[jinojohnt]

Originally Posted by mayankk

I think the sensors react to deceleration rather than impact. Or in addition to. But most definitely it's not just a button that needs a direct impact.

There are different types of sensors. Some cars have impact sensors only, while others have impact sensors + deceleration sensors. I was talking about a new design for impact sensors.

[mayankk]

Originally Posted by jinojohnt

There are different types of sensors. Some cars have impact sensors only, while others have impact sensors + deceleration sensors. I was talking about a new design for impact sensors.

Which cars have only impact based sensors?

[jinojohnt]

Originally Posted by mayankk

Which cars have only impact based sensors?

My bad - I read some articles that talked about earlier generation cars that have only impact sensors. I guess modern cars have deceleration sensors to detect rate of decrease of speed, as you said.

[jinojohnt]

Originally Posted by mayankk

Which cars have only impact based sensors?

Many threads talk about Airbags failing to deploy as the impact was NOT in the exact position of the sensor. Something missing? Aren't they supposed to trigger based on deceleration?
http://www.team-bhp.com/forum/techni...ml#post3585724
http://www.team-bhp.com/forum/techni...ml#post3585961

[mayankk]

Originally Posted by jinojohnt

Many threads talk about Airbags failing to deploy as the impact was NOT in the exact position of the sensor. Something missing? Aren't they supposed to trigger based on deceleration?
http://www.team-bhp.com/forum/techni...ml#post3585724
http://www.team-bhp.com/forum/techni...ml#post3585961

My take is the deployments did not happen because of some flaw in the design, or the manufacturing.
If any cars are using sensors which activate because of a switch which needs to be pressed like this, rather than an inertial system, they should be taken to court.
And I don't believe you will find ANY manufacturer who have installed such a system which requires a direct impact only on the sensor itself.

[jinojohnt]

Another one:
Fuel tanks are mostly placed between the rare wheels ('safest' position, as per conventional wisdom).Why can't the manufacturers be innovative and find new positions for the fuel tank?

Case in point - The new Honda Jazz has the fuel tank under the front seats, and it frees up a lot of space under the second row seats.

Most of the 7 seaters in today's market have a 'namesake' third row that forces you to sit in knees-up position. If the position of the fuel tank is changed, you can easily design a very usable 'third row'.

[jinojohnt]

Another one, this time for bikes though:
I see many bikes with tires worn-out at the center of the tread, but with good tread on the sides. This is especially true in bikes where the tires are not flat like car tires (i.e, treads are curved/round to accommodate tilting of the bike during cornering).

Isn't it possible to design tires with less treads on the side and bigger treads on the center so that the tires wear out more evenly? This reduces the wastage of rubber.

[anilp]

Originally Posted by jinojohnt

Isn't it possible to design tires with less treads on the side and bigger treads on the center so that the tires wear out more evenly? This reduces the wastage of rubber.

It's already being done on many bike tyres. What the manufacturers do is that they use rubber compounds of varying hardness. The central part is a harder compound, whereas the sides use a softer compound for grip during cornering. It's usually tyres meant for high speed performance riding (like Metzeler M5s) where you get "chicken strips" in the centre if the riders are not much into aggressive cornering.

[jinojohnt]

Why is it that automatic cars have a 'creep' feature in 'Drive' mode?
I am more comfortable with the old 'Kinetic Honda scooter' type of automatic where Accelerator input is needed for moving forward.
If I need to start off from an incline, I can very well use the hand-brake (just like I do in Manual Transmission cars).
I find the 'creep' feature more irritating because it affects my slow-speed braking, and also has a risk of moving forward if I take my foot off the brake.
(I am used to taking my foot off the brake immediately after I stop momentarily, in Manual Transmission cars).
Is there a technical reason for the 'creep feature'? Why can't automatic cars be designed without this?

[anilp]

Originally Posted by jinojohnt

Why is it that automatic cars have a 'creep' feature in 'Drive' mode?
I am more comfortable with the old 'Kinetic Honda scooter' type of automatic where Accelerator input is needed for moving forward.

It's recommended that you put the auto transmission car in N for slightly longer stops, say 15 seconds or more. Else it takes a toll on the brake components. I believe that the creep is largely a feature kept to keep you moving easily in bumper to bumper traffic.

[jinojohnt]

Originally Posted by anilp

It's recommended that you put the auto transmission car in N for slightly longer stops, say 15 seconds or more. Else it takes a toll on the brake components. I believe that the creep is largely a feature kept to keep you moving easily in bumper to bumper traffic.

Thanks, but I was referring to short two-second stops due to traffic.
Also, my old kinetic Honda scooter did not have the creep feature, but yet was comfortable in bumper to bumper traffic. I think the creep feature has some thing to do with technical limitation than driver convenience. Can experts please clarify?

[Rahul Bhalgat]

Originally Posted by jinojohnt

Another one:
Fuel tanks are mostly placed between the rare wheels ('safest' position, as per conventional wisdom).Why can't the manufacturers be innovative and find new positions for the fuel tank?

Case in point - The new Honda Jazz has the fuel tank under the front seats, and it frees up a lot of space under the second row seats.

Most of the 7 seaters in today's market have a 'namesake' third row that forces you to sit in knees-up position. If the position of the fuel tank is changed, you can easily design a very usable 'third row'.

Yes, good observation.

Honda Jazz is a good example of freeing-up space in the rear. But I noticed compromise in the sitting position of the co-passenger and eventually I found that it was due too fuel tank being placed there.

So, there will be a compromise somewhere. In utility oriented practical cars, the rear space shall be considered more important and in other cars, the present position of fuel tank looks alright.

[a4anurag]

Originally Posted by jinojohnt

Another one, this time for bikes though: I see many bikes with tires worn-out at the center of the tread, but with good tread on the sides.

Isn't there the role of air pressure that is maintained in the tyres to influence is wear and tear apart from driving style?

An over-inflated tyre will have more central area contact as compared to a correct inflated tyre. I may be wrong but just a thought.

[jinojohnt]

Originally Posted by a4anurag

Isn't there the role of air pressure that is maintained in the tyres to influence is wear and tear apart from driving style?

Thanks anurag for pointing out. Your point is more relevant to car tires that have a 'flat' contact area with the ground. (Over-inflated tires wear out more in the center, while under-inflated ones wear out at the sides.)
Many bike tires have a 'curved' point of contact (to accommodate tilting while cornering). Hence such tires wear out at the center faster (even with correct air pressure), unless you do a lot of aggressive cornering.

[jinojohnt]

Another one:
'Invertor Type' air-conditioners are the current rage in home air-conditioning, with tall claims of electricity savings owing to continuous running of compressor at a reduced speed.

Why are manufacturers not using this technology in car air-conditioning, if mileage benefits are good? It would also help avoid the jerk in small-engine cars when the compressor goes on/off.