As you have 20" wheels the recommended pressure is the same for the MPS4S as the P-Zeros - 36 PSI front and rear.
37 PSI is a tiny bit high and will make the ride a bit harder than it needs to be and could result in the centre of the tread wearing quicker than the edges.
I find 36 PSI a bit hard so I run 34 PSI with no reduction in grip or handling that I can detect.

 

 

The 2017 manual calls for 37 psi cold for all tire sizes. This applies regardless of brand unless you prefer to adjust it for other reasons like OzXFR mentioned.

From this page:

 

My tyre placard definitely says 36 PSI, so obviously the recommended tyre pressures were bumped up from 36 PSI to 37 PSI some time between MY 2015 and MY 2017.
No idea why JLR would do that, maybe the later OEM P-Zeros are different to the earlier versions?
I have been running the MPS4S at 34 PSI for 16 months now with zero problems (no pun intended honest Guv!), and no way on this Earth am I going to put them up to 37 PSI, I value my spinal health too much for that.
Funny thing is with VAP lowering springs and 34 PSI I expected the edges and especially the inside edges to wear a lot quicker than the rest of the tyre but that has not happened at all, just the tiniest bit of extra wear on the inside edges.

Also, on my old XFR with identical front tyres and only slightly smaller rear tyres (285/30/20) the recommended pressure was 34 PSI front and rear, and it's a significantly heavier car than the F-Type. So why the gradual creep of recommended tyre pressures?

 

Thank you all for your replies! I just wasn't sure if the MPS4 brand had a different PSI recommendation than the P-Zero's...although I'm finding out that the vehicle manufacturers PSI recommendation also applies to different tire brands. I had normal wear for the 18,000 miles I put on my P-Zeros running them at 37 cold. I'm looking forward to seeing how these new shoes feel and perform. Tire-Rack says it takes about 500 miles before new tires reach there break in time.
CRS

 

 

Same for MY18, too.

 

Keep in mind, if you measure cold and then push the car, tire pressures will increase.

 

Yeah, mine get up to 41 even in this cold weather.

 

Page 166 of the '14 Owners Handbook mentions that tire pressures need to be adjusted for ambient temps.

 

Yeah, already done that.

 

What is the feeling on starting pressures if using Nitrogen? Start at 39ish because the pressures are much more flat when warm? I am making the assumption that the real warm operating pressures are in the 39-41 range?

 

Virtually no difference among the gases (PV=nRT), especially since Air is ~80% Nitrogen. The variable, of course is the moisture content of the compressed air, but if compressed at these cold temperatures, not much of a factor either since it'll be relatively dry.

 

 

They take forever to lose pressure. Instead of dropping 1psi or so per month, you might lose that much over the course of 4-5 months with nitrogen.

For most people that means slightly better fuel mileage if they're the type to wait until the low pressure light came on to do anything about it.

 

The Pzero were too hard at 37 psi so I had them on 34. The PS4S are perfect at 37 cold and up to 43-44 hot.

People talk very badly about the Pzero here but I really liked their direct touch. The Michelin are too soft until they get warm.

 

Thanks again everyone :-)
Update: Definitely a nicer ride overall with everyday driving and very responsive. They seem quieter than the P-Zero's, but I'll need to do more highway cruising to judge. When the weather dries out and the twisty canyon roads become a bit safer, (lots of falling debris..mud and large rocks due to recent fires) I'll be able to get a better feel for the tires over all. My understanding is that it takes around 500 miles for the tires to break in.
Cheers
CRS