Fall is upon us, and for most of the country that means dropping temperatures. The air - or even nitrogen for some of you Sam's Club geeks - in your tires shrinks as it gets colder outside.

As morning temps dip lower and lower, checking your tires weekly before setting off, which of course you always do, might result in their pressure dropping week by week. Don't worry - if the change is small, you don't have a leak. Rather, as the air in your tires gets colder along with the weather as fall progresses, its volume decreases. This results in it taking less space in your tire, ergo a drop in tire pressure on the gauge. For every 10 degree drop in temperature, tire pressures drop roughly 1-2 psi (depending upon tire size and overall volume of air inside). Because of this same phenomenon, always check tire pressure in the morning before the tire has heated up from driving duty.

Did you know there's an organization called the Rubber Manufacturers Association (RMA)? Well there is, and they urge drivers to check their pressures at least once a month for reasons that include both safety and economy. We'd recommend doing it weekly. Even if your pressures are spot-on week after week, it's a good way to commune with your machine and it builds character to get the hands dirty from time to time. RMA claims that 85 percent of American drivers "do not know how to check their tire pressures correctly." We hope you're not that clueless, but if so it's your little secret, and you can visit betiresmart.org to get with the program.

If your tires are low on pressure, you'll end up sucking down extra gasoline just to keep your ride moving down the highway. Not to mention, you'll be creating intense friction, which results in heat, which can ultimately result in nasty things like tread separation. As we all remember too well from the Ford/Firestone fiasco, tread separation is no trifling matter.

Quick note for you more-is-better types: overinflation ain't so hot, either. While you may eke out a little more mpg riding on rock-hard rubber pumped up to max specs, you'll wear bald spots in the center of the tread as my grandfather, the King Of Overdoing It, found out with his '80s Chevy Suburban diesel (this from the same man who brushed his teeth so aggressively with a "firm" toothbrush that he landed himself a mouthful of root canals).

So get out your quarters and try to find a gas station with an operable air pump that hasn't been run over by late night drunkards or fallen hopelessly out of service by stressed station owners. Or do what my ultra-organized father does: buy an air pump that plugs into the cigarette lighter auxiliary power outlet in your vehicle. He swears by the mini-compressor that I hear rattling away in his garage from time to time.--Colin Mathews

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Marking the tenth anniversary of adorable (if slow) little smart cars roaming the streets, Daimler AG has teamed with NASA and equipped the fortwo with solid rocket boosters enabling the vehicle to launch into space and orbit the earth. A moon landing is planned for 2011.

In another zinger, Dr. Dieter Zetsche, President and CEO of Daimler AG, proudly announced, "we invented the car - and we will do it again!"

But in all seriousness, smart is gearing up to produce an all-electric fortwo model, the fortwo ed, that will be beta-tested in Berlin, and will be part of the program known as "e-mobility Berlin." While all-electric smart fortwos have been on the road since 2007, when the brand leased 100 of them to Londoners, the fortwo ed will make use of the ultra-efficient lithium-ion battery, and that is the big news here from smart at the Paris Auto Show.

Automakers are still perfecting the operating characteristics of the lithium-ion battery, so this smart stands as a concept for now. But the promise of a high-range, zero-emissions city runabout with a cult following like the smart has enjoyed since 1998 (over one million on the road in a total of 37 countries) makes a lot of sense for European cities, where fuel costs are outrageous and congestion is a serious issue. Daimler AG promises test versions in Berlin at the end of 2009.

e-mobility Berlin is a consortium of the German government, the state of Berlin, and energy provider RWE. Daimler AG is stepping in to provide 100 smart ed vehicles, and RWE will be providing 500 charging stations. With all four entities working together, the group represents the largest electric vehicle program of its kind, and they all plan to work out the kinks of an electric-only infrastructure, the issues presented by charging, and the challenges of bringing reliable and safe lithium-ion technology to the mass market.

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We already told you about the Kia Soul Hybrid's "transparent acrylic bonnet and floor," all the better to show off its gas/electric propulsion system and battery packs. But the official view from Paris also shows a panoramic powered folding fabric roof, a rare-but-cool feature seen on the likes of the BMW 318 ti and 1963 Volkswagen Beetle (where it was fabric but manually operated).

We also told you about the high-torque permanent magnet electric motor that fortifies the Gamma 1.6-liter gasoline four to the tune of an extra 77 lb-ft and 20 horsepower, and routes that addional urge to the Soul's wheels via a Kia-developed CVT.

Just like many other gas/electric hybrids (Kia being the king of imitation), the electric motor is mounted between the flywheel and the transmission, where it acts as starter motor and assistant for acceleration and hill-climbing. This electric ally also shuts off during high speed cruising and employs regenerative braking to recharge the "Li-Poly 180 volt, 5.3 Ah power pack" located in the floor of the Soul's trunk (the very bottom of its Soul?).

Kia claims economy ratings of 48 mpg U.S., putting it in a virtual dead heat with Audi's A4 TDI concept e (48.95). Kia's claim that its Soul Hybrid "will accelerate briskly" from zero to 62 mph in 12.3 seconds reveals that this will be a poky little beast, and will eat the dust of both the Toyota Prius and the aforementioned Audi (10.4 and 10.7 seconds to 60 mph, respectively). Kia says top speed will be 97 mph. The Audi tops out at 128 mph, and we've heard reports of the Prius hitting 106 mph. Autobahn drivers, take note.--Colin Mathews

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If you're among the drivers in this country with a spare vehicle or two (or 13 in the case of one current Presidential candidate), we'd like to know what your vehicular sidekick says about you, and what you use it for. No, not necessarily a Suzuki Sidekick...though fond memories of lugging around with a high school friend in that little capable-if-underpowered trucklet make me think it might now be a great way to take in fall colors and do some light off-roading and stream crossing.

Even if you don't have a second vehicle at present (presumably many have abandoned their gas guzzlers, or even, sadly, sold their prized wheels to pay the mortgage), what would be your dream off-duty set of wheels? An old-school American muscle car in which to revel in gloriously irresponsible behavior like smoky burnouts and 6mpg? An exotic Italian beast to polish, tune, and tow to Concours? An old rough-and-tumble truck to blast through hill-and-dale, or throw wood, nails and construction projects into without worrying about scratches and dings?

Personally, being an eco-friendly car communist and rabid diesel enthusiast, I pine for the microscopic VW Lupo diesel, which is able to squeeze somewhere near 70 mpg from its torquey, ultra-efficient little turbodiesel mill. Of course (sigh), we can't buy this car in America. Okay, fine, fine, I'll take a 1970 Chevrolet Chevelle Malibu SS 396, please. Metallic blue with white racing stripes. Even though I could only afford to drive it about five miles per week, they'd be five fun-as-hell miles filled with lusty exhaust rumble and neck-snapping torque. And the intoxicating aroma of unburned gasoline wafting from dual four-barrel carbs.

Car magazines are notorious for having grocery-getter grunt vehicles that are subservient beasts to the fine, blinged-out press vehicles rolling in and out of the stable every week. Like Dan Quayle was to George Bush I, these workhorses aren't expected to shine, or impress, or even operate with much polish. But their status below the shining stars was important, as was their ability to transport the grub and grease that the pretty boys didn't want to get their hands messy with.

At Motor Trend, we had a few ignominious "project vehicles," which were automaker's science fair project cars, or tired-out press vehicles driven to within an inch of their useful lives by rabid auto journalists. Inevitably, in some random PR gesture in an attempt for favorable mentions in the magazine, a company would offload one of these beasts and it would end up lurking down on G3, three levels below the street at Motor Trend's headquarters off Wilshire Blvd. in Los Angeles.

One such project vehicle came to be known as Bucky. Bucky was a proud Ford Bronco II painted flat black, festooned with a fake hood scoop, mag wheels, and mileage unknown on a broken odometer. The lowest schlep on the totem pole at Motor Trend (yours truly in 2001) got the opportunity to drive Bucky everyday. Despite a sputtering, wheezing V-6 that needing coaxing and lots of tired winding of the starter motor to fire up, the lightweight, simple design of the Jeep-like Bronco II quickly endeared me to my funky little daily driver. Whether ferrying editors to the airport, running errands for the office, or running to press vehicle pools with other car schleppers to pick up test vehicles, Bucky's short wheelbase allowed it to turn on a dime, its notchy stickshift was involving and fun in a day where cars nearly drive themselves, and you could throw any manner of dirty, muddy, smelly equipment and supplies in the back of this support vehicle on road trips without giving a care. Heck, just keeping the ancient Twin-I-Beam front suspension going in a straight line provided plenty of entertainment. I actually lamented the close of my days as Bucky's pilot when I was promoted up into the ranks that got to drive slick, predictable leather-lined sedans and overwrought, thirsty SUVs.

So, again, any second or third cars lurking in your driveway, shop, or basement? You know, wood-panelled Country Squires, half-assembled MG project cars, slick exotic beasts, or newly-completed frame-off restorations (lucky bastard)? Tell us about it, and let us know why you keep it on hand as your second-car-in-command.--Colin Mathews

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Showing just how in touch the church is with Americans these days, RV chassis maker Spartan Motors and Bible publisher Zondervan have teamed up on a coast-to-coast RV tour of America that will hit 44 states of the union. Their mission: "To handwrite and publish a new Bible one person, one verse at a time."

Efficiency, it would seem, will not be a commandment in this new Bible.

Zondervan is the world's leading Bible publisher, and this five-month, 90-city tour is being launched, they say, "to commemorate the 30th anniversary of the New International Version (NIV) translation, the best-selling and most trusted translation of the Bible."

Spartan Motors is generously donating one of its "test RV units," the 500-horsepower, 42-foot Fleetwood American Eagle motor home (not shown here--that's a teensy RV photo we had in hand), underpinned with their Spartan K2 chassis, for the 15,000-mile tour. Clearly, God put petroleum on this earth to burn while spreading--and writing--the word. So drill, baby, drill--they'll need a few extra gallons for this venture.

We ask, what will Zondervan and Spartan do about high fuel prices and lines (GA, NC) at the gas pump? Faith might not be energy enough for their journey in those areas, but it might help while waiting more than an hour for $4-plus-per-gallon gas.--Colin Mathews