Thread: Which engine for towing?

To quote a famous saying;
When it comes to towing.
"there are no substitute for cubic inches". (or cc)

All manufacturers including Land Rover are fitting smaller engines which rely on their turbocharging to make power, for many reasons non of which include heavy towing, especially in our climate.
If you are going to regularly tow more than 2.5t then I would go for the TD6.
I recently retired my Disco2 TD5 from towing our van and bought a Rangie Sport TDv8 to tow the van which is the same size/weight as yours.

For what it's worth I have 45 years experience as a heavy Diesel mechanic and own 2 Rovers.
Cheers.

that saying is pretty long in the tooth, technology has come a long way, consider your td5 did the job and even if it was remapped it would fall 100 or so nm below the standard sd4 not to mention the power deficit , the extra 4 gears etc , methinks the sd4 will be fine for the job , if it was constantly towing 3 tonne plus then it might be worth considering the td6 you'll also save a bit on fuel with the sd4 but only when not towing. I tow a 2.2 tonne yacht with my disco3 tdv6 in which i have a tune around the same torque as sd4 but my disco weighs 2.7 tonnes and 6 speed , still plenty :-)

It's all about torque.

Torque used to be a product of cubic inches, or stroke to be more precise. Designers have tried to replace cubic inches with forced induction, getting the same amount of fuel/ air mix in a smaller chamber.

Sounds great, doesn't it? But there's no such thing as a free lunch. The more you rely on forced induction to boost torque the more compromises you will make. Heat and turbo lag spring to mind. Don't believe me? Take a V8 Commodore for a test drive (while you can). Feel torque from cubic inches, then drive a turbo with similar torque figures. You will not feel the creamy, smooth torque that only capacity can provide.

As technology is used to increase output from smaller motors I'm certain reliability comes into the equation. And, on hot days, turbos do not generate anywhere near their potential power. Ever wonder why Euro turbos that have an overboost capability don't have them enabled for the Australian market?

Don't be misled by the attraction of better fuel economy with a smaller motor. In the real world it doesn't happen. You need x amount of fuel to move a vehicle weighing y at z kmh for w kilometers. A six cylinder Commodore uses about the same a an eight, any difference comes about because we all open the throttle about the same amount to get moving, so the 8 consumes more (but gets to speed quicker). On the open road, with little speed variation, the difference is negligible.

If I was selecting between motors with towing in mind I'd get the biggest motor using my preferred fuel. It will do the job better, and IMHO for longer. I'd also expect the bigger donk to have a much better resale value...

V8 commodore ? OK then
V8 commodore 1700 kg drag coefficient 0.31 , 6.2 v8 , torque 570 nm , average 12 l / 100
Discovery 4 2700 kg drag coefficient 0.4. , 3.0 v6 , torque 600 nm , average 10 l / 100
Wonder what the 6.2,s fuel consumption would be if it was in the disco ?
I love a v8 petrol as well but they are not efficient and also don't put out as much in the heat , that's just to do with air density, the new generation of Brit and euro diesels are incredibly efficient , modern metallurgy also makes them reliable , sequential turbos deliver the torque smoothly , whichever way you look at it turbo diesel is what you use for hauling stuff and 500 nm is enough for the op's requirements when you consider the 400 + kilos weight reduction on the disco 5

I don't know why they turbo all those truck engines, they just have to make them bigger to get the same torque and fuel efficiency.

The new ingenium is still an unknown for towing at this stage, it may be very good or it may not be tuned well. I would be waiting for some real world experience or if you can't wait buy the TD6.

Originally Posted by Geedublya

I would be waiting for some real world experience or if you can't wait buy the TD6.

I think this is the answer I needed to be told

Hopefully some one will tow test it before I need to put my order in.
Cheers.

I have the Ingenium 132kW, which is the equivalent of the TD4, in my DS. I certainly wouldn't like it in the heavier D5. The SD4 has a lot more torque on paper so it may be OK.


Although it is getting better with a few thousand km there is a lot of turbo lag and it seems to lack torque once you build up a few revs. It pulls hard at 2000rpm but then tapers off a lot before the next gear change when accelerating hard, even with the 9 speed transmission.


The other issue with all the new LR diesels is having to use Add Blue. It must be refilled using a few 1.9l bottles costing $16 a bottle. The only ones I have found are at a dealer. None in any shops that I can find.


My first refill at about 4500km would have cost $150 but was free for the first fill. I am going to try buying a 1.9l bottle and then refilling from the 20l containers you can buy. According to the manual you can't use the Add Blue pump at the servo, which makes it very inconvenient, compared with say Audi which has a filler located next to the fuel filler to fill up from a servo.

DPF = Disabled Performance Filter, what a pain these are , might be worth a chat to Kevin about deleting it after the warranty , Pete Bell should have a software patch for it by then