Gents,

I have the opportunity to purchase another P38. But it's a 4.0

I would prefer a 4.6, but I do really quite like this car, it's not perfect (but what P38 is now a days?). But it is in pretty decent condition, has a load of history, and will come with some extras that would definitely be worth it. Does need a few bits and pieces mind, but nothing huge (as far as I can tell, recent new compressor and airbags for example).

Anyway, is there anything in particular worthy of note on the 4.0's? Or should I hold of for a decent 4.6 to show up?

As far as I'm aware the shorter stroke 4.0 revs better & is marginally less likely to suffer from the dreaded slipped-liner syndrome.

I also suspect you won't notice a huge performance difference either. The 4.6 should be a bit more grunty and when running spot on and tuned has the potential to give more power.

But the reality is the 4.0 is rated at 182-187bhp (depending on where you read it, difference is likely some dodgy conversion from imperial to metric HP combined with ####ing about with DIN and SAE Net standards).

Either way, the 4.0 makes circa 45-47bhp/litre

The 4.6 isn't really a higher state of tune, just larger displacement. So assuming it has a similar specific output, then 4.6 x 45bhp = 207hp.

I know the listed figure for the 4.6 is 225bhp (or 221, again depending where you read it).

But in the USA Land Rover got taken to court and sued for the 4.6 not making the rated HP. They generally fell short of 200hp. LR recalled them and did intake, exhaust and ECU work to get the power up. However in the UK there was no such recall. So chances are, most/all UK spec 4.6's make nearer 200hp than 225.

All this means the performance difference between a 4.0 and 4.6 is likely not huge. The 4.6 due to it's displacement should make slightly more torque across the board.

You are right about the power variations, listed figures are very general. Conversely I had a totally standard 3.5 EFI that made 170 bhp on a rolling road, 5 more than the official figure & that's when the car had clocked 150k!

4.6 runs a bigger better auto box...thats for a reason...