WMN:

Great torque and power curves .. thanks for sharing those. Really cool.

The P300 reaches its max flat torque at 1500 rpm, which is 500 rpm sooner than the P400.

It is that 500 rpm which I have noticed as so valuable when off-road. 1500 rpm is really light on the throttle -- and the torque is fully there and stays flat as the power comes up to what is a practiced maximum of 3000 rpm (up to 4500 rpm per the curve, but I never go that high off-road). When I push through 2000 rpm, I only do so if I am stuck -- and want to clear heavy snow, mud, sand -- or if I am through the sensitive grip portion of the obstacle and want to go faster.

Because there is no jump in grip/slip caused by the engine torque curve, the logic of the TR2 and my driving do not have to correct at all for the change in torque mid-obstacle.

Enjoy!

 

This is the comparison. The P400 makes significantly more torque and power at all engine speeds. I cannot see that the P300 has any advantage at all, especially since it doesn't even win on fuel economy.

 

I think is not a contest -- different designs for different purposes. Clearly, for aggressive driving on-road the P400 is preferred.

In my P300, I do not count on an ability to accelerate aggressively above 75 mph. But, I do not need to since I live in the sticks -- and I don't rush and drive fast anymore, anyway (hey, it happens!)

Off-road, the fact that the P300 reaches flat torque 500 rpms sooner makes it a better fit. TR2 needs steady torque and control over the transmission to operate as perfectly as it does, I think. As slow as possible, as fast as necessary.

I retain a couple of V8 5.0L LR4s to use in towing 7300 lbs. -- so all good there.

Trade-offs.

Enjoy !

 

But you have to also acknowledge that the P400 is already making more torque than the P300 max torque at less than 1500 rpm. The plots above highlight this.

 

I think we're about 90% in agreement, except that I take issue with the limited statement in bold. I don't think that's the only place where the L6 shines. You can very well enjoy it without "aggressive" driving.

As our 7-people mover/family truckster complete with occasional towing ability, CARRYING ability (see my thread with the Ducati hanging on the hitch carrier), all weather commuter, it excels across the board.

Actually it accel's too, and very well without needing to be aggressive.

I'm very glad we had it built this way as it matches our uses presumably much better than the 2.0.

And I'm a bit of proponent of "better to have it and not need it, than the need it and not have it."

THAT SAID, I could see myself in a D90 2.0 18" wheels as such a configuration would likely be more than I need. The torque curve is certainly beautiful and I can see how well it must work, especially off-road coupled with some of the goodies that are available on this platform.

But what do I know, my "daily" being a < 300 hp, 6-speed, archaic in comparison Jeep Wrangler Unlimited which is not particularly great at anything more/less than putting quite the smile on my face every single time I drive it. Which I guess is all that matters to any of us at the end of the day.

 

Just to be completely clear - those curves are maximum torque. The engines can deliver lower torques at any engine speed, and a flat torque curve is only important in providing enough torque across the band. A higher curve per se doesn't have any negative implication for smoothness of torque delivery.

 

Muppetry:

This is interesting.

Off-road, how effectively could TR2 map the delivery of varying torque amounts from the engine into the transmission and then to the individual wheels, if the torque varies with engine speeds AT THE SAME FUEL FLOW RATE ? I put in a correction here because I should have written it before. Sorry.

I think the revolutionary effectiveness of TR2's mapping logic depends on a consistent amount of torque being delivered at same fuel flow rate and rpms. This means transmission shifting must always be automatic, as well as what I also described here, below. Said another way, when you are stuck, make sure you place the transmission in either S or D -- not selected S gears.

My experience to date with the P300 and TR2 is that under 1500 rpms, at a dead stop, as the driver presses the throttle, TR2 only allows fuel into the engine at a rate suitable for the TR2 logic to deliver the increasing torque in a very controlled fashion (to not spin any wheel excessively). If it is unable to do this, it switches to "launch control" mapping logic, which takes over the throttle completely (without necessarily telling the driver) and varies torque available with RPMs. Often launch control below 1500 rpms does not work, because I think the logic is very limited when torque is varying with RPMs.

Below 1500 rpms, TR2 seems to actively do little to optimize the distribution of the torque to the 4 wheels using either: the fast braking limiting wheel spin or the "clutches" in the two differentials activating (other than when one is certain conditions -- like when towing from a dead stop the rear locker is on full immediately).

However, once 1500 rpms is met, and beyond, the activity level of these two capabilities jumps markedly. TR2 seems to come to life in a moment.

Through trial and error, as a rough guide, I have found what works in getting unstruck is to be in either S or D (it does matter which), select the correct TR2 mode and have DSC in the correct postion, and then take the RPMs to 1250 -- and then slowly by even steps increase by 100 rpms (even as the wheels spin) until it reaches 3000 rpms (3500 when I really get aggressive and really want the vehicle to move.) By doing this vehicle will be moving ... or it is not going to move.

This approach seems to work really well.

 

But your experience with TR2 is what it is because you’re driving a P300! Have you properly experienced TR2 in a P400, which is already delivering more torque than the P300 by 1500 rpm? Or considered the possibility that JLR engineers understand better than anyone the differences between their own vehicles, and if there needed to be engine-specific adjustments would have done so. You’re implying that TR2 is optimized for the P300 - and that’s most likely not the case. More likely is that TR2 is optimized for each application.

 

I've put 3,800 miles on my 2022 p300 with 18's and recently drove a 2020 p400 with 20's for a few days while LR performed my first oil change.

Towing - Towed my 6,000 pound Grady White with no issues what so ever with the p300

Driving Feel - In my opinion the p300 on 18's is a much more luxury driving experience (the 18's have something, but not all, to do with this). The shifts are smoother and the power delivery is more linear. It appears it is a better match to the transmission. Feels a bit lighter.

Driving performance - around town, I think the p300 is more zippy. On the highway, especially trying to pass from 55/ 60 to 80, the p400 is much better.

Over all, I chose the p300 to keep my build at 65k vs 75k. After driving the p400 I don't regret the decision.

 

interesting you’re mirroring my experience to the T.

What did you notice about the P400 with regards to lack of linearity ? I expected the 2.0 to have turbo lag etc but it seems like the lag was isolated to the 3.0