Toyota RAV 4WD system-Edmontonsky is wrong

HRU

In a topic about a guy wants to buy a new SUV, a guy named Edmontonsky said somthing about 4WD of Toyota Rav4.

His idea is totally wrong.

% H7 ]  h& @  j8 Z6 K! WToyota 4WD drive is a hybrid 4WD system. When it is in normal, computer can detect any slips of front wheels and then transfer more power to the back make it is nice to drive on slipery road. If the road is good enough, it is 95%-100% power to the front wheels to save on gas.
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When engaged into 4Wheel Lock, it is a 50% 50% split power and locked differential. It increases the torque to handle very bad road condition. You are not supposed to drive over 40km-60km/h, otherwise, the system will automaticlly switch to AWD automatic status.

; t7 M/ F. D) n) u5 i  {+ n8 @There are automatic ONDEMAND 4 wheel drive systems (Toyota RAV4 Honda CRV Ford Escape)  and full time 4WD system (Suzuki, BMW Mercedes Benz 4matic Subaru, Acura MDX Honda Pilot)

6 k# Y9 E* g$ V: d4 `1 p9 zLock in can be on either of these guys.

fr5404837

More details will be better

大连人

Zhujiaolian

燕子山

it's a lot more complicated than that. I blame it on the manufacturers and magazines who use the terms interchangably. There are variations on a theme, of course, but this is basically what it boils down to:
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4WD = Low range and High Range gearing
* U  `! k4 V' U+ D4 hAWD = Only high range gearing
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Part-time 4WD: No centre differential. Cannot be used on dry/wet, semi-slippery roads due to the lack of the centre differential. When activated, both front and rear axles are physically locked to each other and have to spin at the same rate. This becomes a problem when turning on sufficiently high friction surfaces. Examples: Suzuki SUVs, most 4WD pickup trucks, cheaper SUVs.

Permanent 4WD:. No two wheel drive mode. System is equipped with a centre differential, and hence is safe to use on all surfaces. All four wheels are powered all of the time (usually 50/50 front and rear axles). This is arguably the best system since the torque split ratio does not change and is the most predictable. All wheels "help out" all of the time and this stabilises the vehicle + improves handling. With the extra two drive wheels, the vehicle has twice the amount of traction all of the time (even in no-slip conditions) vs. a 2WD vehicle. Examples: MB M-class SUV, the Range/Land Rovers.

Full-time 4WD: Basically permanent 4WD but with a 2WD mode. This was born out of customer demand (for a 2WD mode). Examples: Toyota Sequoia, Mitsubishi Montero.

Permanent AWD: Basically permanent 4WD but without low range gearing. Examples include the Audi Quattro AWD system, the MB's 4-matic AWD system, Subaru's manual transmission AWD system.

Full-time AWD: System is active at all times, however in most cases, the one set of wheels (usually the rears) only receive 5-10% of the engine's power unless slippage occurs. At that point, power is progressively transfered to the opposite axle to help out. Some systems can transfer power to the rear upon acceleration to improve traction. However, they revert to 2WD mode when coasting.

Hope this clarifies things for everyone!

挨着门洞

汗

fr5404837

多谢，很专一