字幕表 動画を再生する 英語字幕をプリント The first gas-powered car sped through the streets of Mannheim, Germany at a blistering 10 mph. Today, we can go a LOT faster… so what's changed? Hey motorheads, Trace here for DNews. Over the last 130ish years, car speed has come a long way. As of February 2016, the fastest car you can buy is the Bugatti Chiron, which is limited to 261 miles per hour. (420 km/h). But why is that car faster than yours? How did we figure out how to make cars go faster? First of all, and it's probably obvious, but the major reason cars today can move so fast, is because engines have gotten a lot more powerful in the last 130 years. The 1908 Ford Model T had only 22 horsepower and a top speed of 45 miles per hour (70 km/h). But today, a base Honda Accord can easily clear 100 mph (160kp/h) with almost 200 horsepower! Modern cars can pull more power from highly refined petroleum. Today's more powerful cars, can push more mass, more easily. But it's not that car engines have gotten more efficient, the Model T only got 3 miles per gallon less than the average car today! Only 14 to 30 percent of the power from gasoline combustion is used to pull the car forward; most of the energy is lost to heat and friction. So, to give cars more horsepower engineers have either added more engine, or reduced weight… or BOTH. It all comes down to the Power to Weight ratio. That super-fast Bugatti Chiron has 1,500 horsepower, but needs TWO V8 engines to get that -- that's a lot of weight. So, to make the car go fast, they needed to make it lighter. The power to weight ratio, is a simple formula… divide Weight by Power. Lemme give you an example or three… A 1200 pound Model T, has 22 horsepower. It's weight to power ratio is 54.5 pounds for every horsepower. That's not great. A 3000 pound 2016 Prius has 121 horsepower so has a better ratio of 24.8 pounds for every 1 horsepower! While the new car does have more power in a heavier vehicle it is a balance. By comparison, the Chiron weighs in at 4,400 pounds with 1500 hp: for a ratio of 2.9. 2.9 pounds per horsepower. That. Is. Crazy. Obviously, it's way fast. If engineers can get a low weight-to-power ratio, they'll have a faster car. But to MAKE a car with a heavy engine have less weight ain't easy. Ford mixed the steel on Model Ts with the element Vanadium to try and make it lighter; engineers still do stuff like that today. The Prius uses aluminum, plastics, and special high-tensile, high-strength steels. The Chiron, however, was built with ultra-lightweight materials like titanium and carbon fiber, keeping the weight down even further and making for an even lower ratio! Of course, the Chiron is 100 times more expensive than a Prius, partly due to that lightweight material, so there's that. Tweaks like these are the reason horsepower has increased 80 percent from 1980 to 2004… but even then, we can only do so much. If you have a big engine, and a light car, you can still only make it go so fast. And the faster you go, the more air friction will start to affect top speed. For this reason, the car that holds the fastest land speed record in the world -- 763.035 mph (1227.985 km/h) -- looks NOTHING like a Chiron, or even a car. It looks like a jet, because jets are perfect for minimizing drag from air. But basically, for every pound added either more power has to be coaxed from the engine, or a bigger engine has to be built. The power-to-weight ratio is a delicate balance even for the muscliest of cars. Without understanding it, we'd never have made cars go fast. Sponsor? It also takes a lot of effort to keep your car clean. Techron by Chevron’s patented Precision Clean Technology targets and removes deposits left by lower tier gasolines. It bonds with and breaks apart carbon deposits, more effectively than other additive technologies. Techron gets into the deepest parts of the engine, where the most destructive deposits built up, and sweeps them away. No matter how fast we can make cars go, though, there will always be speed limits holding us back. How we decide speed limits isn't arbitrary to get me pulled over every other week... in fact, there's a ton of research on it! I checked! Take a pitstop and watch here. What's your favorite speedy car? I always loved the Lotus, any of them. They're so curvy! Tell me the car you had on the poster hanging in your childhood bedroom...and subscribe for more dnews, tomorrow, and the next day, and the next day…
B2 中上級 なぜあなたの車はスポーツカーよりも速くないのか? (Why Isn’t Your Car Faster Than A Sports Car?) 183 12 Jack に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語