The digital gauges have one drawback..the information they are capable of showing is actually too detailed. A couple of aspects to consider:
So far here, we are comparing Maximum Peak numbers, seen for very short periods, with less emphasis on true average temps. An analog gauge would be hard pressed to show these transient peak temperatures. It's very important to understand the difference between average and peak in this instance. And no...a stock Sol will never have to dissipate the heat load peaks that 275HP creates, so it will never see these peaks.
If we had regular analog gauges on these cars (as they should have had, in my humble opinion!), with a typical range of 0-250 degrees, this peak difference would be largely unnoticeable...consider how much gauge movement 5-10 degrees is out of a 250. We're talking like 2-4%, virtually imperceptible on a gauge 1.5" in diameter.
Engine temperatures in the 200+ range are typical in these times for efficiency. An 'overheat' condition doesn't exist until engine temperatures climb into unsafe regions and just keep on going...like 230-240-250, now the pressure cap vents, and we have a true overheat. An occasional foray into the high teens on your digital gauge is no cause for alarm, it's just showing that the boosted power you just made put a 'heat wave' into the coolant, and now that hotter coolant will make its way to the radiator for processing. The fact that he cooling system arrests the rise and brings the temperature back down is really all you need to know...it's doing its job famously, and reacting as it should to the temperature rise.
Now, all this is not to suggest that the turbocharged car does not create more heat than the stock Sol...to suggest such would be ludicrous! Any time we make more power, more heat is created. It's simple physics, and it doesn't matter whether it's a turbo, or a supercharger, or even Nitrous or a larger engine. The overriding concern is...does the additional heat load strain the cooling system's ability to control it, or even worse, create an overheat situation? I'd have to say that so far, we've seen some pretty brutal midsummer conditions, and the turbo Sol's have come through it rather well!