It time to change out my stock tyres and am wondering if any one went wider than our specified sizes. I didn't get the width recorded down and am uncertain of the max width my stock 19" rims can correctly handle.
Current sizes are: 225/40 & 255/35
Hoping to go 235 & 265, if possible.

If you have an AWD model I would stick to the same size. Why not just buy better tires at the same size as OEM? You know there will be no issue. Why give JLR an in on voiding a warranty issue because you did not replace with the correct size; warranted or not?

Stay away from Pirelli tires. Had my car for just over one year and I've had to replace a tire twice for bubbles in the side wall. We do have pot holes here but I'm usually very careful and in all my years of driving (50+) I never had this problem. One more bubble and I going to try to switch over to another brand Like Michelin or Conti.
My 911 had Pirelli P zero and I never had this problem

I would say stay away from the Pirelli Cintaurato that came with the XE. I am less that 10K miles on my car and am on the 6th tire. Thank the Lord for Rim/Tire insurance! I like the P Zero Nero line from Pirelli. Had them on a few cars and never had the bubble and all that like the Cintaurato. There's plenty of tires out there to choose from and a real high performance tire will transform this car!

It's nothing too specific in my changing of the tyre's width, maybe that tad more grip when needed? For now, I'll still be sticking the the original front's 225/40(front rims aren't wide enough) and 265/35 for the rear.
I am on Dunlops for now, stock and they are pretty much a nightmare to use. After having 2 close shaves, I am changing them out even though they remain usable(14k km till date). --Off topic here, but the production dates of my tyres given are a joke! 4tyres, 3 different dates and they are STOCK from JLR!

Anyway, had been using Pzeros( Neros, Rossos & Pzeros) for my previous cars , no Cintauratos for sure, and I did not encounter any issues with them. Given that, I will be going Pzeros next. Just waiting for price and stock before new shoes go on.

Oh, Im the RWD model.

P Zeros have served me well. They are well priced to boot! I would say consider Bridgestone's top performers and also competitively priced. The Dunlops that came on my XK were fine tires, but you needed a banker's mint to replace them. Very few owners kept with Dunlops when came time to replace.

If cost is no concern, go Michelin

If you won’t bang for the buck, Continental makes an amazing tire for 20 percent less. I’ll be going to Conti when make stock gives up the ghost.

Eventually, I went with Michelin's PS4S due to lack of size for my rear from Pzero's new thread pattern. Final tyre profiles on my XE are with Michelin's PS4S 235/35R19 and 265/30R19.

The first driving feel from this set of tyres is pretty satisfying. They are more comfortable to drive with, when compared to stock Dunlops, even thought PS4S comes with a slightly thinner profile. Although being a short drive back, evidently, the drive is more stable on straights and in bends. Grip wise, I can definitely feel the difference as I'd to accelerate that bit more to get the car going but also the depression of brake pedal has lessened as well.

All in all, I think this is making out to be a nice set of tyres to use and the durability test begins now...!

A buddy just got them installed on the his Benz and likes them a lot.

Yesterday my wife hit a curb with her new XE-S. Only going 2-3 MPH (so she says). It destroyed the sidewall of the Pirelli Cinturato P-7.There is only about 1000 miles on these tires.
None are available locally so she will be a few days driving on the orange rimmed spare she hates...
We will be looking for something more durable next time.