Master
I've been poring over every tidbit related to the new Defender for the last couple of years, and I pretty much settled on what I would order – a D240 110 SE with some essential extras would do great for many thousands of km of rough roads and tricky tracks exploring the country. I'm not a caravan kind of guy but could see myself taking an Opus 2 or something light like that on longer trips with my wife.
Now Land Rover Australia has got me in a serious pickle with the MY21 changes. No more four-cylinder diesels coming our way, and some major caveats on the six-cylinder models that replace them:
- SE's minimum engine is D300, which doesn't permit 18" rims
- They are mild hybrids, which means they have batteries and stuff taking up room I'd like to use beneath the rear luggage floor
- Worst of all, these engines don't come with a centre diff any more!
Instead of a centre diff, the rear drive shaft is rigidly attached to the transfer case output while the front shaft gets drive through a variable clutch pack. This combines with another clutch on the front right half shaft to permit the front drive shaft and crown gear in the front diff to spin down completely when front drive isn't needed – it's claimed to improve fuel economy by 1.7%. But I'm nervous about what compromises it might involve for off-road use, and not keen to be among the very first customers for LR's new drivetrain experiment. Maybe it'll be awesome and super reliable (it is just a clutch pack after all) but nobody knows if it's actually *good* yet.
18" wheels are non-negotiable for me, so the options on the table are the D250 diesel six or the P300 petrol four in an S spec. The P300 avoids DPF, EGR and AdBlue. It has a ~90L fuel tank and is claimed to return the same L/100 as the larger diesel. It's lighter. It's not a hybrid of any kind, so maximum rear space is available under the floor. And it has the locking centre diff that we all know and trust.
In the D250's favour, it's a diesel and it has more torque.
Anybody want to talk me out of ordering a petrol Defender for exploring the unpaved country?
Swaggie
So thats two clutch packs to replace an electric centre diff.More complications,and possibly expensive repairs.Originally Posted by TB
Yet in their current range,centre diffs seem very reliable.
It didn't take much to talk me out of one,i don't want to be doing the guinea pig testing for LR,i have done enough of that over the years.
Master
I'm not actually worried about the reliability of the clutches – the electronic locking diffs are all implemented using clutch packs and I've not heard of one of those failing. My concern is more about how it behaves as a differential to distribute torque both front and rear when all wheels have good traction but you're in a turn. Something has to slip.
Swaggie
Really hard to know without a lot more info.
I am no engineer,but I am sure LR would have that sorted.
Just my 2 cents worth.
Swaggie
I like that constant 4wd with open diffs allocating torque assists cornering on sealed surfaces. With front wheels travelling further than the rears through corners I cannot see how clutches in the drive to the front wheels can make the front wheels turn faster than the rears and therefore cannot assist unless the rears slip. The clutches in the centre and rear diff if an e-diff only come into play when wheels begin to slip or as a preventative to slipping rather than providing normal drive.
The extra weight of the batteries and the space they occupy for such little reward when touring would have me looking for a way to remove them.
MY21.5 L405 D350 Vogue SE with 19s. Produce LLAMS for LR/RR, Jeep GC/Dodge Ram
VK2HFG and APRS W1 digi, RTK base station using LoRa
Master
I could be confused and mistaken about this, but I think that in at least one of the new engines (P400 or D250/D300) the electric motor for the mild hybrid system is also the starter motor. The MHEV stuff is pretty deeply integrated into the design and I can imagine any attempt to remove the electronics from the boot being something of a problem.
Swaggie
I suspect likewise and would do my best to avoid vehicles with such features.
MY21.5 L405 D350 Vogue SE with 19s. Produce LLAMS for LR/RR, Jeep GC/Dodge Ram
VK2HFG and APRS W1 digi, RTK base station using LoRa
Master
Just thinking really hard about the diff v clutch thing for the front drive... it seems impossible that the LR engineers didn't think about the need for the front to go faster than the rear. So what if they took that into account and actually overdrive the front? You could calculate from your minimum turning radius what the relative speeds need to be, then build that into either the TC or the front diff.
That would be a rear-wheel-drive system with on-demand recruitment of the front wheels when seemingly needed, but not for too long because the clutch slip would generate heat even when driving in a straight line.
I don't get it. Everything about this new system sounds dumb, especially for the engine and vehicle it's been deployed in. Really hope I'm missing something.
Swaggie
That the e-diff is optional indicates the market that LR is targeting.
The disconnecting front drive may make the front smoother until the front tail-shaft has to suddenly spin-up as the clutches engage. Backlash in the centre diff would be gone though.
MY21.5 L405 D350 Vogue SE with 19s. Produce LLAMS for LR/RR, Jeep GC/Dodge Ram
VK2HFG and APRS W1 digi, RTK base station using LoRa
Fossicker
My understanding of the new system is that the vehicle during normal operation is 100% rear wheel drive with the front axle / drive shafts completely disconnected. The front axle only engages via the clutch packs when the TC system detects loss of traction.
I was annoyed when JLR announced the new engines so soon, but am not regretting purchasing a D240. I think the MHEV just adds additional complications and points of failure with little benefit and the front axle disconnect is purely to reduce emissions and is not being introduced into the P300 or P400 vehicles.
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