’O Lord won’t you buy me a Mercedes Benz,
My friends are riding Porsches and I must make amends.’
- Janis Joplin

Note:
This review resumes from Part 1 which is a

discussion of safety features in cars:
http://www.mouthshut.com/readreview/43729-1.html

3. Tyre Pressure Warning (TPW)
The high number of accidents due to blowouts on expressways in India highlight a chronic underinflation problem with tyres.
Low pressure will increase the ’contact patch’ of the tyre with the road which increases the friction (and grip).
Higher friction leads to higher temps at high sustained speeds (over 100-125 km/h).
If the tyre gets hot enough, the air pressure builds up until it bursts causing an accident or rollover.
Always overinflate your tyres when in doubt.
The recommended pressure is for ’cold’ tyres.
Most of us have the air checked when we fill petrol at the pump.
Usually the tyres have been run for over 5 min and are warmed up.
Thus their pressure reading will be higher than the actual amount which might cause the attendant to ’bleed’ some air out give you underinflation in reality.
I always fill my City at 30 psi (the recommended amount is 29) and have never had a blowout in my life.
This does not mean I have not had punctures - no amount of tyre pressure can save you from nails and other road hazards!
There should be an optional accessory that provides a warning to the driver when the tyre temp or pressure exceeds a certain threshold so they can slow down and cool off.
ZPT (Zero Pressure Tyres or ’Run-flats’ as they are called) are also recommended since they can still allow slow speeds (upto 50-75 km/h) with NO pressure.
This is possible with reinforced sidewalls that can support the weight of the car.
For highway driving, tubeless tyres the best.
They have been standard equipment in the US for the last 5-10 years.
No new cars come with tubes at all there.
Not only do they deflate slowly allowing gradual/predictable loss of control, they also heat up less since there is no tube rubbing the insides (friction).
The advantage of tubes is that they are faster and cheaper to fix at any roadside shop in India which is why I stick with them for now.

4. 4WD or AWD
Four wheel drive has evolved through many generations.
It hit mass production with a 2nd gear lever/knob to engage all 4 wheels which is how most 4WD SUVs in India have it currently.
Then it went to a push button system which was much better and easier to use.
Finally the advent of All Wheel Drive (AWD) eliminated the need for human intervention altogether.
It was on all the time and a chip decided when to engage it selectively depending on road conditions.
You can’t really have it fully on all the time since it limits your top speed to around 50-75 km/h in most cases and hogs more fuel.
Audi has some of the best AWD cars on the road today.
Porsche has also recently introduced it in some models since it provides much greater stability and control.
AWD transfers power ’from the wheels that slip to the wheels that grip’ automatically.
Daimler Chrysler introduced the first system in mass production that could transfer enough power to a single wheel to haul the entire SUV (the M-Class) out which was a major achievement.
AWD is to 4WD what auto transmissions are to manuals/stick.

5. Steering wheel audio controls or remote
Why is this considered a safety feature as opposed to a convenience?
If you drive yourself, its important to not look away to adjust/change your radio/tape - if anyone runs out in front of your car (kids, dogs, cows, etc) you will surely hit them.
Steering wheel controls allow one to change the volume with one thumb and the channels/tracks with the other.
I know this is extremely uncommon in Indian cars so a more practical option is also given.
If you have a driver, and you like to listen to music in your car, you should opt for one with a remote.
This allows the driver to concentrate on driving - in fact the cheapest option would be to get a portable system with headphones so you can enjoy your music in peace while the driver can focus fully on getting you safely home.
If like me you don’t want your driver playing around with your system and draining your car battery, get one with a removable faceplate.
It also reduces the chances of theft.