Big engine, big power, better economy when towing.

agree entirely, more power easier towing, no brainer.

What brand and model vehicle are you refiring to ?

What were the vehicles..?

Not a good comparison as there are many variables operating with a 4wd which is heavier than the car and has more frontal area, the vans may be different other than the weight, and the engine of the car makes more torque lower down at the towing speed.
Although I agree in most cases a slightly bigger engine will do it bette, it isn't a good example. The sophistication and programming of the ECU's and the change characteristics of the autos will also have a direct effect as does the actual load and running ratios which apply the torque to the ground.

A 2000kg van and an 1800kg van are different weights and possibly frontal area and shape is different too.

I might fit a Rolls Royce Merlin engine 27 litres to tow a 2 1/2 ton van and see what it gets in the economy stakes. Do you think the lock up clutch will be ok?

I think there be a bit more to it than just engine size.

Less than a month ago a friend towed with a 6 litre commodore wagon one of my 1.8 tonne trailers and average 24 lp 100. He complained about how fast the needle moved. He used a light foot.

I towed the same trailer back the following day, and average 14 lp 100 (diesel though) with a light foot.

Commodore 270kw 530nm 6 litre
Disco 180kw 600nm 3 litre twin turbo

I thought torque was the key but he has almost the same as my 3 litre. I guess torque more low down is the key.

So in my comparison back to back......size was more costly at the bowser.

Brett.....

I'm not agreeing or disagreeing with you but you need to provide more info.
Was the tow test done by the same driver? What year were the cars made? Both in a good state of tune? Climate conditions (windy, cold/hot). Driven the same route?

For all i know you could be comparing cars that are 10 years apart in age?
One could have been driven at 80kmh while the other at 100kmh.

Not really "apples vs apples"

wizzer

I think you are bordering on the dishonest by not providing full figures of what you did, comparing a sedan with a 4WD and also not comparing engines of similar technology. Of course a Benz with its super refined technology will perform better than ancient technology.

I consider your post a waste of effort on your part.

Gday Jim
I understand what you are saying, the Benz is better and more enjoyable to drive , even with a van on the back.

has any one bothered to heck the economy figures of the 3 litre grenade in the Patrol while towing 2.5 tonne as opposed to the brunswick chev conversion after the nissan motor explodes.

Might be a better comparison putting a late model electronically over clocked 4 cyl diesel against an old school grunt master diesel in the same vehicle towing the same weight.

16.6" pop top van towed at same speed 100kph - 125kw GQ 4.2ltr petrol 26lph - 101kw 2.5ltr turbo diesel disco 16lph...Just like yours not a fair comparison just shows how different vehicles perform and a bigger engine doesn't always mean you'll get better economy I'd like to how the results went if you swapped the motors over.

This happened in heavy road transport back in the early 90's, all the manufactures went to smaller capacity good HP engines.... like the 11lt Cummins M11, 10lt Caterpillar 3176 and later on the Caterpillar C12. According to the industry it was the way of the future.

Everyone raved about these engine BUT about 10 years ago they all started going to bigger 14-17lt engines with greater HP that gave them better trip time, more economy and longer service life.

Hi Best off Road,
Your post comes at a good time for me as I was actually discussing this motor performance technology with a friend yesterday. I am in the market for a twin cab that will tow a 5th wheeler with a tare weight of 2100kg and an ATM up to 2800kg. There has been a number of recent Threads reporting that some vehicles struggle towing loads up hill etc. I don't want to purchase a vehicle that fails like this.

I am looking at the current crop of 3 to 3.2 L, 6 cylinder, diesels with a towing capacity of 3 to 3.5 tonnes. Obviously fuel economy will be a major consideration in my decision making.

I read with interest and some confusion, the comments in this thread, as I am struggling to understand how an engine that is 2.0L larger, has 191nm more torque , 140kg greater power and 2 more cylinders albeit towing 200kg less weight, can all things being equal, consume less fuel.

As I have indicated in my few previous threads, I have a lot to learn and this forum is helping me greatly, but I have to sort the comments a bit from time to time. If you are able to qualify your experiment details a little more this will assist with my understanding.

Thanks.

Gday Jim,
As a general rule, I reckon your probably right.
There would be cases like an petrol 80 series compared to a new petrol Hilux, which might not get the same results but as a general statement (sorry....opinion!),I agree.
That's what I used for an excuse to the Mrs.to look at a v8 Lancruiser.

PS. be careful what you say on here these days.........opinions aren't appreciated anymore, only pure facts! Write posts as if your writing a uni paper or people can get a bit nasty....LOL

Cheers

3.0 L diesel 580 to 620 Nm, 10 L/100km - why on earth would you tow with a petrol engine?

Bob

Hey Andrew how did you manage extra 2+ tonne on you're F250 yer right.

Hell everyone,
Jim just posted what he had observed. Guess he won't do it again.

As Olcoolone said, they tried the smaller diesels towing freight around this country and they failed big time. Same as many years ago detroit tried a 53 series engine that screamed like a banshee and didn't do the business.

Hell! There was a recent post about a mag testing 4 vehicles, and no one was even interested in the fact that the 200 cruiser was carting all the gear around for the test, both in the back and on the roof. Then included the fuel figures for all the vehicles. How do you get a fair comparison when one vehicle is carrying the load. Not one person here questioned that I believe, and no I don't own a 200 series.

Thanks Jim.

We are on our second 4.0 lt petrol Territory (SZ) and tow a 19ft 1800 kg full size van.
We just completed a 10 day trip from Adelaide, SE, down to Pt. Campbell and back home through Camperdown and the Grampians.
8 days into the trip, I was getting 13.8 L/100, then we had a horrible head wind for the next 2 days and consumption went up to 17/100 but I am chuffed with the big T's towing. ( Actual recordings, not off trip computer) 87 klm /hr when good driving 80 with head winds.
'Pumper'