# What tire pressure are you running? Nitorgen or air?



## DLORESKI (Apr 9, 2012)

My Cruze was dealer traded and the original dealer must have filled the tires with nitrogen because it has the green caps.
When I got the car it was reading 38psi. Now since are night time temps are in the 30's it has dropped to 33psi.
I thought Nitrogen was supposed to be more consistent with holding the same pressure during temperature swings? Is it ok to top the tires off with air now?
I see the label on the door says 38psi, but I haven't checked the tire to see what the max is.


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## McLoki (Apr 28, 2013)

I have not looked at the door. My tires are rated on the sidewall for 44psi cold. I typically fill them to 44-45psi on a cool day and roll with what comes. when they drop under 40-41 (or rise over 49) when the tire is cool - I readjust.


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## revjpeterson (Oct 2, 2013)

I'm running 37 at 30-40 deg. F. When warm or driving some distance it will rise to 41-42. I've also noticed that a tire in sunlight will usually rise 1-3 deg. above a tire in shade (for example when driving North-South mid-morning or late afternoon). Dealer said mine were nitrogen, but no green caps - perhaps for the sake of appearance. OEM Goodyears on the diesel are rated up to 51psi (not sure about other models), so anything up to that point is safe. Higher pressures will give better fuel economy, but getting too high will cause tires early wear in the center of the tire, so it's important to find a good balance.


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## obermd (Mar 3, 2012)

DLORESKI said:


> My Cruze was dealer traded and the original dealer must have filled the tires with nitrogen because it has the green caps.
> When I got the car it was reading 38psi. Now since are night time temps are in the 30's it has dropped to 33psi.
> I thought Nitrogen was supposed to be more consistent with holding the same pressure during temperature swings? Is it ok to top the tires off with air now?
> I see the label on the door says 38psi, but I haven't checked the tire to see what the max is.


Yes. This question comes up over and over. Basically, air is already 78% nitrogen and unless you have a serious need for it (aircraft tires, race cars, etc.) there is no real difference between nitrogen and air. Both gasses expand and contract with regards to temperature so there is no benefit here either. Where _pure_ nitrogen has an advantage is that there is no water vapor in it. Water vapor can lead to corrosion inside the tire, both to the rubber and the wheel. The corrosion on the wheel from water is minimal and the rubber compound in the modern tires is designed to resist environmental deterioration for at least 4 years. Note that I said _"pure"_. The only way to get a pure nitrogen fill is to mount and fill the tire in a vacuum chamber. I seriously doubt your dealership has a vacuum chamber for this purpose.

As to the max sidewall pressure, all the ECO trims, which includes the Cruze CTD, have Goodyear FuelMax Assurance tires put on them at Lordstown. The max sidewall pressure is 51 PSI cold. Run your tires as close to this pressure as you can tolerate and you will benefit from better fuel economy and handling. The downside is the ride gets stiffer. Car manufacturers select the door placard pressure based on comfort, safety, and performance. Comfort comes first. Safety and Performance go hand in hand - a better performing tire makes the car safer to drive by improving handling predictability. Modern radial tires will not excessively wear in the center when run at the max sidewall PSI as long as you rotate and balance them on a routine basis. Tires can also handle far higher pressures than the sidewall maximum so don't worry about blowouts due to over pressure.


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## oilburner (Jun 13, 2013)

I run mine at 45 an have free access to nitrogen where I work an I don't even bother. the only way to have 100 percent nitrogen ,you would have to evacuate the tire like doing AC an suck the tire down like a prune. people still pay for it ,we charge 4 bucks a tire.


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## JCarlson (Jun 11, 2013)

Another way to get _pure_ nitrogen is to be a chemical engineer and work with UHP (Ultra High Purity) Nitrogen all day long like me


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## XtremeRevolution (Jan 19, 2012)

JCarlson said:


> Another way to get _pure_ nitrogen is to be a chemical engineer and work with UHP (Ultra High Purity) Nitrogen all day long like me


Of course, you still have the vacuum out the tire before you fill it with Nitrogen, or you'll in all reality only get up to 86% nitrogen. It is difficult to get 100% nitrogen in a tire. 

Biggest reason NASA and the Military use it is because it is inert.


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## JCarlson (Jun 11, 2013)

XtremeRevolution said:


> Of course, you still have the vacuum out the tire before you fill it with Nitrogen, or you'll in all reality only get up to 86% nitrogen. It is difficult to get 100% nitrogen in a tire.
> 
> Biggest reason NASA and the Military use it is because it is inert.


How would you pull a vacuum on a tire? I have a multitude of fittings at home and work. And it is possible to pull too deep of a vacuum on the tire and actually damage anything?


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## Vetterin (Mar 27, 2011)

40 psi with air seems to work well for me.


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## Luigi (Jun 16, 2013)

I have been running mine at 46 psi. They can get up to 50 when in the heat and on the highway. I had them at stock for a 500 mile trip then pumped up to 46 on the return trip. Gained about 3-4% gas mileage and the handling is better. 

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## H3LLON3ARTH (Dec 16, 2011)

51 psi stock LRR

Sent From My Galaxy Note 3.
Which is bigger than my hand.


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## DMC (Oct 22, 2012)

Vetterin said:


> 40 psi with air seems to work well for me.


40 was just a little too much for me, I travel mostly on bad Midwestern roads. I run mine at 38 and am happy there. No street car needs Nitrogen.


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## XtremeRevolution (Jan 19, 2012)

JCarlson said:


> How would you pull a vacuum on a tire? I have a multitude of fittings at home and work. And it is possible to pull too deep of a vacuum on the tire and actually damage anything?
> 
> 
> Sent from AutoGuide.com Free App


You can only pull so much off before you separate the wheel from the tire. However, that's the only way to get a higher ratio of nitrogen. That is, unless you kept filling and emptying the tire repeatedly. 

To answer the thread question though, j run 51PSI in my tires. I use a work compressor that I drain on a nearly daily basis. 

Sent from mobile.


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## JCarlson (Jun 11, 2013)

XtremeRevolution said:


> You can only pull so much off before you separate the wheel from the tire. However, that's the only way to get a higher ratio of nitrogen. That is, unless you kept filling and emptying the tire repeatedly.
> 
> To answer the thread question though, j run 51PSI in my tires. I use a work compressor that I drain on a nearly daily basis.
> 
> Sent from mobile.


51 psi cold? Or max after warming? Debating filling to 51 Friday morning when it's 30 degrees out after an even colder night


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## XtremeRevolution (Jan 19, 2012)

JCarlson said:


> 51 psi cold? Or max after warming? Debating filling to 51 Friday morning when it's 30 degrees out after an even colder night
> 
> 
> Sent from AutoGuide.com Free App


Cold. Tires should always be filled cold. 

Sent from mobile.


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## JCarlson (Jun 11, 2013)

XtremeRevolution said:


> Cold. Tires should always be filled cold.
> 
> Sent from mobile.


That's what I thought. I just wanted to make sure since 51 is the "max" pressure. And considering I had a '92 cavalier as my first car before the cruze I never her really worried about anything like that for it 


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## XtremeRevolution (Jan 19, 2012)

JCarlson said:


> That's what I thought. I just wanted to make sure since 51 is the "max" pressure. And considering I had a '92 cavalier as my first car before the cruze I never her really worried about anything like that for it
> 
> 
> Sent from AutoGuide.com Free App


There is quite a bit of margin for safety on tire pressures. Actual burst pressure exceeds 200PSI. Its really mostly a matter of how stiff a ride you can tolerate.

Sent from mobile.


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## JCarlson (Jun 11, 2013)

XtremeRevolution said:


> There is quite a bit of margin for safety on tire pressures. Actual burst pressure exceeds 200PSI. Its really mostly a matter of how stiff a ride you can tolerate.
> 
> Sent from mobile.


Yeah. My boss at work was saying the burst pressure is insanely high. He actually took a driving/racing course in Connecticut I think that basically taught him everything about driving cars and handling and safety. Pretty much any car can beat out any car if the driver is good enough. They trained on dodge neons and I'm pretty sure they beat out some mustangs for their training


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## nike12000 (Sep 13, 2013)

obermd said:


> Yes. This question comes up over and over. Basically, air is already 78% nitrogen and unless you have a serious need for it (aircraft tires, race cars, etc.) there is no real difference between nitrogen and air. Both gasses expand and contract with regards to temperature so there is no benefit here either. Where _pure_ nitrogen has an advantage is that there is no water vapor in it. Water vapor can lead to corrosion inside the tire, both to the rubber and the wheel. The corrosion on the wheel from water is minimal and the rubber compound in the modern tires is designed to resist environmental deterioration for at least 4 years. Note that I said _"pure"_. The only way to get a pure nitrogen fill is to mount and fill the tire in a vacuum chamber. I seriously doubt your dealership has a vacuum chamber for this purpose.
> 
> As to the max sidewall pressure, all the ECO trims, which includes the Cruze CTD, have Goodyear FuelMax Assurance tires put on them at Lordstown. The max sidewall pressure is 51 PSI cold. Run your tires as close to this pressure as you can tolerate and you will benefit from better fuel economy and handling. The downside is the ride gets stiffer. Car manufacturers select the door placard pressure based on comfort, safety, and performance. Comfort comes first. Safety and Performance go hand in hand - a better performing tire makes the car safer to drive by improving handling predictability. Modern radial tires will not excessively wear in the center when run at the max sidewall PSI as long as you rotate and balance them on a routine basis. Tires can also handle far higher pressures than the sidewall maximum so don't worry about blowouts due to over pressure.


Most dealers don't have a chamber but I know the Ford dealer I worked at we mounted and balanced then would draw a vacuum on the tire, assuming the tire rim combo sealed well enough to do it then would re inflate with nitrogen. Similarly to vac and filling ac

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## Mikeske (Jun 19, 2012)

I am running my tires at 42 PSI and if I went higher the lousy roads out here would make for a very jarring ride.


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## HawgFan (Sep 29, 2013)

41PSI for me. It seems to a good balance between fuel economy and comfort of the ride.


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## mc2crazy (Oct 25, 2013)

Luigi said:


> I have been running mine at 46 psi. They can get up to 50 when in the heat and on the highway. I had them at stock for a 500 mile trip then pumped up to 46 on the return trip. Gained about 3-4% gas mileage and the handling is better.


Did you notice any difference in ride quality (comfort), handling and/or noise?


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## DLORESKI (Apr 9, 2012)

Well, I took mine from 33 to 42.
Our roads here aren't terrible, but also not great. So far I don't feel any difference in the ride quality.


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## obermd (Mar 3, 2012)

At 45 PSI my ECO's ride is a little stiffer, but the overall handling is better. At 35 PSI (door placard) the car simply doesn't track nearly as well when during moderate cornering. At 45 PSI it tracks exactly where I steer. This translates into slightly better fuel economy because I don't have to slow down as much to make right and left hand turns.


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## jblackburn (Apr 14, 2012)




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## Luigi (Jun 16, 2013)

mc2crazy said:


> Did you notice any difference in ride quality (comfort), handling and/or noise?


Honestly I didn't notice any difference in noise or comfort. Handling is a bit better though. 

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## diesel (Jun 8, 2013)

I think I might bump mine up to like 42 in the front and maybe 40 in the rear.


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