I’m guessing this air pump was effectively free when you factor in the money they paid you for this advertising.
Also; you can buy a little pancake air compressor for not much more money than this and use it to power all kinds of wonderful tools. Not going to carry it around in your trunk, but I use mine all the time and only occasionally on car tires.
You can also top off tires with your basic bike floor pump. Takes a few pumps, but at 30psi, it’s not a lot of resistance.
Exactly. If a car tire is completely flat, a bike pump will take a while to inflate it, but if you are just increasing from 30 psi up to 35 psi, or whatever, you can do that fairly quickly with a bike pump. And a lot of people already have a bike pump.
Hi,
Thanks for the reply! I actually only review products I purchase for myself, for my own needs with my own cash.
Also, I agree pancake pump is a good one too, but a different use fit than this tire pump. If I find I have wider needs that my tires, maybe I’ll pick up a pancake one too.
Thanks again!
-rjcjr
This is not accurate. We would label anything “paid for” as advertising. This is a clean review.
Maybe I’m missing something, but how are we inflating our tires “wrong”? The recommendation of this article is to simply inflate them “at all”.
I’ll also say that I have a different model of Viair, and it’s great. Inflates tires super fast, and way better than the cheapo plastic one I used to have (which broke when I tried to get my spare up to the recommended 60 psi).
I’m probably missing something here, but how are you coming up with the $430/annually number?
I looked at the excel download and the worst case it has (-15psi) is just $59.40/annually for a 4 door sedan.
The problem is that the gauge on many pumps can be off by a pound or more…I’ve been through a lot of portable air pumps
You might look at investing in a good gauge.
I have a Longacre gauge that I spent $30 on a couple of years ago–accurate to 1/4 pound.
You have to consider the range of the gauge.
They are most accurate at the middle of their range. If you need 34 pounds, look for look for a 60 pound gauge
I’m confused.
Are you really saying that it was news to you that the recommended tire pressure is listed on a sticker or in the manual?
What pressure were you using before? Or did you just never check your tires? I guess I just thought this was common knowledge, but maybe I’m older than I thought.
Yeah, I’m missing that too. Here is I believe the original source where that’s coming from:
http://www.carnegiemellontoday.com/issues/nov-2005-issue/news-flash/#16859
And if you update it to $3/gallon instead of the $2.25, you get $432 annually. But I’m not seeing how that math works out.
They found that on average the cars tested were underinflated by 20%. If we assume the average PSI around 35, that’s 7PSI short, and at a loss of 1% per 2 PSI, that’s only a 3.5% fuel efficiency loss, which would only be like an extra 20 gallons of fuel a year.
I was thinking exactly this. If the $430/year was a 10% figure then you would be about 10 psi down on average on each tyre, which is 20 psi. Assuming you pumped them up from time to time so this is an average figure, then they would be going down to 10 psi. I don’t think the linear relationship between psi error and inefficiency would apply.
But, it gets stranger. If we have our types pumped to the optimum pressure, then we would expect some parabolic well around this minimum, so the savings should go as the square of the psi error.
My guess is there is a fuel saving in having high tyre pressures, but beyond the normal type rating, your tread will become convex, so you will have less contact with the road, the tyre will wear unevenly, and you are less able to brake and accelerate. So, this would give you a linear relationship downwards from the rated pressure.
What pressure do you have to have for a $430 saving annually. I suspect you will need a negative pressure for that.
I’m guessing that the opening paragraph answers your question:
I am a recent transplant to Los Angeles from Manhattan. Like many New Yorkers, I didn't drive a car when I lived in NYC. Now, like many Angelenos, I must. Since moving here, I have been exploring Southern California's rich car culture, and I love it. I'm an I.T. professional who spent the last 20 years without needing a vehicle. The process of becoming reacquainted with car technology has been fun, as is becoming part of a community of car geeks here.
Also, ask folks that you work with – I’m betting that a lot of them do not know about the door frame sticker (it seems to come as a revelation to many when it is pointed out).
I am pretty sure that for my driving test I had to learn that horrible things and bad mileage happen if you don’t keep your tires at the recommended pressure.
That $430/year sounds like one of those hyper-inflated numbers that’s used to sell papers.
That said, Viair makes good compressors. We use them on our robots.
It’s not just true for cars, you know. If you’ve ever gone from riding under-inflated to properly-inflated bicycle tires, you’d be surprised how much easier your bike gets to pedal. This is especially helpful with things like electric bikes where you can basically get more mileage out of a single battery charge. Good to keep it taken care of.
http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/underinflated-tires/
Its funny how few people ever think about tire pressure. My folks put their large camper (40 footish) out on the local beaches every other week for the entire summer. Kind of like the family mobile beach house. The other day sitting out there on the hottest day of the year and you’d see every third car stuck in the sand. People figure "my all wheel drive (not the same as full 4wd) cross over can totes handle this. For one thing they can’t (there’s a reason they don’t qualify for a permit to drive on the actual beach, just the sandy dune roads near the beach). But these idiots don’t even know to air down their tires. You’ll see them diging and fighting, attempting to tow each other out. Until some one with some experience comes up and says “let air out of your tires”, and boom they pop right out. Then you get to watch them have blow outs when they hit the pavement and forget to air back up. Its kind of hilarious.
These are not portable. Which is the major point of the compressor the OP is recommending. A portable compressor/electric pump whathave is probably not necessary for most people doing most regular daily driving. But in terms of any sort of off roading, beach driving its a huge convenience to a necessity. Many of the parks where you might be driving in conditions that need lower pressure don’t provide an air pump station. Those that do will have a line. If you do a lot of long distance driving, or just like to be prepared a small one can be nice to have, along with a jumper pack and assorted other tools.
There are all sorts of smaller pumps available. My dad uses one about a third the size of the one cited. Plugs into the 12v ports in his truck. He also has these little tire deflator plugs that making airing down really easy. They’re little brass plugs you calibrate them to a specific pressure, screw them onto the tire nozzles and they drop the pressure to the set pressure in a couple minutes. He even timed how long it takes so he can tell where half his beach pressure is without having to carry a separate set, because NERD. I once caught him calculating historic weather trends for different parts of Florida at different times of the year, and checking them against historic trends in travel prices. His goal was to find at least 10 days in a traditional cheap off season that have disproportionately nice weather.
A tip for Californians - state law requires that all gas stations provide air pumps and water for free if you are buying gas.
In California, if you buy gas, the station can’t charge you for air. Just ask them to turn it on. Same for water.
