One last word (I promise). "Cold" actually means ambient temperature. If you live in the desert where the temperature may vary from 50 at dawn to 100 at noon, you would need to reset your tire pressures several times a day to stay at Honda's recommendation. I don't think anyone here is OCD enough to bother with that. Checking regularly (weekly, and at the same time of day) is more important than the actual pressures anyone chooses to use.

 

I just adjusted my tire pressure recently to 35 PSI front and 33 PSI rear. I am getting 38 MPG at this point (actual). My TPMS triggers at 30 PSI.

 

ahh so then choosing 13lbs is OK? Sorry being facetious.

Americans are notorious for not checking their tire pressure (or oil level). Sorry, I don't have a cite for that. Any discussion that encourages either behavior is helpful. Both are critical for safety or reliability. :thumbsup:

For the record, I look disparagingly on any mods that alter the operating characteristics of the car unless it's for closed track racing. If you change the wheel/tire size then you have to experiment with tire pressure.

I run stock tire sizes on factory wheels at manufacturer recommended pressures checked weekly before the car is driven. I use the recommended grade of oil an change at the recommended intervals. I let Honda do all the designing and testing because I'm not an automotive engineer.

 

So to sum up this thread: Do whatever the hell you want, as long as when your tires fail you don't hit my fit on your way off the bridge. Even a monumental gain in MPG is not worth my neck, I don't care how much I save.

 

Just a few points of note: Granted, a tire pressure so low that you smack the rim is dangerous (before you even get to the pothole). My reference was more to the rest of the car & suspension and not necessarily just the Rim. Driving on a 45lb (cold) tire means you are going to be running on Rock hard tires which is going to pass the shock of the road right up to the chassis and into the car where a properly inflated tire would give a little bit. I've done plenty of driving in NYC and it can be really rough there. I can't imagine driving a 40psi tire or harder around there. A pressure that high also rounds the tire out a little more which means there is less of a contact patch with the road.

Agreed.

As a general note, for some reason there people that think it is ok to drive with certain components of their cars being unsafe, just because they think they should be able to. If someone has aftermarket tires/wheels and does the research to find that the pressure adjustment should be changed, then that's one thing, but running stock tires/wheels and no research is another. By the same logic it is it is ok to drive around after dusk with your lights off or during a downpour because you can still technically see. Doesn't make it safe. Also, the I've always done it this way doesn't hold true. Cars, tires, technology, and safety have changed massively over the years and to think that an old standard (like you MUST change your oil every 3k miles) is just living in the past. If I'm out driving my FIL's 69 shelby GT500, I'd use the standards from back then, but this is a 2009/10 FIT and I will treat it very differently.

~SB

 

So the bug up some behinds is the safety issue...couple points to consider-

How many accidents have been attributed to tire pressures? Either too low or too high? (I dunno - just asking)

How many passenger car tires have "exploded" because tire pressure was too high? (again, just asking)

Does tire pressure, too low or too high effect handling? (I think we could all agree on that one)

What is the greater safety issue - tire pressure or some other actual driving issue? Not paying attention, cell phone usage, putting on make-up etc...(let's put it in perspective)

I, for one, don't trust anyone of you turds on the road with me. So go away. (just kidding...LOVE YOU MAN!)

 

I'm with this guy.

 

Proper tire pressure seems statistically insignificant in affecting accident rates. The government study mandating TPMS on cars puts it around 0.8% of accidents are due to under-inflated tires (no mention of overinflated tires, but I suspect this didn't register). TPMS was a knee-jerk reaction to under-inflated Ford Explorers' tires blowing out and causing roll-overs. The system seems an unnecessary expense, but is integrated in ESC systems that are mandated on all cars in 2012. link

The insurance companies lump it in the bottom few percent of accidents along with brake failure. link

But hey, maintaining correct tire pressure is free insurance!

 

I say pump them up until they pop. and then go get some new ones

 

mrmatte..bet you would get some good mileage just before they pop. I wouldn't want to be around when they do, however! I was going to leave this thread, but I got a smart-ass private email from one of the Obey Honda as if Honda were God types. They sound like the self-appointed "experts" who were in my engineering classes. All talk, and no real experience. No initiative, imagination gain or progress. Those guys are still doing the grunt work at GM and Ford. Not designing or experimenting because they can't think outside the box. Oh well, signing off..again.

 

You got an "obey honda god" email from a GM/Ford grunt-type engineer? Tell us more...

 

No, it was from one of the smart-ass posters on the forum. One of those who think they have all the answers because they read a few magazines and the Honda owners manual. No real engineer would take the attitude they do. This thread should be closed, since it has become non-useful, and diverted from the original idea.

 

Amen!

 

My pressures have dropped under 30psi and my TPMS never triggered. Makes me wonder when it WOULD trigger. I'm such as lazy bastard too- I've gone too long without checking my pressure again. Been three weeks and I KNOW I have to do it. Such a pain in the ass- quite literally.

Dan

 

Base on Honda Service Manual, TPMS will trigger at 26 PSI. However, mine trigger at 30 PSI. I will keep it as it is.

 

Mine Triggered at about 27psi when the temp here dropped to sub zero. After about 1/4 mile of driving when leaving work one day, I hit a seam in the road with both front tires simultaneously and the light came on instantly. I'm sure it would have come on shortly thereafter but the bump seemed to trigger it. Stopped at the nearest station with Air and pressure was at 27,28,29, & 31.

~SB

 

I'm pretty anal about always having my tire pressure set to manufactures specs, but here in Texas it's very difficult. There are wild temperature fluctuations in this state, I'm talking 30 degrees +/- in the span of a day. Thus, setting the pressure correctly one day, might mean the next day it's too low or too high by 3 psi. You do know that for every 10 degrees change in temperature, tires lose or gain 1 psi depending on a temperature decrease or increase? This is very frustrating to me, so I ususally check the weather for the week and adjust my tires to be at 33 psi for the lowest temperature. Which means despite my best efforts I'm almost always driving around over-inflated. But I would rather be over-inflated than under-inflated so I deal with it.

 

In Arizona we have the same...or even greater problem with temperature fluctuations. Several psi changes during the day, and 5 or more when highway driving. It doesn't cure all of it, but I get smaller fluctuations after filling with nitrogen. Also have less pressure loss while sitting for days. Nitrogen has larger molecules, and while it still seeps through the tires, it does not do it as much as plain air does.

 

Myth

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link


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The only entities pushing nitrogen fills are tire and car dealers. The only enhancement is to their bottom line.

And quit baiting me.

 

Nitrogen isn't perfect, and I would never pay extra for it. Some dealers around here do it for free. It still leaks, but not as much as regular air does. If it's free, I use it. One dealer here charges for a first fill, with free refills for the life of the tire, and complete road hazard tire guarantee for the life of the tire. Don't know if it is worth the $39 that they charge, but that is less than Discount Tire charges for their lifetime road hazard warranty on 4 tires. On my Solstice, I do notice a lower pressure variance, and have gone 3 months without going below 32 psi. With regular air, it would go about 3 weeks before it went to 32. Not perfect, but better than before. (what's neat about the Solstice is that it gives an instant digital readout of the pressure in all 4 tires. It isn't a perfect read-out, but is accurate to within a pound or two.)

I have nothing to gain by "baiting" you. It's not that important to me.