Techonologies in cars

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parity

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Hi all car lovers :D
Plz tell me
-> Wats this 4 wheel drive in cars ??
-> Is it same as 4x4 written on some cars ?
-> Is this technology only for SUVs n Sedans or for any kind of car ?

I have lots of queries, as i am crazy for cars :cool: wud post all one by one :D

I know i can find all this on net but knowing from a Jat gives a better feeling :D
 
Most cars have 2-wheel drive. It means that the car's engine propels either the front pair or the rear pair of wheels.

If a car is a front-wheel drive (FWD), then the engine propels the front pair of wheels.

If a car is a rear-wheel drive (RWD), then the engine propels the read pair of wheels.

Some sports cars are RWDs because a higher horsepower is utilized more efficiently in pushing as opposed to pulling in the case of FWDs.

Most Sedan's are FWDs. FWD is a conventional concept.

Then comes the 4-wheel drive or all-wheel drive (AWD). Such a design is suited for vehicles with humongous engines because of the energy needed to propel 4-wheels compared to 2-wheels.

Most SUV's and pickup trucks come with 4-wheel (AWD) and 2-wheel drive variants. The AWD models cost more.

Such vehicles are good for bad terrain driving because each wheel needs more energy in such situations. AWD gives the driver a better grip over the terrain.

No, all cars that have AWD or 4-wheel drive written on them are'nt actually AWDs; especially in India where people put twin-cam-16 valve stickers on their single-cam- 4 cylinder maruti cars. You can put one such sticket on your moped. No one cares.

In the US, cars with 4-wheel drive or AWD stickrs on them are very probable to be 4-wheel drives or AWDs. Many people in the US are off-road enthusiasts. They have such vehicles for personal, or professional reasons, depending on where they live, work or have fun.

From my personal experience, AWDs are a lot of fun for off-road driving. They hardly make any difference while driving on paved roads. You wont even feel the 4-wheel drive when driving on an interstate.

In India, I think the only 4-wheel drive that I am aware of is the loyal Military Jonga. I dont know if Maruti Gypsy or some Mahindra and Tata vehicles are 4-wheel drive now. There were hardly any AWDs in INdia 6 years ago.

Ask any question you feel
 
4WD and AWD systems explained

A word of caution first. Manufacturers tend to hide the real nature of their 4WD systems behind phantasy names like "real time 4WD" etc. - others might call their system AWD when it is clearly not. Make sure you get what you really need.


4WD has been invented a very long time ago and various concepts have been tried. Here is a simplified synopsis of what is what. They are all 4WD, but have been given different names. Links within this page provide detailed insight.

Part time 4WD is a system that can only be used part of the time in four wheel drive.
This 4WD system was created to provide a vehicle with more traction to either carry higher loads and/or to travel in adverse terrain conditions. Clearly purpose built to do hard work. It can only be used for adverse terrain conditions - not for dry pavement.
Typical lever settings are 2WD, 4WD Hi, 4WD Lo.
Very good off-road. Most competent when combined with axle differential locks.
• 2WD setting must be used on dry pavement.
• If 4WD is selected, all 4 wheels are permanently powered.
Prominent examples: 1942 Willys, Jeep Wrangler.


Full time 4WD - also called permanent 4WD, can be used full time on all surfaces including pavement.
Full time 4WD was created to provide a vehicle with more traction and to make 4WD more useful for everyday life. The additional feature of a differential incorporated into the transfer case makes it possible to use 4WD all the time.
2WD is no longer available. Can still be a strong workhorse. Some rough terrain competence is retained - the priority is added stability as a safety gain for everyday driving.
Typical lever or switch settings are 4WD Hi, 4WD Lo. Very good off-road when center diff is lockable. Even better when combined with axle differential locks.
• All 4 wheels are permanently powered.
Prominent examples: pre 2006 Mercedes M-Class, Mercedes G500, LandRover, RangeRover.


Full time symmetric AWD is similar to full time 4WD - only it lacks the slow speed torque enhancing low range feature. Can be used full time on all surfaces including pavement.
Symmetric AWD was created as a safety feature for modern day vehicles. Not designed for hard work. Clearly a safer, more comfortable vehicle. Rough terrain competence has almost vanished - focus is on added stability and performance.
Limited use for off-road.
• All 4 wheels are permanently powered.
Prominent examples: 2006 Mercedes M-Class, Audi Quattro, most Subaru, pre 2006 RAV4


Automatic asymmetric AWD was created solely as a stability enhancing system. Auto AWD can be used full time on all surfaces including pavement. AWD only briefly activates automatically when stability threatening conditions arise. Essentially a 2WD car with 2WD handling characteristics. Absolutely no adverse terrain capabilities. Clearly built for added road stability and safety.
Not recommended for off-road beyond graded dirt roads.
• 2 wheels are powered most of the time
• 4 wheels are only temporarily powered.
Prominent examples: Volvo AWD, 2006 RAV4, Honda CRV.

A more detailed explanation of the differences between 4WD and AWD.

So, is "real time 4WD" really 4WD? No, it is a sophisticated 2WD car with automatic asymmetric AWD. There is no commonly accepted standard - companies and especially their PR departments use terms for 4WD systems very loosely - transparent consumer information is not their priority.

Many vehicles are offered with a combination of the systems outlined above.
 
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Thanks

Thank u Sumit n Sunita for explaining so beutifully :)

Any relation between 4 wheel drive or AWD & mileage of the vehicle ?
I guess not :D but plz tell.
Is this mean that it can be used only in powerful vehicles ?
 
parity said:
Thank u Sumit n Sunita for explaining so beutifully :)

Any relation between 4 wheel drive or AWD & mileage of the vehicle ?
I guess not :D but plz tell.
Is this mean that it can be used only in powerful vehicles ?
Click to expand...
er

Ofcourse AWDs gulp more petrol compared to non-AWDs. Such cars have bigger engines that produce higher torque, which needs more petrol.

Engines have to be a certain specification to handle AWD capabilities of a car. You cannot have a meaningful AWD in a Maruti Car with a 800 cc engine.

But, dont miss the point. The main reason people buy AWDs is because they need more power in their wheels.
 
Sumit bhai AWD ka to karda parcha chhaap diya dyaki...ye saari florida ki AWD te taane dekhte he daank maarengi beri
 
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In old mahindra and gypsy, one had to adjust the hubs manually for 4*4 operation....there is an option in 4wd i.e 4 low and 4 high

4 low...>>> engine can give u instant pick p but cant touch the top end...like ,, machine touches 100 kmph in second gear,,but after applying 4 low speed`ll decrease to 60kmph .....u can use 4 low in sand dunes ....;)

4high ..>>>engine cant give u instant pikp but can touch the top end..now engine`ll cut out at 130 in second gear....after touching the top end engine starts giving sound like PPPPPPPPPP....:)

u can shift the lever 4low to 4 high any time but u cant shift it back to 4low..for that u have to stop the car.....

i lv suvs for their off-road style...

my fav off-roaders >>>> gypsy and mitsubishi strada {in the pic}
 
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Indeed gud informative inputs from Sumit, Rupi & last but not the least Hoods Bolero aali :rolleyes: ;)

Rock on
Jit
 
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downtoearth said:
In old mahindra and gypsy, one had to adjust the hubs manually for 4*4 operation....there is an option in 4wd i.e 4 low and 4 high

4 low...>>> engine can give u instant pick p but cant touch the top end...like ,, machine touches 100 kmph in second gear,,but after applying 4 low speed`ll decrease to 60kmph .....u can use 4 low in sand dunes ....;)

4high ..>>>engine cant give u instant pikp but can touch the top end..now engine`ll cut out at 130 in second gear....after touching the top end engine starts giving sound like PPPPPPPPPP....:)

u can shift the lever 4low to 4 high any time but u cant shift it back to 4low..for that u have to stop the car.....

i lv suvs for their off-road style...

my fav off-roaders >>>> gypsy and mitsubishi strada {in the pic}
Click to expand...

Thanx :) But Sir Ji ye "4 low & 4 high" kya hai ?
 
parity said:
Hi all car lovers :D
Plz tell me
-> Wats this 4 wheel drive in cars ??
-> Is it same as 4x4 written on some cars ?
-> Is this technology only for SUVs n Sedans or for any kind of car ?

I have lots of queries, as i am crazy for cars :cool: wud post all one by one :D

I know i can find all this on net but knowing from a Jat gives a better feeling :D
Click to expand...


well so far so gud really nicely explained by members...

further sukarma few basic things to keep in mind.....

1. 4 wheels consume fuel like anyting... and more so the speed and initial acceleration is also hampered to a great extent so permanent 4WD is useless and i guess isnt also available in india......

2. in india there r many varients ... age old Gypsy (i luv this machine), TATA safari, scorpio, Ford endauver, nissan X - trail, pajero, parado, audi n many more (sumit many models were very much here even 6.....(10) years back)

3. in applied senses and for all practical purposes 4WD is used once in a blue moon here....

4. they r expensive then normal ones so buy if u reallly need to travel through rough patches and are an adventurer.

5. i wonder if any sedan has a 4WD

6. u said urself.... in india 4X4 written on it means nothing except the guy driving it is a freak...... like in many cases u would find TWIN CAM 16 VAULVE written on a maruti - 800..... hahhahahahhahaa.... even u would find it on safari's and scorpios written falsely... i juss donnno why ppl do such things.... may be inferiority complex......hahhahahahhahahaa
 
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