Sunday, June 01, 2008

Passing gas

What with the cost of gasoline these days, we can expect a renewed outbreak of gimmicks, scams and slinky salesmanship designed to relieve the panicked and gullible of some extra cash. Since I began reading car magazines and accessory catalogs as a kid in the 1950's there have always been gadgets: magnets you clamp on your fuel line, resistors to put in series with the ignition cables, little pills that go in the gas tank, things you put in the air intake, little propellers that fit under a carburettor (remember those?) and all kinds of additives. None of them ever worked at all. They still don't.

More recently tire shops have begun to sell the idea that filling your tires with pure Nitrogen for about ten bucks a tire will increase your gas mileage. They have arguments like the one that says they will stay up to pressure longer than the 80% nitrogen, oxygen and carbon dioxide you breathe for free, and your tires will last longer. Humbug. Yes, it will prevent the inside of your tires from oxidizing, but that's isn't a problem in the first place. It will slightly slow air loss from the tires, but if you check them once a month -- as you should do anyway -- you don't have a problem in need of solving. Will you live long enough, considering the $40 and monthly refills to see any benefit? Medical science isn't promising immortality any time soon.

Sales of new SUV's are off and resale prices are down significantly. Common wisdom has it that what we really need is tiny cars with tiny engines screaming their lungs out to produce enough acceleration so that Mom's megatruck won't run you over, but is that the answer? Not always. My wife's little PT Cruiser, for instance, doesn't get the highway mileage of my Corvette and is about equal around town. In fact the 400 hp car is relatively equal to a Hyundae Sonata in the mileage department because it's made of lightweight composites and has a 6 speed transmission -- and that brings me to my point: learn to drive a manual transmission and you'll save a lot more gas than you will with any of the things that bolt on or pour in your ride, and your slow car will be a little bit faster too.

That shoebox look may be a real sexy thing if you're 16 and have a bone through your nose, but shoebox aerodynamics cost you money and that $300 wing you bought from J.C. Whitney is only going to make it worse. If you drive at any speed, aerodynamics matter -- a lot. If you don't need all wheel drive, don't buy it. It adds a lot of weight and reduces mechanical efficiency.

But hey -- you just had to have that Escalade didn't you?


Georg said...

Bonjour Cpt. Fogg,

When I had my first car in the seventies I, too, bought those gimmicks you mentioned. One even exploded in the motor compartment.

Here in Europe most cars have manual transmissions but an automatic one is always proposed as an option. Thus I know the difference in mileage exists, but it is small. Les than 1 liter per 100 kilometer.

When I am going downhill I frequently put the transmission into neutral: that improves the mileage enormously though forbidden. However, with the barrel at 130 Dollar it could become mandatory next year. Who knows.


RR said...

Are manual transmissions really more fuel-efficient than modern automatics?

I haven't looked into this in years, but the gap was almost closed last time I checked.

Capt. Fogg said...

You could be right -- newer automatics are much better and have lock up features to improve mileage, but I customarily get much more than what the sticker shows and I've always attributed it to the 6 speed. From what I read the difference is nearly 1 mpg for most drivers, but I could easily be wrong.

I'm fairly sure that the Autos weigh considerably more though and the manual is good for a couple tenths in the quarter mile.