Does anyone have info whether the DC/DC issues have been addressed with 2026 models? If not, I'm reluctantly considering a compromise and get the P300 instead as a daily (mostly highway) driver. It's time to let go of my 2012 LR4 (190k miles).

 

P300 wont get DC-DC or exhaust manifold bolts problems for sure.

Electronic MHEV components failures are weird these days, ask Audi owners.

 

While the people at JLR that know definitively which VIN was the first to receive the updated converter assembly likely aren't on this forum, based on the anecdotal data we have it seems that MY26 units built after some day in January exclusively have the updated component. If anyone knows the physical difference in markings / labels on the revised part this group could determine the answer.

 

What makes you think there is an "updated" DC-DC converter component ?

This would suggest that while this failure is very annoying, it 'should' not happen again...ever?

 

While I do not have any insider knowledge on what updates, if any, the subcontractor who produces the DC-DC converter may have made in response to the failure of what I'd guess is a couple thousand of their systems worldwide in the past 24 months, it's reasonable to assume that JLR engineering management poked them hard in the chest and required detailed failure analysis along with a get-well-plan prior to ordering the next production block of however many hundreds or thousands of converter subsystems. The exception to this would be if the engineering failure analysis revealed that the failure was 100% caused by faulty integration into the Defender to include associated software, in which case JLR engineering is potentially at fault. I haven't kept up on how much of the failure analysis has been leaked or shared with the customer base and/or if any independent source has done their own assessment and put it on YouTube ect.

 

Do not be reluctant with the P300. I have owned all three engines and the P300 is my favorite. Nothing wrong with the 6 or 8 cylinder engines, they are both great but I personally prefer the 4 cylinder for its very linear acceleration and lighter weight. It is also great off road. Just my 2 cents worth...

 

Be aware that a P300 110 does not use the same engine as the P300 130 which also uses the inline 6 turbo, just tuned to lower output from the "P400" trim. Same exact engine though as the P400.
So, a sweet spot for ordering is a 130 P300, gets you the turbo inline 6, but around 300 hp vs 400, and then you can still option it identically, and keep total price around $85k for a new 2026.
Then simply use the GAP tool to map it like the P400 tuning.

Of course the P300 130 will be a MHEV though. in case that's something one is trying to avoid.

 

Personally, 16 months ago I walked into the dealership with the firm intention of buying the P400.

However, prior to purchase, my searches had me find that the P300 was the most recommended model due to it not behing a mild hybrid and therefore more reliable long term because of less things that could fail.

So to get the P300 out of the way, I decided to test drive it first… my findings was that it was pretty quiet and more powerful than the 3.6L 6 cylinder Jeep wrangler JLU that I was trading-in for it.

I then test drove the P400 and my findings were that it was noticeably louder, taking away the luxurious feel of the Defender, and there was an annoying dead zone upon acceleration that reminded me of an annoyance I had with my ex’s Audi Q5. Like the engine needs a second to think about accelerating when you want it to.

Upon returning from the P400 test drive, I asked to drive the P300 again to really compare the feel. Not totally convinced, because I was dead set on a P400, I asked to drive a different P400 which ended up exactly like the first one. So I decided to go ahead and get the P300.

What I’m getting at is that in my mind, the P300 is certainly not a compromise, but more of an option that I chose for reliability and comfort. Had to that the fact that I towed an enclosed trailer (6’x10’) containing a motocycle over 400 miles and the P300 towed this thing as if it wasn’t there.

With the money I saved, I got the whole xplorer pack and trailer hitch. And don’t forget that the P300 has 4.10 axle gearing rather than 3.55 like the P400 which explains why it is as quick as it is despite having 100hp less.