2WD versus 4WD

[littleriver]

I wonder how some people drive if they need 4H to drive around “more safely” on bitumen. Even on wet bitumen I’d have to make a conscious effort to try and spin the wheels to break traction.

must be running some pretty sticky tyres

NB worth putting up on your profile/avatar you own a NT Pajero (auto/manual) Petrol / Diesel ?





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[Keithyv]

On my previous 4wd (Diesel Terracan) it was part-time 4wd, so only could switch it in on loose gravel / sand etc.
On wet days I sometimes flicked it in every now and again because it was a death-trap for the unwary in the wet. Lots of low-down torque with an LSD on the back means it could be very tail-happy.
Couple that with no traction control or any of that fancy stuff (just ABS) and it was a lot different to the Pajero in 4wd. Traction and stability control plus 4wd capable of being always left on makes a BIG difference in wet weather and slippery driving...

[Patagonia]

I wonder how some people drive if they need 4H to drive around “more safely” on bitumen. Even on wet bitumen I’d have to make a conscious effort to try and spin the wheels to break traction.

Thats like disconnecting the airbags because you drive well, if you have an extra safety feature why not use it, sometimes you only get one chance to use them...

[GHendo]

Thats like disconnecting the airbags because you drive well, if you have an extra safety feature why not use it, sometimes you only get one chance to use them...

I couldn’t agree more. When things go pear-shaped everything happens very quickly and it’s no use then thinking “I wish I’d left it in 4H”. I consider I’m as good a driver as the next bloke but I still want to maximise my chances of getting home in one piece. It’s not necessarily me that is going to make the mistake – it’s could easily be some mindless idiot who thinks he’s the next Steve McQueen and I need to do something drastic to get out of his way. If something does go wrong, I want as many things on my side as I can possibly have.

Geoff

[aussieintas]

I run mine 50% 2wd 50% 4wd....more so to lubricate the 4wd system and when its wet roads. Haven't noticed any difference with fuel economy or wear and tear on anything.

[Dicko1]

I couldn’t agree more. When things go pear-shaped everything happens very quickly and it’s no use then thinking “I wish I’d left it in 4H”. I consider I’m as good a driver as the next bloke but I still want to maximise my chances of getting home in one piece. It’s not necessarily me that is going to make the mistake – it’s could easily be some mindless idiot who thinks he’s the next Steve McQueen and I need to do something drastic to get out of his way. If something does go wrong, I want as many things on my side as I can possibly have.

Geoff

x2. Mines in 4h all the time. If I could predict when I might have an accident then I should be able to pick tattslotto....

[Sparky11]

I wonder how some people drive if they need 4H to drive around “more safely” on bitumen. Even on wet bitumen I’d have to make a conscious effort to try and spin the wheels to break traction.

Not more safely but as safe as I can possibly be, convince me that if i hit some dropped oil or loose gravel on the highway that 4WD will make zero difference then I will go back to 2WD.
Its not always how you drive but other morons on the road can play a big part in it to.

[Pajshomoneroguntero]

CV's are being over driven when in 2wd.... so the wear is on the opposite surface to that which is being loaded when the engine is driving.... if that makes sense..... but as I said I believe that even that argument is academic and that real world practical results will be marginally different between one and the other option

I do get what you mean. As you’ve mentioned mostly academic. I was thinking that the most likely wear would be with the boots and whether 2 or 4wd they are turning.

[flyboy]

In all those scenarios - swerving to avoid someone, hitting an oil slick and sliding - you’re going to brake, not jam the accelerator to the floor.

I can envisage millions of scenarios where maximum braking performance is required, so that’s why the car has four wheel braking and ABS.

Given that liability and safety ratings are everything in car sales these days, if there was any safety benefit in emergency situations on bitumen to having constant 4wd, then the manufacturer would recommend against using 2wd.

convince me that if i hit some dropped oil or loose gravel on the highway that 4WD will make zero difference then I will go back to 2WD.

Okay, so you’re driving down the highway at 80 and a truck carrying glass marbles has dropped thousands all over the road. You hit them unknowingly and the car starts sliding. Your (and everyone else’s) natural reaction would be to:
a) instinctively hit the brakes (hopefully ABS kicks in) and attempt to keep the car straight using opposite steering to control any drift tendency of he back of the car, or
b) bury the accelerator.

Anyway, just my opinion and happy to be disagreed with.

Like others, I cycle through the modes reasonably regularly (including 4L and the diff lock momentarily when possible). And I definitely use it when towing, as recommended.

NB worth putting up on your profile/avatar you own a NT Pajero (auto/manual) Petrol / Diesel ?

Yes good idea, I’ll get onto it.

[Keithyv]

4wd advantage on bitumen is mainly taking off and accelerating around corners and bends in the wet and up slippery hills IMHO. Stopping and trying to avoid an obstacle while braking is not going to make much difference..
I've had cars go sideways just accelerating up a hill, do 360's taking off around a corner (okay maybe when I was younger and a bit heavier footed)
Still, 4wd makes this a LOT less likely to occur.

[Patagonia]

Avoiding and obstacle while braking or not, 4h has a lot of advantage in mantaining control.

4h means less stress in transmision and tyres, only advantage of 2h is fuel economy but apparently on newer Pajeros is not significant so its really a no brainer: less car wear, more safety, insignificant fuel cost.

On my NL I recall fuel usage was more signigicant.

[Nab]

I always had mine in 4H. There were a few times when I had accelerated around a wet corner and the inside wheel slightly spun and I lost all power, quite heart stopping when in heavy traffic!!!!


I can't see any advantage in keeping it in 2H, not sure why it is even an option...

[Patagonia]

At this point I think its only a marketing issue, one more feature for the sales brochure and more important to show better numbrers in the fuel economy line, this can even mean less taxes in some countries despite the small difference between 2h and 4h

[benckj]

I always though the ASC would transfer load to other wheels if one began to slip. This would happen regardless of being in 2wd. Correct me if I’m wrong.

I tend to always drive in 2wd and only flick over to 4wd when I need it. Might consider changing this habit after reading this thread. I’d like to understand the mechanics behind operation first.

[Pajshomoneroguntero]

I always though the ASC would transfer load to other wheels if one began to slip. This would happen regardless of being in 2wd. Correct me if I’m wrong.

I tend to always drive in 2wd and only flick over to 4wd when I need it. Might consider changing this habit after reading this thread. I’d like to understand the mechanics behind operation first.

No. At low speeds the ASC will cut power. The changeover to not cutting the power is something like 30kph but I’m guessing on the exact figure.