Standing Water on Motorway

[anorak]

My GTR was well over 2 tonnes it's not about weight it's the tyres

Pretty sure it's about weight and tyres, amongst other factors. Ever driven a Caterham in the wet? Bridgestone's website concurs;

Hydroplaning is caused by a combination of speed, road conditions and tire design and condition. Let’s take a deeper look at all of them:

Water Depth/Road Conditions - As water depths on the road surface increase to more than 1/10th of an inch, the risk of hydroplaning grows exponentially. Both the intensity of the rainfall and type of road surface (for example, asphalt vs. unpaved) play a substantial role in creating hazardous conditions.
Vehicle Speed - A tire’s tread needs time to evacuate water from under the footprint and the higher the speed, the less time is available for that to happen. Depending on the condition of the tires, their design and the amount of water on the road, hydroplaning can occur at speeds as low as 45 mph.
Tread Design - All else being equal, a tire with a wider tread facing the direction of travel will hydroplane sooner than one which is narrower. The wider footprint has more surface area to form the wedge of water at its leading edge.
Tread Depth - Of all the factors which contribute to hydroplaning (or to resisting it), the tire’s tread depth is among the most critical. Even high-quality tires will have little resistance to hydroplaning when worn to 2/32” or less, so it is vital that worn tires are replaced promptly for safe driving on wet roads.
Vehicle Weight - If we compare two vehicles equipped with the same size and type of tire, the heavier vehicle will have an advantage in resisting hydroplaning because there's greater force to displace water from under the tire’s footprint.

And at "well over 2 tonnes" what had you done to your GT-R? Nissan quote a weight of 1752kg.

Did it have an aftermarket 40kWh battery pack fitted?

[electric beagle]

Alright almost 2 tons (or circa 1814 kg) but I don't think weight or tyre size were dramatically different compared to the iPace the tread depth almost certainly is though.

The problem I had was that an otherwise empty motorway had one patch that was seriously flooded to a fairly deep level during a flash flood, there was no real warning until t he spin had started, I hit it as soon as I saw it and probably an attempt to brake hard would have made things worse.

You can't go round driving at <45MPH all the time "just in case"

[anorak]

Completely agree and I'm glad you're still around to talk about your experience. Completely losing all steering feel at high speed is terrifying.

My point was just that the OP's question was whether we thought the weight of the i-Pace had any bearing on its stability going through standing water, which it does.

I'm not saying it won't ever aquaplane, all cars will given enough speed and water, just that it is less prone to it than their 5 Series or E Class were, mainly due to weight and possibly tyre width.