4wd or 2wd towing?

[chappy]

Hi all, firstly let me say that this might sound like a dumb question because I have had little experience ( if any ) with 4wd vehicles so please be gentle with me

We have a D22 3.0L diesel and have towed our 2.5t caravan a number of times now and we are planning a trip across to the west from Adelaide later this year.

The D22 tows well. I usually tow in 2wd in 4th gear at 85-90 Km/h at 3000 rpm and only use 5th when on a flat with no headwind so there is no heavy load on the engine or gearbox and when on a downhill slope, or is it generally ok to tow in 5th gear most of the time?

My other question to you more experienced types is, is it appropriate over long distances to tow in 4wd instead of 2wd? Will this give any real "useable" safety and stability on the highway and also would this use too much fuel or wear and tear on the front hubs to make it a viable option.

I look forward to your advise,

Cheers,

Jeff

 

[tweak'e]

towing in 5th gear is perfectly fine.

using 4wd on hard surfaces is a big no-no regardless if your towing or not. driving on the road on 4wd will simply break the driveline.

 

[Old.Tony]

+1^

If you feel the engine straining, drop it back a cog. You can go in 5th gear up a mild incline and it won't hurt. Diesels are supposed to work for you! Save yourself some juice and just be comfortable with the vehicle. It'll let you know when it's struggling.

The whole purpose behind 4WD is to provide superior traction. If you aren't spinning your back wheels, 4WD is not going to do anything more than create more drag in a straight line.

In a bend, 4WD on a firm surface is destructive. Think about how your car turns a sharp left corner. The rear left wheel follows a very small diameter circle while your front right wheel follows a very large one. The problem is that in 4WD mode you are joining the front and rear together, forcing all 4 wheels to turn at the same rate - and that means either a wheel has to slip (loose surface!) or something in the drive train has to break. Usually it's the transfer chain, but sometimes a CV or axle will let go.

So your instincts were right - 4WD mode isn't needed for general towing. Sure, get onto wet grass or slippery stuff - or a water crossing - go for it, even use 4LO in the water. But out on the hard stuff, you're burning fuel away and throwing money in broken parts.

 

[chappy]

Thanks guys, I appreciate your input,

Cheers,

Jeff

 

[Dave]

What they said.

See a hill coming, drop back to 4th just before the hill.

Whats your fuel consumption like towing the caravan ?

 

[mitch92]

Definitely don't use 4wd unless it is needed. I'm also with dave as above, tow in 5th, drop back to 4th for the hills.

Mitch

 

[Tiburn]

I was in the car with someone who just had to use 4wd towing. as a passenger I could feel the wind up at times and the strain on the vehicle through the very windy roads. It was a Rodeo auto so that has something to do with it but not all of it. He swears that is what they do in Germany, and it is right.

 

[Geoff3DMN]

Some vehicles have full time 4x4 and others have part time 4x4, the Navarra D22 has part time 4x4. It's ok to tow in 4x4 in a vehicle that has full time 4x4 because the 4x4 system is designed for use on hard as well as soft surfaces. Maybe the German vehicles he was thinking of had full time 4x4 but I don't think the Rodeo does...

 

[chappy]

What they said.

See a hill coming, drop back to 4th just before the hill.

Whats your fuel consumption like towing the caravan ?

Hi Dave, So far (not heaps of trips) I've averaged about 16-17 L/Hundred Klm towing at about 90 Km/H in a mixture of 4th & 5th gear. The van weighs 2.5t. We are planning a trip to the west later this year so that will give me a great opportunity to record my fuel usage,

Cheers,

Jeff

 

[Old.Tony]

Hi Dave, So far (not heaps of trips) I've averaged about 16-17 L/Hundred Klm towing at about 90 Km/H in a mixture of 4th & 5th gear. The van weighs 2.5t. We are planning a trip to the west later this year so that will give me a great opportunity to record my fuel usage,

Cheers,

Jeff

That's not too bad. It will improve a bit by using top gear more - I did some rough calculations and figured that each additional 500rpm uses about 2.5LPHK more.

Given that these figures are rough, you could halve them and still use them as an approximate guide.

With gentle acceleration and a cruise speed of 90-95km/h, our auto (on standard tyres) was achieving 15.5LPHK towing our van - a bit lighter than yours, although our Navara weighs in at 2500Kg empty, so we'd guess at 2800Kg with fridge, battery and tools on board.

 

[the_bluester]

I used to use fifth gear regularly in my D22 ZD30 when towing. Basically I used it but not below 90kmh under any circumstances except for when slowing down significantly and then I would downshift when the new speed was reached) and at any time that it would not hold speed of at least 90kmh in top I started going back down through the box.

As per all of the above, dont use 4WD unless the surface is slippery enough to require the traction to keep you rolling or it will wind up the various bits of the powertrain, potentially until something breaks. However in the D22 it can be really handy to leave the front hubs unlocked, allowing you to use 4WD low range to creep around in reverse or forwards when parking a trailer, much easier on the car than slipping the clutch. But you do have to remember to have the hubs unlocked or you are back into windup territory.

 

[Dave]

Hi Dave, So far (not heaps of trips) I've averaged about 16-17 L/Hundred Klm towing at about 90 Km/H in a mixture of 4th & 5th gear. The van weighs 2.5t. We are planning a trip to the west later this year so that will give me a great opportunity to record my fuel usage,

Cheers,

Jeff

I towed a car trailer to Sydney last sunday and towed a U12 Pintara back for a mate.

The whole tank I averaged 10.57L per 100km's.

At the moment I dont have my bullbar on as it got damaged from a roo strike been driving a little slower in general in the kangaroo prone area's.

The intercooler is pretty exposed at the moment which would help. The factory bumper bar is on though.

On the highway at 2am as of late, the pyro has been sitting on 280 C.

Towing 2.2t on sunday, the pyro never went over about 420 C.