly better but, to a much lesser degree, do great tires help a poorly handling one. The Maxima, at least in 2000, is very marginal in its handling. Save your money on larger tires unless you are looking to impress the uninformed."

If I read this properly, your position is that whether or not a tire/rim combination on a 5th Gen Maxima is out of spec, you would NOT recommend running a tire larger than the OEM size of 225/50R17 for handling reasons alone. Is that correct?

 

Hmmmmm. No comment, Larrfry?

 

I thought I responded TO YOUR PREVIOUS EMAIL (including your private emails asking for my support??)

Maybe not.

In short - I'd never violate the manufacturer's recommendations without EXPERT knowledge. Regarding handling - I don't think there is much to gain with wider tires but a wider tire always affords some degree of better handling in the dry - asumming the tire stays on the rim!!! So in theory, yes - a wider tire is better in the dry but it may be completely unsuitable to the rim and therefore dangereous.

I think the instability of the Maxima is a key issue in getting this car to handle and larger tires (within/without the manufacturer's specifications) will NOT produce significant improvements


First - y2kse - has done a great deal of research - and I respect that. I don't have any expertise on rim/tire size except that I would respect what the manufacturer said as well as what tire companies and wheel manufacturers have said. I certainly have no special expertise in that regard and would look to what the car/tire/wheel manufacturers had to say. Thankfully, y2kse has done the researcH!! Every source supports y2kse's position!!!! I GUESS IF YOU HAVE EXPERT KNOWLEDGE, VIOLATE That data BUT THEN TELL US WHY.

Regarding wider tires in general, forgetting whether they fit on the rim or not, they have to give marginally better acceleration or cornering in the DRY!!!! In theory, that has to be true but ignores the very significant problems that y2kse has raised regarding overSize tires!!!!

Secondly wide tires produce VERY negative results in the rain!!!!! Hydroplaning is a result of tire pressure and tire width - largely. Also with a car like the Maxima , which has significant problems cornering and really isn't capable of accelerating aggressively because it is front wheel drive - I question any emphasis on larger/lower profile tires. Very little to gain by changing the tires - period.


Larrfry

 

Pushy!!!!!!!!!!!!!!!!!!!


I don't read the posts on a daily basis.


I support your general views regarding oversize tires -- they are well researched. But please don't put words into my mouth!!!!!!!! While I support your general premises, I resent your public/private emails that attempt to dictate my position.


I'd predict some flamming now.

 

I'm not a flamer, Larrfry. I've learned that if someone is going to build a resentment, it's better to give one that to get one.

Thank you for supporting my position.

 

Happy to be wrong!!!!!!!




Larrfry

 

 

No mistakes made... I stand by what I said.

The problem is... Yokohama has changed their site and I can't find the load/pressure tables for my tire anymore. This seems to be the problem with most p-metric tires: there seem to be no published pressure/load tables, unlike LT tires which mfr's do publish.

Your argument for not straying far from the vehicle recommended pressures seems to be one of assured safe handling. I agree that is a good rule to follow if not also straying far from nominal loading.

My point is that, operating within the bounds of the tire's max pressue at top and the mfr's rec'd pressure, the vehicle is perfectly safe, except with regards to handling.

So consider the following: when four adult passengers and their weekend luggage are loaded into a Max, that handling has been severely affected. This is the baseline from which we are operating: a severely compromised vehicle. Is the car overloaded beyond the GVWR? probably. Is this commonly done? all the time.

What has also happened is, under the greatly increased load, the tire sidewall flexes more and the tire heats more. This temperature rise leads to early tire failure and tread separation at highway speeds. In order to maximize tire performance/life, the pressure has to be increased. You can ignore this principle if you want, but it is clearly evident the safety margin inherent in the original pressure recommendations has been greatly reduced by the extra load. To suggest otherwise is irresponsible.

Furthermore, increasing pressure can only improve handling from the greatly compromised handling situation you started from as sidewall flexure is reduced. Not to that of a lightly loaded vehicle, but we aren't doing this to facilitate auto-x performance, we are doing this to allow a loaded vehicle to travel to it's destination without an accident due to tire failure.

And my observation from any vehicle I have ever owned: handling was/is very bad with a heavy load, just in normal maneauvers. When I increased tire pressure handling always, without fail, got much better and I'd feel safe again on the highway.

I am not saying to exceed the "max pressure" imprinted on the sidewall as you suggest: that is an absolute limit never to be exceeded, cold or hot. And, in fact, one rarely has to get to that point but should feel free to increase pressure to it in order to guarantee their safety on the highway, especially if they aren't sure of their load but know "it's a lot".

After all, that's why it was put there in the first place (and not to make the oil change guy's job easier!)

Finally, IIRC from the tables, in order to operate my Max with the Yokohama OE tires at GVWR I had to run at 35psi which is well above Nissan's recommended but still well below the max pressure on the sidewall, and also well below each tire's max load. I can effectively increase the GVWR of the max simply by increasing the tire pressure further.

BuddyWh

 

They must exist!

 

But not accessable.

Contrary to any opinion you may voice, increasing tire pressure is the safer for load carrying. It is not a myth no matter how you may like to make it so.


And please, quit trying to imply I am saying to operate beyond the max pressure when I have clearly stated that it is the max pressure whether cold or hot.

BuddyWh

 

And it WAS lawsuit city... have you forgotten the Firestone/Bridgestone Ford debacle?

Buddywh

 

OK... I finally found the table I was previously referencing. It was posted in another thread by Norm on the org. AND... he revised it later to change the absolute pressures to relative pressures.

What I was doing then was reference my LI 91 tires' rating of 1366 lbs to that table. But for the reasons Norm stated when he revised his posting, that was incorrect.

So, based on what I now know, 1366 lbs would be safe, and give good margin for my front GAWR, at 35psi. But I do NOT know how it compares at 32psi! On your assurances, I suppose I should feel comfortable that Nissan wants to minimize their exposure and will have spec'd it correctly. Like Ford did with Explorers.

I still stand by the premise of my statement: it is safer to increase pressure when loading a vehicle. Even if not necessary, it poses by far the lower risk vs. NOT increasing pressure and running under-inflated for the load. There is NO DOWNSIDE to doing so and much safety advantage to be gained.

This is what the ITRA has to say about the max-pressure being present on the sidewall as they defend keeping it.

http://www.itra.com/NHSTAtirelabeling.html

"We clearly understand that the maximum inflation pressure marked on todays tires is normally higher than the recommended pressure. However, in most cases, it is not high enough to create major problems, and it presents less risk than if the markings are removed from the tire and replaced with a load symbol that some people may not understand."

I observe that "some people" should be changed to "most people". I cannot find any decent information on the LI system, short of purchasing the commercial specifications.

BuddyWh

 

Sadly we have a "****ing contest" going on here.

The Ford/Firestone debacle, having listened to almost the entire testimony was one of Ford blaming Firestone, and Firestone blaming Ford. Firestone blamed Ford for trying to use as low a tire pressure as possible (presumably for ride comfort) that still met the FULL Load rating of the Firestone tire with almost no margin for error. In short , from Firestone's point of view the tire was loaded at absolute maximum with zero room for error. In fact, a higher pressure was recommended by Firestone to Ford.

Ford said their recommendations met the load specs of the Firestone tires. They also noted the tire were often defective. The tires in question had a statistically higher failure rate.

The Ford debacle was, in my view, the result of three causes.

1. Pressure specifications were at the limit for a full load as recommended by Ford

2. Defective tires produced by Firestone

3. Users who never checked their tire pressures, allowed them to run low, and also ran with full loads.


Absent any other data - that is a pretty unique set of circumstances.

That still could be viewed as an endorsement for higher pressures with full loads but it ignores the fact that many manufacturers have already provided a great deal of excess capacity for a full load in their tire pressure recommendations to begin with. A tire chart will tell you all you need to know. More importantly if you start raising pressures indiscriminately you could easily create a vehicle that handles so badly it wants to have an accident.

I wish the world was so simple that if you raise tire pressures really high, you will be safe. Not the case - you can really create a bad handling vehicle with indiscriminate pressure changes!!!!!!

 

Sadly another ****ing contest


I'll ignore the fact that you originally thought and even posted your opinion that your Yoko Avid V4 tires couldn't meet the maximum design load that Nissan specified for the Maxima unless they were at 44 psi!!!!!!!!! Now it seems you are sure this was wrong and there is a great deal of margin for error at much lower pressures. In short your recommendation of 44 psi as a minimum pressure, even for full load, was in error by a large amount!!!!!!!!!!!!!

You've now changed your opinion, no problem, except I wish you had added an apology or an edit to your previous post.


Regarding whether I misrepresented your position regarding "max pressure whether hot or cold". If I did, I apologize. I simply don't understand the "hot or cold" references - completely wrong. Apples and oranges. Cold is as close as it gets to a universal standard for good reason. It's repeatable. If you drive, tire pressures can jump 3 -5 - 7- 10- - or more in psi. So I really have trouble with you talking about pressures "hot or cold" like they meant the same thing. That was confusing and you never offered a warning to readers.

 

Max pressure is imprinted on the sidewall for a variety of reasons. One critical user is a tire "professional" for mounting tires. When first mountng a tire, they frequently over-pressure (vs. operating pressure) setting the bead... they must not exceed that pressure. Cold.

When traveling on the highway one should check tire pressures at fill-ups. If ever above the pressure, for whatever reason, it must be reduced to or below that pressure. Hot.

Never exceed, cold or hot. Get it?

It shouldn't be a contest of any sort, it's a simple matter of safety. It is extremely common to see overloaded vehicles on streets, but it is much rarer to see extreme auto-x handling maneauvers attempted. For public safety reasons, it just makes good sense to advise adding a few extra lbs when loading a vehicle heavily.

BuddyWh

 

So 62.5lbs hot fronts is a bit high right? Just got through reading all the posts and had to chime in.
You really don't want they pyro readings...

 

Ok - you now recommend we check our tires at every rest stop. This is unbelieveable!!!! I gather you have now realize that hot pressures are very different from cold ones. That is an improvement over your earlier posts of 44 psi which could Not have been more wrong!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Very dangerous in fact.

So you are now aware that cold pressures are not hot pressures and also it appears you now realize that the maximum tire pressure embossed on the sidewall of the tire is an absolute max!! A step in the right direction!!!!!

Now it appears you are struggling to figure whether cold pressures as recommended by Nissan adequately support a heavy load. You have misread tire charts before (as in your post of recommending 44psi) but now your position is that at 35 psi ( a rather dramatic change from your previous post of 44 psi) is fine, in fact, has a great deal of excess capacity even at full load by your analysis. You admit you are unsure whether 32 psi meets the same criteria because you don't have the data. Hmmmm - why express an opinion.

Correct me if am wrong but your current position is that somewhere between the manufacturers recommended tire pressures (which are cold) and the maximum pressures printed on the sidewall of the tire (which are the absolute maximums - presumably hot and very hard to determine) are the correct pressure Range and you also suggest we should adjust the pressures on a daily basis solely so as not to exceed the hot pressure (max pressure) limits!!!!!!!!!

Well, very crudely, you finally have figured out the broad range of tire pressures for the Maxima or any car. Now - how about handling and the best possible pressure RANGE when set from cold ????????????

I guess we could start again at "square one" in this forum, and maybe we should --- thanks to the confusion Buddy has created with his posts, which fragments the whole debate with his confused opinions/posts which lack any real understanding of the issues involved.

I'm not going to repeat all the other posts but I'd advise all to consider Buddy's opinions in light of all the information presented.

 

You are a sadly confused person who reads what you want to read, and remembers what you want to remember. Any conversation with you would be an exercise in futility. I can see that now.

Goodbye...

<plonk>

 

No - BuddyWh wouldn't want to see the pyro readings but I doubt he'd understand them anyway!

BuddyWh just likes to express an opinion -- no matter how little he understands the issues at hand.



I'm sure anyone, like BEJAY1, who has a clue, will have a similar negative opinion regarding BuddyWh 's posts !!!!!!!!!!!!!!!.

But I worry about those "innocents" who read BuddyWh and actually listen to him???


Larrfry

 

Perhaps....but you won't be surprised if I disagree.

Your various posts regarding tire pressures are filled with misconceptions, bad advice, bad research, and some fundamental misunderstandings.

Set the record straight if I, among others, are wrong. But please address all your opinions starting from your first post.


larrfry

 

Where can I get a good dial gauge. I want the kind that locks in the measurement until you press a button to release it. Those are the most accurate, right?

 

Consumer Reports did a test - sorry I don't have the data in front of me but do a search to see the results. I'm not sure dial gauges or electronic ones are more accurate than others. A few years ago I purchased a pretty expensive gauge made by Accu -something. It was not a wise purchase. I really tried to take care of it but it went out of calibration with the slightest bump.

I have three working gauges - two of a pencil type and one that is a dial gauge. They have read the same over many years. Most gauges seem accurate in my experience and only one gauge (that is the heavily advertised Accu - something)) failed almost immediately!. I'm working from memory but I believe Consumer Reports also found the Accu - something subject to easy MIScalibration.

 

You mean Accu-Tire? The little black digital gauges? Yeah those are horrible. I had one before. I have 2 pencil type gauges right now. I'm looking for a good dial gauge that locks in the reading.

 

No, he's referencing "TireGauge". If you drop them they will NEVER be accurate again. You can take it apart and fiddle with it till you get it relatively close, but it's never the same.

The BEST digital gauge available is supposedly AccuTire(Still looking to order mine). The "pen" gauges are usually pretty accurate and that's what I've been using, but ONLY the digital will allow you to read in 1/2 lb. increments.

 

Nissan requires that a special wheel adapter be used when balancing their tires. Many places do not have it, and make do, which results in poor tire balance.

My 1997 Max tire pressure label under center console lid states pressure s/b 29 rear, 31 front. If I put in more pressure, I get more vibration.

 

I have tested my accutire against a few pencil type and dial tire gauges, and every time, it was spot on. You must have damaged yours.

 

Radio Shack sells AccuTire gauges (with Radio Shack names on them).
They are on sale 1/2 price once in a while.
_BR

 

Read label on underside of the lid of your center console for stock tire pressure reccomendation.