Update.
From an automotive Engine and Transmission industry expert with pre Ingenium direct experience in design and supplying LR.
His Comment. I haven't found any direct contacts, but had a few discussions with colleagues, and no one thinks there's any issue. The transmission is the same, braking, towing and suspension specs the same,

My comment.
The towing capacity, 3500kg, for D250, D300 and D350 is exactly the same. That has helped me get a lot more comfort when laying on top.of the comments above.

I'm going to check the fan/cooling point.

Again. No expert, just trying to step through unpicking the c16% increase in power being pushed through the original spec.

Exactly what I was saying, however, the RRS D250-D300 has a mass of 2390 kg and the D350 of 2435 kg. The RR in all versions has 2455 kg. I think it's a mistake with the RRS. I can't find the service manual

Click image to enlarge

Click image to enlarge

In the RRS, the D350 is only available in Autobiography spec (on the UK website currently). AB spec has more stuff as standard e.g. sliding pano roof, more seat motors, etc., which all adds to the base mass. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

The conclusion would be that the engines are identical, right?

Suspect this would affect already high insurance as it is a ‘power’ model dedication?

Re Insurance. No impact on my new policy at £1100 per annum fully comp with commuting included.
I am in the sticks though....

However, some insurers will not even accept modifications as I discovered in my research.

Update.
Today I tried, tested and had the bonnet up on a 23 Plate D350 Autobiography next to my 23 plate D300.
The physical components in the engine bay are exactly the same.
Obviously that does not rule out things that I could not see.

Drive. I drove the same route with them both in Dynamic. Put the same demands on them.

Conclusion. I would say for £495 it was worth the upgrade. But that is just my view.

Now to find the most reliable supplier.
Low to hear others feedback on the change in performance.

Thanks.

Got this back from Venture Automotive ,
Something must have made them pull it from the market?

 2024 Range Rover Sport D300 Dynamic SE in Varesine Blue
2019 Mercedes E Class Estate E350d (Gone)
2017 Mercedes C43 Cabriolet
2013 Jaguar XF Estate 3.0d (Gone)
2016 Mercedes CLA Estate 220d (Gone)
2006 Range Rover Sport 4.2 Supercharged (Gone)

Very interesting. Thank you for sharing. I was literally speaking to them on the phone trying to book in this week. Not been possible.....

Will update when I'm clear.

Have you considered anyone else?

Tried these guys but they never got back to me:

https://projectrebel.co.uk/

The folk I put on the 1st thread are miles away and will only do the service locally to them and sounds like they don’t have a workshop, probably one man band, hence my hesitation.

Think I am going to sit on my hands. I feel fate is trying to tell me something!

Surprised there aren’t any forum sponsors on here that could put our minds at rest who offer these activations. 2024 Range Rover Sport D300 Dynamic SE in Varesine Blue
2019 Mercedes E Class Estate E350d (Gone)
2017 Mercedes C43 Cabriolet
2013 Jaguar XF Estate 3.0d (Gone)
2016 Mercedes CLA Estate 220d (Gone)
2006 Range Rover Sport 4.2 Supercharged (Gone)

Agreed....I will keep you posted on anything I discover over the coming weeks.


I did DM the other forum member that used venture automotive but he never got.back to me.

Thx

Going to refresh this discussion
I'd been looking at https://lr-retrofits.co.uk/l494-sport
They claim it's more than just a remap but then for £500 I can't see there being the budget for many parts like a new radiator.
I'm also curious whether there's any economy benefits of going from 300 to 350 - I assume not given the 300 isn't exactly struggling for power in the first place, but maybe off the line it can change up earlier? 2021 L494 D300MHEV Autobiography
2019 Discovery Sport D180 HSE

Last edited by 41jules1967 on Fri Aug 08 2025 9:09am. Edited 1 time in total

Duplicate 2021 L494 D300MHEV Autobiography
2019 Discovery Sport D180 HSE

I was getting a few activations done by this guy https://www.lr-chip.co.uk/ and I was chatting to him about the difference between the d300 and d350 engines as he too offers the power upgrade. He said they checked out all the part numbers for both engines and the only difference was the injectors are a different make on the d350. However he then checked out the specs for both sets of injectors and the pressure range was the same on the d300 injectors as it was on the d350 and so should handle the power being turned up. MY24 Dynamic SE,MY21 HSE Silver, MY20 SQ7, MY 18 RRS HSE Dynamic , MY 16 RRS Autobiography now gone & MY 2005 Discovery 3 HSE that I will be buried in !