Long term prognosis of a 4 cylinder tow vechicle

[heath74]

Interesting topic, I'll continue to follow it. 
Just returned from a 4000k trip towing a 800-900kg camper trailer behind a 2010 D22 navara dualcab with CRTD2.5 ( with dobinsons suspension upgrade)
I noticed that power was fine for cruising at 100-110km, average 13-14 l per 100k.
The only issue was getting from 100-120 to overtake, and through some steep grades, I was really changing down. From time to time I did feel a bit of 'bounce feedback' from the trailer.
If I was sticking with the car, I'd go chip and zorst for sure.  I would be very reluctant to tow anything significantly heavier with it.
Not sure, maybe my expectations are too high.

[Darcy7]

I think we're missing the point? Power and torque from a 4 or 8 are the same. This notion of nothing beats cubic inches is a thing of the past. A great motor is nothing if the rest is of the stuff around it is crap.

Yep my Patrol is a four pot but it does the job.    My old Disco was a four and it did the job.  Yeah a v8 would be nice but for the money, I'm a happy traveller.

[Bird]

I think we're missing the point? Power and torque from a 4 or 8 are the same. This notion of nothing beats cubic inches is a thing of the past.

Depends how you look at it. Yes the figures are the same, but a larger lazy engine that will do 1,000,000klms standing on its head, or a highly strung donk that stands no chance of 500,000klms or very rarely.. thats what I'm talking bout.
But as I said, dont suppose it matters most people only keep cars for 3-4yrs now, so if its ready to blow up, its someone elses problem... but they are richer than I..

[Maîneÿ . . .]

Depends how you look at it. Yes the figures are the same, but a larger lazy engine that will do 1,000,000klms standing on its head, or a highly strung donk that stands no chance of 500,000klms or very rarely.. thats what I'm talking bout.

How do you differentiate the "highly strung" diesel engine from the "lazy" diesel engine ??

[trekkn]

 a 4 cyl td that makes 114kw and 430nm compared to a 6 cyl td with the same output figures the 6 does it with less strain on the moving parts as its spread over 6 pots compared to the 4 thats why they wear out quicker as they are more stressed and carry more load over less parts

[Dion]

Having recently swapped from the 4.0 straight-6 Petrol Jeep to the 3.2 Di-D (4cyl) Pajero a few observations while towing ....

The Pajero absolutely flogs the Jeep as a tow vehicle in every single respect.  Better fuel economy, better acceleration, better overtaking ability.

My favourite test is the on-ramp from Gaza Rd onto the SE Freeway, southbound.  Its uphill and you can do a run from 0-100 km/h up it with 1400kg camper in tow.
Streetview: http://maps.google.com.au/maps?q=gaza+rd,+holland+park&hl=en&ll=-27.535693,153.061352&spn=0.011778,0.024784&hnear=Gaza+Rd,+Brisbane+Queensland+4121&t=h&z=16&vpsrc=0&layer=c&cbll=-27.534604,153.059201&panoid=3uZuXqslf6StMQ6KoQhcNQ&cbp=12,192.54,,0,0

In the Jeep, I could nail it and it would be a noisy, harsh ride up to 100km/h by the top of the ramp.
In the Pajero ... I nailed it and had to back off at around 120 and still had plenty of road.  

It's like chalk and cheese.

Overtaking while towing with the Jeep required a fair bit of forethought as the pickup from around 80-90 km/h was not inspiring.  With the Pajero I don't even need to do anything special, just pull out and pass.   The Jeep is also about 700kgs lighter than the Pajero, so the Pajero is fighting extra weight as well.  

Modern TDs have come a long way.  

Don't confuse the issue of too small a tow vehicle with the engine choice.  I wouldn't tow a 1400kg camper behind some of the smaller 4WDs, they get bullied around.  The Jeep was pretty light and it would occasionally get pushed around by the camper.  The Pajero is big enough and heavy enough to not be bothered by it.

[Maîneÿ . . .]

a 4 cyl td that makes 114kw and 430nm compared to a 6 cyl td with the same output figures the 6 does it with less strain on the moving parts as its spread over 6 pots compared to the 4 thats why they wear out quicker as they are more stressed and carry more load over less parts

using that same analogy, how would a V8 with 114kw and 430nm compare to a 4 cylinder of same 114kw and 430nm  

[singo-26]

On the basis of an engine being highly strung, Take the number of cylinders out of the equation as to a degree it is irrelevant. What is relevent is the Kilowatt/litre of engine capacity. It is only 20 years ago that a 5l holden V8 was considered powerful with 134kw, now a 200 series landcruiser 4.5 diesel has 200kw. That is how far technology has come. If someone tried to sell you a new holden v8 with 134kw today most would walk straight to ford and buy a turbo 6 with more power and better fuel economy. I've often read of the 3lt patrol (I own one) being too highly strung to be tow, here is the fact.
Gu patrol 3lt          38kw/l
100 series turbo     36kw/l
200series              44kw/l
Which engine is more highly strung on paper.

[Maîneÿ . . .]

Gu patrol 3lt          38kw/l
100 series turbo     36kw/l
200series              44kw/l
Which engine is more highly strung on paper.

Add to that list the Ssangyong turbo diesel 52kw/l  
Bore & stroke: 86.2 x 85.6
Compression ratio:  17.5:1
Kerb weight:  1,873 kg

[Gunna Do]

I was surprised when I saw the following figures.

Navara/Pathfinder: 3.0ltr V6 diesel 173 Kw and 550 Nm

70 Series wagon  : 4.5ltr V8 diesel 151 Kw and 430 Nm

[TheOtherLeft]

Having recently swapped from the 4.0 straight-6 Petrol Jeep to the 3.2 Di-D (4cyl) Pajero a few observations while towing ....

The Pajero absolutely flogs the Jeep as a tow vehicle in every single respect.  Better fuel economy, better acceleration, better overtaking ability.

My favourite test is the on-ramp from Gaza Rd onto the SE Freeway, southbound.  Its uphill and you can do a run from 0-100 km/h up it with 1400kg camper in tow.
Streetview: http://maps.google.com.au/maps?q=gaza+rd,+holland+park&hl=en&ll=-27.535693,153.061352&spn=0.011778,0.024784&hnear=Gaza+Rd,+Brisbane+Queensland+4121&t=h&z=16&vpsrc=0&layer=c&cbll=-27.534604,153.059201&panoid=3uZuXqslf6StMQ6KoQhcNQ&cbp=12,192.54,,0,0

In the Jeep, I could nail it and it would be a noisy, harsh ride up to 100km/h by the top of the ramp.
In the Pajero ... I nailed it and had to back off at around 120 and still had plenty of road.  

It's like chalk and cheese.

Overtaking while towing with the Jeep required a fair bit of forethought as the pickup from around 80-90 km/h was not inspiring.  With the Pajero I don't even need to do anything special, just pull out and pass.   The Jeep is also about 700kgs lighter than the Pajero, so the Pajero is fighting extra weight as well.  

Modern TDs have come a long way.  

Don't confuse the issue of too small a tow vehicle with the engine choice.  I wouldn't tow a 1400kg camper behind some of the smaller 4WDs, they get bullied around.  The Jeep was pretty light and it would occasionally get pushed around by the camper.  The Pajero is big enough and heavy enough to not be bothered by it.

Comparing petrol to diesel is like comparing apples to oranges. Plus it's off topic.

[rotare]

using that same analogy, how would a V8 with 114kw and 430nm compare to a 4 cylinder of same 114kw and 430nm

There is a difference between these power and torque figures.  When people quote figures what you are comparing is the peak figures only which doesn't reflect the true characteristics of the engine.  Put both of the above vehicles on the same dyno and compare the resulting graphs.  What you actually need to compare is the area beneath the graphs, which is effectively the available power and torque from zero rpms to redline.  What you will find is that the smaller 4cyl diesel engines torque will be very "peaky", and will need to be revved out to reach it's maximum torque.

In comparison the bigger engine will likley be making 80% of it's available torque just off idle and maximum torque between 1800-2000rpm.  Big flat torque curves.  Hence why people refer to them "lazy" diesel engines.

For interests sake Mainey, on your vehicle, what does the manufacturer specify the RPM at peak power and torque?

     

[Bird]

I was surprised when I saw the following figures.

Navara/Pathfinder: 3.0ltr V6 diesel 173 Kw and 550 Nm

70 Series wagon  : 4.5ltr V8 diesel 151 Kw and 430 Nm

and which one would you expect to get to 1,000,000klms with the least issues... and door handle replacements

[Maîneÿ . . .]

For interests sake Mainey, on your vehicle, what does the manufacturer specify the RPM at peak power and torque?

Maximum power (kW/rpm) 104 @ 4,000
Maximum torque (Nm/rpm) 310 @1,800

from my observation @ 110 kph is ~2,250 rpm

[Beachman]

In comparison the bigger engine will likley be making 80% of it's available torque just off idle and maximum torque between 1800-2000rpm.  Big flat torque curves.  Hence why people refer to them "lazy" diesel engines.     

That’s a good example as while in my opinion it looked like these 4 cylinder TD were struggling on hills or with strong headwinds. I also noticed the factory TD & V8 Cruiser, 4.2 Patrol and the F250/350 tow these big trailers effortlessly.

[BigBlock1DT6]

The truckies would have loved em soo much!!!!

 

If they would just learn to BACK OFF when being overtaken
and not do 365kmph in overtaking lanes

[Dion]

Comparing petrol to diesel is like comparing apples to oranges. Plus it's off topic.

No different to comparing an old tech N/A diesel with modern TDs. 

The question was posed about how "hard" 4cyl TDs are working while towing.   My view is it is working less hard than the petrol in my old Jeep did, and yet no-one bats an eyelid when recommending 4L 6cyl petrol engines for towing (if you can afford the fuel bill) e.g. Falcon/Commodore/80 series/100 series (excl V8)/Pajero V6/Patrol etc all use six cylinder engines around that capacity.

[Gunna Do]

and which one would you expect to get to 1,000,000klms with the least issues... and door handle replacements

You got me.  Which one has the door handle problem?

[BigBlock1DT6]

My current kenworth ie:RAV 4 tugging a full load 65 tonne all up from brisbane to melbourne at a total of 1668km
burns 1250ltrs of fuel at 550hp every trip and up to 400ltrs more in strong head winds
sitting around 102kmph 90% of the run

My previous Kenworth ie:V8 Landcruiser tugging the same weight and travelling the same kms
burnt 800ltrs with 620hp and an extra 100ltrs in strong head winds
sitting around 104kmph 90% of the trip

If i sat a 60-80 kmph like the grey slowmads
i would burn half that fuel but take up to 9 hours longer to to the trip

I don't pay for fuel so bugger it hold the girl flat tac

result is more HP = less wear and tear
and less HP will cost you a bloody fortune

torque is nothing without horse power to boot

big torgue is great for fuel consumption of flat ground
its horse power that gets you up the hill

small cars = small torgue and horse power = driving slower to get good fuel consumption
flogging a small car while towing would not give it a good long life

[Mace]

Interesting topic - actually discussed it around the camfire two weekends ago (@ Rawnsley Park).

To me its not all about the power/torque of the engine, its also about the gross mass of the vehicle, the weight of the caravan/camper, and the ability of the vehicle to use its reserve power to control any momentum issues with the towed item - ie, at times, reserve power may be needed to pull the caravan out of any centripetal motion at speed, instead of putting on the brakes.

We were discussing the prevalence of D40 Twin Cab Nissans pulling large dual axle caravans.  Many of these vans must weigh  2500 kg, perhaps more.  My view was that I thought that there were more suitable vehicles to pull these vans, such as a Landcruiser.  Now, i have no gripe with the Nissan as a vehicle as such, but lets have a look at the specs:


Vehicle                Tare weight kg           Braked Towing Capacity          kw/torque

D40                     1922 (auto)               3000 kg                               126/403

L/Cruiser 200         2630                        3500 kg                               195/650 

Yes, towing a large dual axle van is within the D40's stated capacity,  They seem to have become a vehicle of choice for towing (perhaps because of cheaper cost).  IMHO tho, id rather be towing such a van with a L/Cruiser (or Troll) as the vehicle has more power in reserve for vehicle control and overtaking, and is less likely to become a pedulum at the end of a van  that is heavier than it in emergency situations.

My opinion only, others welcome.

                     

[WilSurf]

To continue this:
D40: 1922/126 = 15.25 kg/kW
L200: 2630 / 195 = 13.49 kg/kW

So this would mean that the L200 has to move less weight for each kW, should be better for the engine.

[singo-26]

Interesting topic - actually discussed it around the camfire two weekends ago (@ Rawnsley Park).

To me its not all about the power/torque of the engine, its also about the gross mass of the vehicle, the weight of the caravan/camper, and the ability of the vehicle to use its reserve power to control any momentum issues with the towed item - ie, at times, reserve power may be needed to pull the caravan out of any centripetal motion at speed, instead of putting on the brakes.

We were discussing the prevalence of D40 Twin Cab Nissans pulling large dual axle caravans.  Many of these vans must weigh  2500 kg, perhaps more.  My view was that I thought that there were more suitable vehicles to pull these vans, such as a Landcruiser.  Now, i have no gripe with the Nissan as a vehicle as such, but lets have a look at the specs:


Vehicle                Tare weight kg           Braked Towing Capacity          kw/torque

D40                     1922 (auto)               3000 kg                               126/403

L/Cruiser 200         2630                        3500 kg                               195/650 

Yes, towing a large dual axle van is within the D40's stated capacity,  They seem to have become a vehicle of choice for towing (perhaps because of cheaper cost).  IMHO tho, id rather be towing such a van with a L/Cruiser (or Troll) as the vehicle has more power in reserve for vehicle control and overtaking, and is less likely to become a pedulum at the end of a van  that is heavier than it in emergency situations.

My opinion only, others welcome.

                     

It's not only your opinion. My father is starting his grey nomad life with a 23 foot van. he has mentioned a lot of people are not happy with towing the larger vans with utes and Prado size 4wd's, despite the vans being within the towing capacity of the vehicles.


To me its not all about the power/torque of the engine, its also about the gross mass of the vehicle, the weight of the caravan/camper, and the ability of the vehicle to use its reserve power to control any momentum issues with the towed item - ie, at times, reserve power may be needed to pull the caravan out of any centripetal motion at speed, instead of putting on the brakes.


My old jayco is not nealy as nice to tow behind my wife's 95 series Prado as behind a patrol or landcruiser. there are times you can feel the jayco pushing you.

[Bird]

[Mace]

Thanx Lost - thought that might stirr things up a bit!! 

[D4D]

Tail wagging the dog is not something that is enjoyable

Remember this? Legal yes, common sense no