Max speed in 4WD?

[kwilko]

What is the recommended max speed with 4WD engaged?
Navara D40 6sp 2.5 diesel.

 

[KraftyPg]

Arguable, but it's recommended not to run 4wd in bitumen/hard surfaces.

 

[kwilko]

So what is the recommended max speed? I'm assuming that the vehicle is on the approprate surface.
I would have thought the mfrs or someone has some guidelines for this.

 

[jason-navara]

the way i was brought up was

try to avoid using 3 gear or up in 4wd low, and a top speed of roughly 80km in 4wd high.

 

[KraftyPg]

In most cases the appropriate surface would dictate lower speeds than is theoretically possible.

If there is a maximum I'd imagine they would write it in the book in the same section as the discussion about the 4wd selector which they suggest can be engaged at any speed up to 100kph, or below 100 I can't remember the wording.

In 4H I've easily done 80+ in mine and other 4wds but I've never looked at the speedo to confirm exactly how fast I was going.

 

[kwilko]

Yes- they recommend engaging below 100 km but don't appear to stipulate a max speed. (talking hi ratio here).

 

[KraftyPg]

Well I don't know of too many places you'd want to be in 4wd at over 100 but Yota claim the FJ will do nearly 150 in 4H. Given the Nissan Australia don't seem to like upholding warranty on 4 wheel drives that have been used as 4 wheel drives I can't see them actually putting a maximum figure it in case someone tries it.

Edit: I just looked in the Pathy manual (because I'm too lazy to eject the CD and put the Nav one in) and in the brief look I can't find anything that states an exact speed. However the general idea still seems to be, if you're going fast enough to consider that it could be a problem then the road is more than good enough to be driven in 2wd.

 

[kwilko]

I drive a lot in Laos where the roads are to say the least variable, asphalt, to hardcore to landslide to sand etc etc - this involves sometimes being in 4WD when it might not really be needed but one forgets to turn it off etc....

 

[KraftyPg]

Personally at speeds under 100 I wouldn't be bothered.

 

[kwilko]

bothered about what?

 

[KraftyPg]

anything

 

[4x4 ST-R]

I've seen on some vehicle info plates to avoid going over 50km p/h in low range. Makes plenty of sense, cos if your going to go faster you would go up to 4H. Sometimes laziness would be a key contributor here.

 

[KevinE]

I have no idea about the D40, maybe have a look in your owner's manual? I have a 2010 D22 2.5 Diesel 5 speed & the max speeds recommended for each gear in 2H, 4H & 4L are printed in my owners manual.

 

[Peter ST_R]

The 4wd drivetrain pieces are as strong as the rest of the drivetrain so go what ever speed you feel safe driving over the surface at. Smooth high speed driving is typically low stress on the drivetrain compared to low range driving which produces more torque on the drivetrain. There are a lot of full time 4wd vehicles out there that go faster than a Navara. I have driven many hundres of kilometers of dirt road in 4H at 100Km/hr with no problems with improved handeling but as others have said don't drive faster than is safe just because you are in 4wd.

 

[kwilko]

So there seems to be a bit of a dichotomy here.
On on hand some advise a max speed of 80 kph, whereas the manufacturer suggestes that 4WD can be engaged at speeds up to 100 kph.

I have to say that my Mitsu Strada felt to be a much stronger vehicle and on one occasion I used 4WD on a newly wet asphalt surface I think it saved me from a serious accident. I drifted wide on a corner and noticed 10 - yes 10! - pickups sitting in various positions on the verge and ditch where they has slid off.

I'm a life long motorcyclist and farm boy, I have spent most of my driving life looking at road surfaces and guestimating how slippery they may be, so I would use 4WD on asphalt or any other surface if I determined it would be safer to do so.

 

[KraftyPg]

Well I don't believe 4wd is safer than driving properly on wet and slippery roads no matter what their construction. 4wd is often a false security for safety when slowing down and driving to the conditions is the better option. But I think you are looking for a theoretical figure that doesn't exist in the real world because it's dependent on too many factors.

You can engage 4wd at speeds of up to 100kph as per manufacture recommendation and they also suggest you don't drive faster that that in 4H (50 in 4L) but an exact figure doesn't exist.

 

[kwilko]

if I'd been in 2 WD the whole nature of driving on a surface that was nearer to ice would have been different.a reason for 4WD is to improve traction - it certainly did that.
I think you need to look into the physics of 4WD.

 

[KraftyPg]

A reason for 4wd is to improve traction under some circumstances not all circumstances. However I still stand by what I said. 4wd is often used as a false security for safety when driving to the conditions is a better option.

I looked at the physics of my 4wd and still came to the same conclusion.

 

[Peter ST_R]

A reason for 4wd is to improve traction under some circumstances not all circumstances. However I still stand by what I said. 4wd is often used as a false security for safety when driving to the conditions is a better option.

I looked at the physics of my 4wd and still came to the same conclusion.

Totally agree with you on this! Most handeling aspects remain the same in 4wd or 2wd, only benifit of 4wd is slight increase in traction under acceleration. Don't drive faster because you are in 4wd, the fact you are in a 4x4 means your vehicle probably has poor handeling from the outset compared to a 2wd sedan.