Weight: Friend or Foe
Driving is fun and I hope you enjoy it as much as I do. Today, just about everything on the road will accelerate to 60 in under 10 seconds and reach 100 mph without breaking a sweat. But just a few decades ago, those performance numbers were supercar rare.
There’s plenty of good reason too. Modern engines make more power with less weight, suspensions are better, brakes are better and the tires are better. So even though a 60’s muscle car might beat you off the line, on a track you’d be able to out-brake and out-handle it – even surpass the top speed and it has a lot to do with weight.
It’s said in racing, you can only use 100% of your tires grip at any one time for acceleration, cornering, or braking. So if you are traveling at high speed and enter a corner without braking and are utilizing 100% of you tires’ grip, any application of brakes or more power will cause you to break traction and spin. Same holds true for hard braking and hard acceleration.
And this is where weight comes into play. If your vehicle weighs in at 6000 pounds, curb weight for a full size SUV, you are going to reach that 100% threshold easily and more often than you would if you were driving a lightweight car. That’s why SUVs have to go slowly around corners and why they need longer stopping distances… All that weight must always be taken into account.
In everyday driving though, where you are most likely to notice the weight is under acceleration. In a full size SUV, you have to really step on the gas to make a quick launch or make a pass and if you’re paying attention to your specs you’ll know that you are laying down hundreds of horsepower for some relatively mediocre performance. It’s why your city mileage is so low. Even if you have Displacement on Demand where engine cylinders are disabled at cruising speeds, you’re going to be calling them back into action any time you step on the pedal with anything more than a feather touch. Heavy cars need mad amounts of power to go.
There’s good reason to be weary of weight when it comes to safety as well. Accidents involving SUVs are nasty affairs for everyone involved. Roll-overs are a very real risk and all that mass in motion means that the risks are greater to the occupants of any other vehicle involved. If you think you’re better off being in a heavy vehicle, do a little research on your own about SUVs and fatalities. And while I have your ear, never let an inexperienced driver behind the wheel of a heavy vehicle without additional safety training. You might just save a whole bunch of lives.
Conversely, lightweight vehicles are fun to drive. It takes less power to get them going and they change speeds more readily for passing and braking. At every step of the way, you have a greater window of available traction for cornering. Even if you are not interested in spirited driving on twisty mountain roads, you will surely appreciate the difference when your spouse or young driver throws the wheel over in an attempt to miss a deer or negligent motorist. Driving mistakes happen everyday and the ability to avoid one is vastly superior to relying on a false sense of indestructibility.
But don’t take my word for it. Before you plunk down 40-60k on your next SUV purchase, go drive a BMW Mini or 3 series sedan. If you were thinking luxury SUV, you could compare against a Corvette, Porsche or even a Lotus. Believe me you will have more fun in the Lotus. If your needs will not allow you to go that small, consider something mid-size but keep an eye on the weight. And when it comes to needs, be sure to avoid the pitfall of buying the utility vehicle you only need a few times a year. There are rental companies for that.
