• While going downhill, does it consume more fuel to coast on neutral or in gear? As it turns out, the car consumes almost no fuel when coasting in gear! When you coast in neutral, you consume as much fuel as an idling car, that is about 1 Gallon per hour. Surprised? Don’t take my word for it, refer to the source: Popular Mechanics. This applies to all fuel injected cars because when the accelerator is not depressed, the engine maintains minimal idling engine RPM (which is about 1000) or more. While coasting downhill in gear, if the transmission can provide at least 1K or so RPM to the engine (via gravity), then the fuel injector pretty much shuts off consuming zero fuel. However, when you are coasting in neutral, the transmission is not connected to the engine. So the fuel injector is forced to use idle running engine with fuel like it was stationary.
• Is it more fuel efficient to use air conditioner or to drive without it? Unfortunately, there is no simple answer to this one. The most concise answer is that if the car interior is too hot, then first let it cool down the old fashioned way by rolling the windows down even before you start the car [source: ezinearticles]. Next, if you are driving in the city, then you are better off will windows rolled down and A/C off [sources: carjunky, bankrate]  . However, if you are driving over 45mph, then the drag created by open windows increases to the extent that you are probably better off rolling them up and turning your A/C on [source: wikihow]. The exact numbers on this aren’t very clear. It depends on how aerodynamic the car is, how old the engine and the A/C compressor are, and so on. Apparently, for newer cars, the fuel consumed by the A/C compressor is negligible [source: edmunds, AASA].
• Speaking of the summer and car A/C, do you have any idea how hot in gets in Qatar? Hot enough to bake cookies in the car! I am not kidding: check out this blogpost by Sybil Knox. She used her car as an oven to bake cookies. She even has the recipe for anyone interested.
• Oh, and would you like to be able to start your car from anywhere (where there’s a cell phone signal)? There’s an app for that (available for iPhone, Android, and Blackberry)!
• Remember the flying car from the movie Chitty Chitty Bang Bang? This one:
  

  Flying car from "Chitty Chitty Bang Bang: The Magical Car". Source: http://www.badmouth.net/top-five-flying-cars/

  Well, it’s now a reality.. well almost. Terrafugia has come out with Transition that has been cleared by FAA. But it looks a little different. Like this:

  

  Terrafugia Transition: Flying Car

  For more information on the story behind the car and the technical challenges in designing the car, check out this article in Boing Boing.

  Check out this link for a brief history of  attempts at flying cars shown as a slideshow in Popular Mechanics.

• Moving on, looks like the future cars are going be a lot more audacious than your stereotypical backseat driver. They are being designed to spray vitamins on your face and tell you how to drive, constantly! Don’t believe me? Check out this PopSci article then. Nissan really is building such a car.

I will end this post with a link to the Huff. Post slideshow of the finalists for the Progressive Automotive X Prize. Enjoy!

I started from Denton early in the afternoon towards College Station. After a long dry spell, it has been raining since noon. I knew that the roads would be wet and my Mustang would have less traction than usual. So I started cautiously. By about 3PM I was past the city of Dallas on I-35E South and was about to merge into I-35 South. Thanks to construction around there, there were 2-feet concrete separators along the sides of the highway.

As I was approaching the merge point I saw a state trooper with his lights on. I figured someone has just gotten a ticket for speeding, but didn’t think much of it. I was driving at 60 miles/hr, at the speed limit. This was t-6 seconds before the accident. As soon as I merge into I-35 I see a car about a 100 ft in front of me going at about 20 miles/hr with no flashers. It was about a third of a second before I realized that the car was going too slow for a freeway (the suggested minimum is about 40 miles/hr. Anything less than that it is advised to have your flashers on to warn the traffic behind you). So I begin to slow down immediately. I stamp on my breaks and downshift from 5th gear to 3rd gear and am slowing down quite quickly.

It is now t-4 seconds to impact and I realize that I am going to have to slam on the breaks real hard to avoid rear ending the car in front of me and I not sure if I should do it. Its been raining, the roads are slippery, and I could lose control of the car breaking that hard. So I look in my rear view mirror to see if the left lane is open. All I see is the state trooper driving by at about 50-60 miles/hr, and I gauge that he should pass me in about a second or so. Meanwhile I am still closing in on the car in front of me. I best I have managed so far is 30 miles/hr, and I am still gaining on the car in front.

It is now t-3 seconds to impact and the state trooper has just passed me. So I shift to the left lane and breathe a sigh of relief. But I quickly realize that there is traffic about 200 ft behind me closing on me fast. I have to accelerate and quickly. But I am doing 25 miles/hr and am on 3rd gear, so there is no way I can accelerate fast enough in 3rd. So I downshift to second gear for higher torque and acceleration. Its a 3.8L 225 HP V-6 engine, it can pack a punch in lower gears.

It is now t-2 seconds to impact and I have just downshifted to second gear. As expected the car slows down with a jerk, but what I do not realize that when the car slows down like that (due to resistance from the lower gear in the transmission), the wheels move slower but the body of the car is still plowing forward. This means my heavy engine is pressing harder in the front and my front wheels are hugging the road whereas my rear wheels have lightened up significantly. If I wait for a second, the load will stabilize. But I completely miss that and I am in a hurry to accelerate to avoid the traffic behind me. That is when I make a critical error.

It is still t-2 seconds and as soon as I downshift to second gear I hit the throttle (gas pedal, or accelerator pedal). The front wheels are still hugging the ground the rear wheels are still light. Thanks to the rain after a long hot dry spell, all the oil in the road have floated to the top and the traction is low. So as soon as my engine responds with a roar the rear wheel starts spinning but can’t grip the road. I realize that immediately because my dashboard shows that my engine rpm has rocketed up to 4000 while my speed is still at 25 mile/hr. I knew I was in trouble. In the next fraction of a second the rear wheel will grip the road and the wet road is going to make things very very difficult for me.

It is t-1.5 seconds and the rear wheels hit the ground and my Mustang’s rear started skidding to the right. I tried compensating for it by turning right (in the direction of the skidding). My front wheels did not respond immediately, and when they did, I had turned for too long and the rear started skidding to the left, and I tried compensating for it, again, by turning left (in the direction of the skidding). The same thing happened again, I had over-steered, and my car started fish-tailing back and forth.

It is t-1 seconds to impact. At this point I knew it was useless. The wet road provided absolutely no resistance and the fish-tailing was getting wilder and wilder until my car turned 90 degrees to the roads and crashed into the concrete separator at over 35 miles/hr. There was thud, the airbags deployed, and all that  was left of my car was this!

Mustang - Front View - Totaled much?

Mustang - Side View - Airbags deployed