Should we refer to the door sticker or the tires themselves for recommended PSI? If the door sticker, why? I would imagine the tires would “know” best.
The tires know what’s safe in terms of how much pressure they can safely hold without blowing out or breaking a belt. Never exceed the maximum pressure printed on the tire.
The manufacturer recommendation is supposedly a careful balance of handling, noise, and ride quality, but I suspect it’s largely inertia on non-performance cars these days. Feel free to mess with this as long as you stay under the tire’s rated pressure.
Too little pressure is obviously bad as well.
Maybe they’re an undercover cop and finds the consistency comforting?
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Ya my grandad used to have a crown vic in the 80s, it’s funny. I suppose most minorities, due to regular police harassment and surveillance can tell your ironic appropriation of a crown vic from the real thing, but I’d just sorta think it a little rude to cruise around LA in a car that represents state oppression. Now, if you raised it and put rims on I’d be like… siiiick 
Well, where I’m from, you’re more likely to see an undercover cop in a Vauxhall Astra of questionable vintage (unless it’s motorway cops, they have unmarked BMWs). Any Vicky/Marauder driven by me would hardly look ‘undercover’.
Yeah, I hear that a lot these days, but I refuse to do it. It doesn’t actually rain here in Southern California anymore (last week was such a jaw-dropping anomaly–wettest July since 1886!–that we didn’t actually drive in it, just stood around and gawped), so I don’t worry about wet-weather skidding. When the tires are balding, however, I’ll keep the better ones up front, thankyouverymuch. I’ve had blowouts up front and in the rear, in both FWD and RWD cars, and I always prefer to blow a rear tire than a front one.
I also don’t let my tires get that bad anymore. But since the front wheels do the steering and most of the braking (and are the drive wheels on most of my cars these days), I give them the nicer shoes. The back ones just hold up the ass end of the car.
You folks who have to deal with spinouts and wet weather and snow and all that crap will have varying mileage, no doubt.
Well, I’m another guy who kinda resents being insulted when someone’s trying to sell me something. I don’t, in fact, inflate my tires wrong. I’m the rare person who actually makes sure the tires are cold when he checks the pressure. I kinda wish the article had mentioned how measuring the tire pressure immediately after driving as little as a mile can result in underinflated tires. I might have been interested in a pump like this, but I’m damned if I’m going to take the word of someone who starts off assuming I’m a dipshit who doesn’t know how to maintain my car.
This is a bad trend in headlines and it needs to stop. I kinda blame L.V. Anderson at Slate for perpetuating it with her “You’re Doing It Wrong” columns about cooking, but I can’t get too het up about her because generally I am cooking things wrong.
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I got an electric pump for my car, but even with the minor hassle of unrolling the cord and plugging it in to the car, moving the cord etc when shifting the pump to the other side of the car, coiling it all again to put away etc, I eventually found it was simply easier to just slap the stand-up bicycle pump on each wheel and hand-pump (about a dozen each tire). If you’re disabled then an electric pump may be very helpful, but otherwise I found them more hassle to use than a manual pump.
Now the only thing the electric pump ever gets used for is inflating an inflatable mattress once every few years.
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Sometimes you cannot really choose the time/temperature. Wouldn’t it be more practical to have an equation or a nomogram to compensate for temperature? Perhaps integrate a contactless thermometer to the pressure checker - aim at the tire, let it recalculate the internal pressure for standard temperature?
That’d be ideal. Since gas stations never have anything better than an old brass nozzle with a notoriously inaccurate pressure gauge, it’s mostly incumbent on us to carry our own tire gauge, but since I don’t really have the head for calculating the specific volume and temperature and pressure differentials from day to day, what I really ought to do is fill up my tires cold with a known good gauge on a good baseline day (maybe 75 degrees) at my normal filling station (or at least one near my most-usual driving altitude), then drive a couple miles and re-measure my tire pressure to know what the goal should be when I want to correct the tire pressure immediately after driving.
You don’t have to calculate the stuff every time. Get a computer-generated curve (or two or more if you have more pressures to track) of desired pressure vs temperature, print, laminate (whether by using a “real” laminating foil or by spray-painting the paper with clear plastic-like conformal-coating paint), attach to the back side of the gauge. Old tricks from the Age of Sliderules don’t get really old even in the Age of Smartphones.
I’m just not in possession of a NHRA-style temperature gun with which to measure accurately my tire temperature. I figure once I make my measurement once cold (having topped off as close as I can get), and again hot (that is, after driving a mile or so), I’ll have my close-enough-for-day-to-day-purposes target pressure for whenever I roll into a gas station. At least I’ll be closer than I would be if I filled up to my cold-rated pressure with a hot tire.
I did that on my old 1994 Toyota pickup and got excellent gas mileage and tire life. Haven’t done it since because I no longer own an air compressor, nor have time to park at the gas station long enough for the tires to return to ambient temperature.
You may get something cheaper. This may do the job.
http://www.dx.com/p/mini-1-3-lcd-digital-infrared-thermometer-with-led-white-light-50-260-c-2-aaa-41473
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To some extant, it has to to with the weight resting on the tires…A heavier car will press down more on the tires and for a given PSI will expand the contact area and “flatten” them somewhat. This can lead to more wear, just as if the tires were underinflated, because the sidewalls have to “bend” more. So a heavier vehicle (or one with a greater load) should have the tires inflated to a higher pressure than a lighter car with the same tires. Conversely, overinflating the tires reduces the contact area with the road slightly and makes skidding somewhat more likely. The rated inflation on the door is calculated for the anticipated weight. So if you drive mostly empty, the actual optimum might be lower than for a heavily loaded vacation.
I did at one point have a set of tires on my van that were not rated to take the pressure recommended on the door jam…
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This. The ‘trend towards pay for air’ thing is irrelevant. in CA just walk over to the attendant and ask them to turn the air on. Given that they’re not paying a lot of attention to who has and hasn’t just bought gas, they’ll usually do it without question even if you haven’t bought gas.
The sub-$40 HV-35 from Q industries is also pretty good; we have two. The rate of inflation on these new generation pumps is substantially better than on older pumps, it only takes a few seconds to bring a tire from 25 to 30psi.
We bought one specifically for use in California, despite the fact that if you can find an air pump that is not out of order at a gas station where the attendants aren’t otherwised engaged you can get them to amble slowly over and unlock the pump for your free use.
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Are you a cop? 'cuz you have to tell me if you are…
But that math doesn’t make sense. 12242 miles at 22.3 mpg is about 550 gallons. 144 extra gallons is an extra 26% of the 550. At 1% / 2 psi, to suffer a 26% loss in fuel economy would require under-inflation by 54 psi on a tire that only inflates to 35. I somehow don’t believe that the average tire in the Carnegie Mellon parking garage is negative 19 psi.
If those values are correct, 20% under-inflation from 35 psi is only 3.5% fuel economy loss, and so an average of only 19 extra gallons, not 144.
In any case, that has nothing to do with your car. Do you drive exactly the average 12242 miles in a year? Do you get exactly the average 22.3 mpg? Do you actually drive around with your tires under-inflated by exactly the average 20% found in a Carnegie Mellon parking garage, every single day, even the day after the old timey greaser changes your oil? Of course not.
You are obviously happy with your shiny new toy. That’s great. But even putting aside the problems with the calculations, the article presupposes a problem you haven’t demonstrated actually exists, and presupposes that your shiny new toy is the only possible solution to that problem. Why do you believe that your tires were chronically under-inflated? Why can’t you just buy a halfway decent pressure gauge, keep it in your glove box, and check your air pressure every time you fill up with gas? Why should we consider fuel economy advice from a person driving a 2008 Crown Victoria in LA?
I’m glad you like your shiny toy. My tires are fine.
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Hi random pseudonym!
Welcome to BBS! You should probably understand that some folks here have a hard time establishing trust, especially with anonymous accounts that show up with no fanfare and publish a few reviews in a short period of time that read like millenial ad copy. I hope you understand this suspicion, especially given the occasional opaque posts that truly are advertisements or simply attempts to increase other funding streams.
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Whaaaaaat? I live in CA, and literally today I got change at the gas station for the $1 in quarters I needed to put air in my tires… while the car was being pumped with gas!
(Shakes fist at California)
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Reminds me of that dystopian scifi trope of selling air…
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