Mileage Myths

When my dad taught me to drive, he drew out a full diagram of the engine to show me why pressing the accelerator made the car go. He also showed me how to change the oil, change a tire, check fluids, and of course test tire pressure (oh, and how to call AAA when I forgot how to change a tire). His thoroughness later helped me kick ass on a flight-school mechanical test, but at the time, the reason for teaching me all this maintenance stuff was so I could help my $800 Dodge Colt trot along until another summer's wages rolled in (alas, no Mercedes Benz for Christmas for this little pioneer girl...)

Anyway, it never occurred to me - or I was in snooze mode when he told me - that inflated tires also meant saving gas money (not to mention gas). But I did hear rumors (albeit from incredibly unreliable sources) that playing the radio and driving a dirty car lowered gas mileage. I always wondered, and at last I know, courtesy of my favorite NPR guys and yours, Tom and Ray Magliozzi of Car Talk, that those are just mileage myths. That is, unless, as Ray replied to one caller, "...you're cleaning off some enormous, mutant, three-dimensional bird dropping in the shape of airplane flaps."

-Jenifer Morgan... off to make like Icarus, minus the plunging-into-the-sea-to-my-death part...
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Another tip is to replace the air in your tires with Nitrogen. Tire stores like Big-O have a one time charge ($5/tire) but then free refills. Supposedly, the nitrogen doesn't expand/contract like regular air as the tire heats up with use, so you maintain a common pressure. Also it doesn't leak out of the stem like air so there's no need to top off on a regular basis. Race cars use nitrogen for these reasons. Happy driving.
You should not inflate your tires to the psi listed on the tire itself, but rather always to the psi listed inside your gas tank (for German cars) or in your owners manual. The same tires can be put on any car so the psi you should use depends on the car, NOT on the tires. The tire itself lists the maximum psi for the tire under any circumstance, but that might be way overinflated depending on the car the tires are on. This is what two mechanics have told me.
If I inflate my tires to the PSI listed in the owner's manual then I have tires that visibly look flat. There is a big difference between the 30 PSI listed in the owners manual and the 51 PSI rating of my tires.
Always follow the owners manual. My mother owned a Lexus ES250 (glorified Camry) a while back that had the same problem with the front tires looking low when properly inflated. Also remember that for every 10 degrees of ambiant air temperature change, you gain/lose 1 pound of pressure. So if you fill your tires to 32psi on an 80 degree day, when the weather turns brisk and it is 40 degrees, you only have 28psi in your tires. I and many other car guys (and girls) often run a few pounds more for better handling and load carrying capacity, my Saab wagon for example requires 33psi for 2 people, and 48!psi for 5 people in the car.
The PSI listed ON the tire is MAX PSI. You should inflate to the pressure listed on the sticker on the inside of the drivers side door (also listed in the owner's manual).
Don't put your quarters into the air pump at your local gas station before you know this: in many states - including California - gas stations are LEGALLY REQUIRED TO PROVIDE FREE AIR, regardless of whether you purchase fuel or not. The pumps can still be coin-operated though. So go inside the station and ask for the air to be turned on (sometimes they will give you tokens to put in instead of quarters). The more you know...
This is one of those tips that makes you stop and go, "oh, duh." Although I don't drive, I appreciated the comment about yogilates class, having hurt myself in ways that cannot be typed...lol Thanks!
I'm surprised your Bite wasn't subjected "Pump 'em Up," but perhaps it's a trademark issue. Are you not familiar with pumpemup.org?
I saw the sidebar ad yesterday saying the biter chicks were going to be on the Today show this morning, but I missed it. Overslept, too much organic wine last night. Is it floating out there somewhere on the web where I can catch it?
A link to some eco-friendly moist towlettes would go nicely with this tip. I often think to check my tires as I'm filling up my tank, but then I see all the brake dust down there and figure I'll do it later. Keeping some little hand wipes in the car would be the smart thing to do.

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