All y'all with Nokian WR-SUV and WRG2-SUV's, what pressure do you run them at? Since they're a higher pressure tire maxing out at 51 psi I usually run mine about 42 psi. It sounds high but I've found that if I let it drop much below 40 the car seems really sluggish and the steering feels heavy. What do the rest of you run yours at?

All y'all with Nokian WR-SUV and WRG2-SUV's, what pressure do you run them at? Since they're a higher pressure tire maxing out at 51 psi I usually run mine about 42 psi. It sounds high but I've found that if I let it drop much below 40 the car seems really sluggish and the steering feels heavy. What do the rest of you run yours at?

I run mine 0.5-1.0 psi above stock recommendations front and back. no issues with handling or steering.

We run Patty's at 35 front 38 rear.

Love the more solid road feel.


Dom

WR-SUV's on the Element

WRG2-SUV's on the kids Ford Escape

Both 235/70-16

Both at 40 psig. :-)

I'm sensing some difference of opinion here...:roll:

So I was expecting more of a consensus but there's a pretty wide range. Anybody with more input?

I'm sensing some difference of opinion here...:roll:

So I was expecting more of a consensus but there's a pretty wide range. Anybody with more input?

I've always played with tire pressure for several hundred miles before settling on a set pressure. I go up in .5-1.0 increments. I find higher pressures far too bouncy for me. I have had the back end unsettle in turns so I drop the pressure and take the same turns over and over until i get it settled. I used to do this with my race cars and just always did it with my street cars/trucks.

...I usually run mine about 42 psi. It sounds high but I've found that if I let it drop much below 40 the car seems really sluggish and the steering feels heavy.

I don't have Nokians, but I agree with this statement for all 3 brands of tires I've run on my E (factory Wranglers, Cooper ATR, and General HTS).

Not that the steering is really heavy or bad at 35psi, it is slightly heavy but generally "ok", but I like/prefer the lighter-quicker feel around 40-42psi. I run my HTSs at 40psi all around.

I think increasing the front maybe 5psi over "recomended" makes the bigest difference. It is hard to tell if the rear is at 35 or 40, but I go with the 40 anyway. In the front you can really "feel' the difference. Tire wear has been fine.

Experimentation is a good idea. Changing tire pressures is a free and easy performance/feel improvement.

I've been watching mine for wear at 40-42 and they seem to be wearing just fine, especially considering the extreme mileage I've been putting on lately.

I've always played with tire pressure for several hundred miles before settling on a set pressure. I go up in .5-1.0 increments. I find higher pressures far too bouncy for me. I have had the back end unsettle in turns so I drop the pressure and take the same turns over and over until i get it settled. I used to do this with my race cars and just always did it with my street cars/trucks.


I do the same thing Larry. I think that comes from a racing background.

I would do that with every set of new racing tires, on each track. That's what the practice laps are for.

I still do it with the street tires on all my cars. It's important to have the car slide in a controllable fashion. The preferences in that area varies widely from driver to driver. I know what I like, and shoot for that same handling characteristic in all my cars. I find the higher inflation on the Element produces a rigid ride, and premature rear end slide at higher speeds. Wile at the same time, being the cause of front tire slide, under heavy/fast stopping conditions. I don't like those traits at ether end of my car. It just does not suit my driving style.

Conversely, Lower inflations allow the tire to become to mushy. you wind up riding on the sidewall in tight high speed turns. That's never good. The sidewalls don't have much grip, and no tread at all. That and when doing a fast stop, the weight transfer becomes lopsided to front bias. If your in a turn the back end is lost, with no hope of recovery.


Dom

The max pressure marked on the tire shouldn't affect the appropriate pressure for you vehicle. This really depends more on the tire size (air volume) and the vehicle weight. 32/34 is what Honda determined was right for the 215/70/16 tires - hard enough so the tires did not flex too much and blow out, soft enough to be comfortable (and to avoid blow out due to impacts).

Beyond that it is more a matter of handling, mpg, and tread wear.

Many have found that the Wrangles wear too much on the shoulders, and high pressure helps shift that wear to the center. I found 2-4 psi above recommended shifted wear too much to the center on my Cooper ATRs (225/70/16), though it did reduce steering drag (blocky shoulders).

So I think previous discussions about tire pressure apply, regardless of the tire model.

I would think that compound type and stiffness would also be a factor?

I would think that compound type and stiffness would also be a factor?


In fact they are component of handling in any tire. That's the reason for doing the inflation exercise with each and every tire change. The same brand tire in the same model and size, often varies in compound consistency from run to run, and year to year.

When racing you always insist in having tires from the same run. ( Keep in mind that racing tires are not always the same size on all 4 wheels. ) In oval racing we often ran a Goodyear glass belted 60 series tire on the right rear. It has a tendency to stay flatter in the tread area than a radial tire on a banked track. Then run radials on the other 3 Connors. Just to give you an idea how much of a factor it is.

In sports cars, the rears are usually wider than the fronts. Sometimes a larger diameter also. Depending on the rules for that class of car . Still when obtaining race rubber, you want the tires to be from the same production run. ( I still insist on that for my street tires. Thank God I have a tire shop that humors me. )

It's not so critical on a street car, but still has some overall effect on the handling.



Dom

From the Nokian website
http://www.nokiantires.com/check-tyre-pressure
1. The correct inflation pressure is provided in the owner's manual of your car.

From the Nokian website
http://www.nokiantires.com/check-tyre-pressure

Yes, but isn't that only applicable to the OEM 215 tire with a load index of 99 ?
I think a lot of us are running the Nokians at least 1 size up if not 2 . . .

The Nokians in a 235 are rated at 105 load index with a higher max pressure than the OEM GY Hp's (51 vs 44 psi). Why not take advantage of the tire design and use a pressure that is more in line with the optimum handling characteristics of the tire? Plus , you get more load capacity to boot . . .

The sidewalls of my G2's are marked for 32-49 as the desired range with a 51 max.

Another rough way to look at it is :

OEM 44 max/35 specified = 1.285 max-to-optimum ratio

NEW higher rated tire 51 max/1.285 = 39.6 psi ~ 40 psi :-)

The minute you change tire sizes and/or load ranges, the door placard may no longer be applicable.

Another interesting thing ??

The Nokian G2's we put on the Escape a few months ago are stamped "made in Russia" . . . the original WR's on the Element added in Oct of '07 are stamped "made in Finland" :|

Y

The Nokian G2's we put on the Escape a few months ago are stamped "made in Russia" . . . the original WR's on the Element added in Oct of '07 are stamped "made in Finland" :|


That is Interesting! Russia, Who would of thunk it !

I'm not sure I subscribe to all of the other theory's you posted though.

Keep in mind that the Element has a weight issue to contend with. Over inflating a tire with heaver sidewalls may serve to compound an issue, not solve it. That's the reason to do the inflation testing. To See exactly how the car responds to the the changes in the pressure. Every vehicle responds with a varied mix of stability and traction thresholds. Testing is the only way to verify the precise inflation for your car's unique balance. It is also a fallacy that what works well on my car, with my driving style, is what you should run on yours. The factory inflation numbers are given as a guideline more than a hard fast rule. They will work fine for 99% of the drivers. For those of us that "sometimes" ask our cars, to do things that they were not designed to do, then go the extra mile with inflation testing.

Run the tests yourself. It can't hurt. The cost is some time and some gas. The benefits are higher quality ride, improved handling in emergency conditions. Pace of mind!

Dom

I would be curious to see how individual preferences correspond to tire sizes (and the corresponding load indexes)

I bet the guys running 215/70-16 Nokians find the middle 30's work best.

225/70's a little higher . . .

235/70's even higher (like 40 psi)

Is the max psi on the 215, 225 and 235 sizes the same (51 psi) ? . . . can't really glean that info from Nokians on-line info ??

If you put a wider tire on, and over inflate it, you lift the shoulders, putting more wear on the center tread. In addition, you are not taking advantage of the wider tread.

Another way to put it - tire pressure and vehicle weight are two main things determining the contact patch area. The higher the pressure, the more rounded the tire, and smaller the contact patch. Just because a tire can take 50psi, does not mean you should run it at the pressure - unless your load matches.

As best I can tell, if your tire has a higher load rating, it really should have less pressure than recommended for stock. Conversely if you put a wide, but low profile tire on the Element (and hence lower load rating), you should run higher pressure - enough to properly support the car.

As I mentioned earlier, with wider AT category Coopers, I got excessive center wear, meaning that I was running them too hard.

My 97 RAV4 takes the same 215/70/16 tires, but Toyota recommends 28/26 psi. Since the RAV is some much lighter than the Element, that is plenty. At the lower pressure the deformation of the tires is about the same as on the Element.

If you put a wider tire on, and over inflate it, you lift the shoulders, putting more wear on the center tread. In addition, you are not taking advantage of the wider tread.

Another way to put it - tire pressure and vehicle weight are two main things determining the contact patch area. The higher the pressure, the more rounded the tire, and smaller the contact patch. Just because a tire can take 50psi, does not mean you should run it at the pressure - unless your load matches.

As best I can tell, if your tire has a higher load rating, it really should have less pressure than recommended for stock. Conversely if you put a wide, but low profile tire on the Element (and hence lower load rating), you should run higher pressure - enough to properly support the car.

As I mentioned earlier, with wider AT category Coopers, I got excessive center wear, meaning that I was running them too hard.

My 97 RAV4 takes the same 215/70/16 tires, but Toyota recommends 28/26 psi. Since the RAV is some much lighter than the Element, that is plenty. At the lower pressure the deformation of the tires is about the same as on the Element.


Thanks Paul!

That is exactly what I was attempting to convey. You nailed it with that!

Dom

so would a straight edge laid across the width of the tire be useful for looking at over inflation?

edit.. never mind. I just read about using a chalk line to look for proper inflation. Kind of like a using a soft straight edge.

so would a straight edge laid across the width of the tire be useful for looking at over inflation?

Not really....there is no weight on the "top" of the tire. (Where you could put a strait edge). The bottom of the tire is the contact patch. ;-)

You can put wide chalk (kids sidewalk type is good) or paint marks accross the tread....and take it for a spin. It will wear off in some spots and remain in the spots that aren't making contact. Don't accelerate or brake real hard, but go thru some twisty turns.

http://www.jeepfan.com/tech/TirePressureChalk/TirePressureChalkLine.jpg

An empty parking lot and a portable air compressor are very handy for this.

http://www.fjfan.com/technical/tirepressure/TirePressureCutAway.jpg
Under inflated....over inflated.....and just right.

You can also pay carefull attention to tire wear...but it'll take longer to notice a difference.

Remember, an underinflated tire is more prone to hydroplaning and can reduce gas mileage. I'd rather be slightly "over" than "under."

Remember, an underinflated tire is more prone to hydroplaning and can reduce gas mileage. I'd rather be slightly "over" than "under."


Under inflation also leads to heat build up from excessive flexing. The Firestone/Ford recall is the best evidence to that fact.

Dom

. . . Testing is the only way to verify the precise inflation for your car's unique balance. It is also a fallacy that what works well on my car, with my driving style, is what you should run on yours.


I agree . . . with the Element, most everyone that is going wider, heavier and taller seems to bump up the pressure a few notches to improve things.

The beauty of having a higher load rating is it can give you more "wiggle" room, especially if that rating comes with a wider range of usable inflations (like the Nokians)


The factory inflation numbers are given as a guideline more than a hard fast rule. Dom

I would agree only if you don't go below the minimum load ratings on the door placard. ;-) The other thing about the Nokians, is they are NOT a "P" metric tire and don't exactly track the US P metric ratings (they conform to the European Tire standards) . . . the load vs inflation curves are a little lower than the US curves so you should probably be adding a couple psi to the placard #'s when using the Nokians (apples-to-apples, in the OEM size).

I almost sent my first set back because "they had no "P" !! " lol. Drove the Tire Factory guys nuts until he explained things :-D

Just curious, what size WR's are you running ? With your pressures optimized in the middle/high 30's I'm guessing you are running stock 215's or 225's but not 235's ?

. . .
As best I can tell, if your tire has a higher load rating, it really should have less pressure than recommended for stock.

Yes, but I bet you would have a really difficult time finding that in writing from any tire manufacturer . . . ;-)

Yes, but I bet you would have a really difficult time finding that in writing from any tire manufacturer . . . ;-)

and I don't follow that advise myself. I've switched back to OEM style Coopers in the 225 width, and I still run them a bit above sticker.

On other threads we have found tire size and load v pressure tables, but the numbers all apply to bigger vehicles. While 35 psi is a good median pressure for passenger cars, pickups and suvs, real trucks (and rvs) have pressures in the 50psi or higher range. Trucks can also vary widely in gross weight, depending on the load.

It is worth keeping in mind that the stock tires have a load rating of 1700lb each - 4x1700= 6800, well above the weight of the Element. I believe the stock tires say 'max load 1700 lb at 44 psi'. In other words, if you load your E down with 2500 lb of cargo, you should raise the pressure to the max!

... In other words, if you load your E down with 2500 lb of cargo, you should raise the pressure to the max!

...and enjoy your newly crushed suspension? :roll:

Someone on Expedition Portal has posted a pressure adjustment table from Discount Tire
http://www.expeditionportal.com/forum/showthread.php?p=560829#post560829
http://www.expeditionportal.com/forum/attachment.php?attachmentid=37482&d=1265678829

According to this table, the stock tires, with load rating of 99 are inflated for loads of 1548 and 1615 lb (32/34 psi).

For 225/70/16 tires, the rating is 101, and corresponding pressures are 29.5 and 31 psi, 2-3 psi under sticker. 235's at 104 are even lower, around 28psi.

This table supports my contention (see earlier posts) that larger tires should have less pressure. However, I don't plan on lowering the pressure on my 225's anytime soon.