Bigger is not Better

This morning, I'm sitting on my couch watching "Motorweek" on PBS.  Yeah, I'm that cool.  This week's review: The new Honda Fit.  What separates the new Honda Fit from its past brethren? 

Yup, it's bigger.

This is a trend that has been going on for, well, ever.  The new Fit is larger than the first generation Accord.  The new Accord is bigger than, um, a small battleship.  The original Toyota Camry is smaller than today's Corolla (by a scant 0.4 in).  The Mazda MX5: bigger than the previous Miata.

External dimensions don't particularly bother me, though.  Sure, smaller cars are more fun to drive and easier to park... Big deal.

The offender is not size, but weight.  The tiny corolla is considered svelte at a mere 2700-2900 lbs (which is actually quite good).  Compare that to the even smaller Fit: 2500-2600 lbs.  A Porsche 911: 3494 lbs.  3500lbs for a sports car?  That's grown quite a bit from the original 911's 2200 lbs.  Granted, I'd rather be in the modern day Porsche in an accident--that 1960's 911 wouldn't fare too well against a Chevy Suburban.  

Why is weight a big deal?  Let's take a look at Mr. Newton's 2nd law of motion.  

"The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object."

This is more commonly simplified into the equation, Force = mass * acceleration.  There you have it.  Increase the mass, and you need more force to go.  In a car, that means less responsive steering, longer braking distances, and more gas.  

Now, naysayers will be sure to counter.  Sure, today's cars handle much, much better than their older (and lighter) counterparts... and they're faster, too.   But think how much faster, better they'd be if they weighed less...  And they'd use a lot less fuel.  

There it is.  If we want to save fuel (and reduce CO2), we need lighter vehicles.  Hybrids, electrics, diesels are all good... but we could add serious mpg by chopping off a few lbs.  

I'm not suggesting cutting out safety features (air bags, seat belts...they all add weight).  Given that, what do we do?  Make smaller cars (or at the very least, stop making them bigger).  The use of new technology (high strength steel, composites, plastics) can help, but they also may increase price.  Make more small cars.  Save money, save gas, have more fun (and still be safe).