[shuvc]

Originally Posted by Abhay

yes shuv, some power is lost in running the AC but I didnt understand what you meant by when car is stationary, no torque

I guess I got muddled up there ! Mechanics/Dynamics don't agree with me !

Any idea what % of power or how many HP, an AC typically consumes ?

[santosh.s]

Originally Posted by vivekiny2k

well, the only observation being I cud feel the AC vents even when the engine is not started (just turned the key to switch on the panel etc).

may be it's just the fan and not the AC. but there is no place other than battery where it could
draw it's power from.
right?

I too think so.... it must be just blower fans and may be some cool air left in AC ducts.
I don't believe normal lead-acid batteries in cars have enough capacity (like most of other
batteries too) to run an A/C system.... not very sure though

[Abhay]

vivek, air does come from the vents but its just the blower not the a/c !
a/c starts only when engine is running since it runs the a/c compressor
and yes battery runs teh fan/blower/stereo etc when eengine is off

[merve_extreme]

The AC blower is run by the battery and the compressor is run by the engine crank using a belt driven pulley.to run the compressor the engine need to use some of its power and hence there is some loss of power.

the chargine of the battery requires negligible engine power since the alternator also runs on the engine crank but requires far less effort from the engine to move it.

[turbo_lover]

off topic -
has anyone noticed a decrease inbraking power when the a/c is on?
i noticed it in the Alto ,it has booster assisted discs ..
whats the deal with that?

Power steering also lowers engine power as much as 5% at times...what i want to know is which consumes lesser power? electric ps or hydraulic?

[shuvc]

Originally Posted by turbo_lover

Power steering also lowers engine power as much as 5% at times...what i want to know is which consumes lesser power? electric ps or hydraulic?

Found this ...
http://www.freescale.com/webapp/sps/...02Wcbf07jS1504

It says ..
HPS consumes around 5 HP !!
EPS consumes less power .. but

"The steering assistance possible for any EPS system is limited by the maximum current available from the vehicle. Typical 12V systems can provide a peak maximum current of 80 amps, limiting peak power to only 1 Kilowatt, so current applications of EPS are limited to smaller vehicles, such as the compact or smaller medium class of cars. However, once 42V electrical systems are available, EPS can be easily applied to larger vehicles, even trucks."

Which cars, C segment and above have EPS ?

[merve_extreme]

Originally Posted by turbo_lover

Power steering also lowers engine power as much as 5% at times...what i want to know is which consumes lesser power? electric ps or hydraulic?

Ofcource electric power steering.it uses none of the engines power as it runs on a electric motor wich is powered by the battery as oposes to hydraulic systems which need to run a compressor which runs on the engine power(i:crankshaft).

[raja_ys]

i have heard that keeping a slight higher pressure than recommended increases mileage, if this is true does the power or tourque get affected by higher tyre pressure?

[Abhay]

no power & torque will not be affected really sicne you are not doing anything to the engine....but your ride quality might suffer (bumpy, bouncy ) and mileage will slightly increase due to less friction with road.

Why do I get the feeling that all your questions are only regarding increasing mileage?

[turbo_lover]

thanks for the info merve and shuvc

Which cars, C segment and above have EPS ?

starting from the
suzuki's(all),accent ,santro,optra,NHC,OHC,Lancer ,corolla ,octy list is long...

palios , indicas ,corsas have hydraulic power steering ...

[filcord]

Originally Posted by turbo_lover

starting from the
suzuki's(all),accent ,santro,optra,NHC,OHC,Lancer ,corolla ,octy list is long...

palios , indicas ,corsas have hydraulic power steering ...

I beg to differ on the Suzukis. The Baleno at least has hydraulic power steering.

[Shan2nu]

Boy do i hate EPS. And after the NHC, Honda has realised that too and has decided to launch the next gen Civic with the conventional HPS.

EPS is good within city limits but, once you hit the highways, they lack the precision and feel that a HPS offers.

I'd rather sacrifice 5% of engine power than sit there with no feed back.

Shan2nu

[Shan2nu]

i have heard that keeping a slight higher pressure than recommended increases mileage, if this is true does the power or tourque get affected by higher tyre pressure?

Well, it won't affect power and torque directly. But, the car will get a little quicker since the rolling resistance is being reduced.

You will see this especially in your rollon figures.

Shan2nu

[raja_ys]

bc petrol is rs50.50ps in hyd and is slated to touch 100rs by the time upa govt comes down. these days its easier to purcahse a car than driving it.

[raja_ys]

maruti wagonr has eps, thats for sure