So I took a drive in the Prius...

[Morris Minor]

... a rarity; my daughter drives it 98% of the time &, apart from bodywork scrapes, keeps in fairly good condition. It seemed to be riding really harshly - even for a Prius.  So checked the tire pressures. They were 41 PSI all round instead of 35 front /33 rear.

The car has pretty woeful stopping distances anyway so I don't think the oil change monkey who probably did this for her was doing any favors.

Unrelated top tip: I discovered that its air-conditioning /ventilation works a lot better when the cabin air filter is replaced for one that is not *completely* clogged.

[AutobahnSHO]

lol
Scary how most people maintain cars.



(Not that I'm much better. I have noticed Odyssey burns a lot of oil- not as much now that it's cold out.)

[280Z Turbo]

This = not a big deal

As long as you don't exceed the air pressure on the sidewall, there is no safety issue. It's pretty common to increase tire pressure at autocross events.

[JWC]

I was worried about the tire pressures on my daughter's Focus (she is on a business trip and last week one tire was down to 16psi, couldn't find a cause) and left my air compressor at her house. I bumped her tires up to 41psi for now, but she's complaining about the harsh ride, so I'll knock them back down once she has returned.

My Honda dealer bumped the PSI up on the C/T today because the TPMS warning was on with the temperature drop. I probably shouldn't mix air with the nitrogen anyway, but I'm not really feeling the love for nitrogen.

[Soup DeVille]

Air's already mixed with nitrogen. In fact, air is mostly nitrogen anyways.

[giant_mtb]

lol Nitrogen. 

"The only benefit from running pure nitrogen in tires is the increased air retention (slower loss of air out of the tires over time). A tire that is normally maintained with the proper air pressure will perform exactly like a tire with a pure nitrogen fill. If you can get a pure nitrogen fill for free, there is no harm in doing so but very little (if any) benefit from it."

http://blog.tirerack.com/blog/make-driving-fun/pure-nitrogen-in-tires-facts-and-myths-v1

[CaminoRacer]

40 psi is probably too high - I ran my tires at 40 and the rears started to wear in the middle. I've since dropped them down to 33ish.

[93JC]

lol Nitrogen. 

"The only benefit from running pure nitrogen in tires is the increased air retention (slower loss of air out of the tires over time). A tire that is normally maintained with the proper air pressure will perform exactly like a tire with a pure nitrogen fill. If you can get a pure nitrogen fill for free, there is no harm in doing so but very little (if any) benefit from it."

http://blog.tirerack.com/blog/make-driving-fun/pure-nitrogen-in-tires-facts-and-myths-v1

"The only benefit from running pure nitrogen in tires is the increased air retention (slower loss of air out of the tires over time)," is pure, unadultered buuuuuuuullshit.

[Laconian]

The less nitrogen you run, the more effective it is. Homeopathic levels are the most effective.

[JWC]

The dealership includes nitrogen service free the first year---and it comes with free tire replacement (if I pick up a nail for instance) for that period. After that, don't care anymore.

[CaminoRacer]

Running an even heavier gas would provide further air retention. I recommend Radon.

[JWC]

Running an even heavier gas would provide further air retention. I recommend Radon.

There is a 2007 conversation on this forum that recommends radon also...LOL.  There was mention that glowing tires made it easier to find the car at night in a parking lot.

Raza on the other hand just uses the blood of orphans in his tires.

[giant_mtb]

"The only benefit from running pure nitrogen in tires is the increased air retention (slower loss of air out of the tires over time)," is pure, unadultered buuuuuuuullshit.

Yeah, I've never really seen any tests or data about air retention differences. Not that I've really looked, but now that I think about it...

From The Consumer Repore:

"The test started on September 20, 2006 and the final measurements were taken on September 20, 2007.  The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely."



The test started on September 20, 2006 and the final measurements were taken on September 20, 2007.  The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely.

[Soup DeVille]

At extreme temperatures, nitrogen will act more predictably. There are no chemical reactions that can take place that will change the gas volume. No water in the air to boil. That's why nitrogen filled tires are used on airplanes.

This all means exactly jack shit on a passenger car tire.

[JWC]

At this dealership  (and I'm sure others also) this is just an add-on to pad the invoice. It wasn't a deal breaker for me because of all the other discounts to move this car off the lot...as well as leaving it had advantages such as road hazard; free rotate etc.

The Jeep dealer I used to work for added $200 to the list price for pinstripes on the Laredo editions. No customer ever thought to look at the list of Laredo standard trim items from Jeep and saw that pinstripes were part of the Laredo package.

[AutobahnSHO]

Crooked.