236 miles per hour (381 kilometers per hour): Porsche 9ff GTurbo850
Yet another tuned Porsche kicks passes on the autobahn. Ho hum. This one is tuned by a company called 9ff. The car started its life as a mere Porsche 997 Turbo (that's a recent 911 incarnation, in case you weren't sure). Then 9ff got their hands on it and upped the horsepower to 850. Yikes.
The 9ff GTurbo850 goes so fast, it doesn't need spaces in its name. It also managed this record-setting time during daylight hours in 2010, with other cars on the road. It's the fastest time in 72 years, and the top two record holders had a couple of advantages. It's hard to believe advantages over a tuned Porsche are possible, but you'll see what I mean.