I did my first 0-50 test today, this was with a cold engine. Although cold being a relative term since it was 90 degrees outside. It took 7.6 seconds. Now that is probably at least 10% plus or minus since it's hard to stop the stopwatch at exactly 50 mph as I was only making brief glances at the speedometer, I think I actually stopped it at around 53 mph. But either way it does lean more towards having a higher number with a cold engine since the magazines are saying they did 0-60 in that same amount of time. Although to my surprise when the engine came on it was pretty loud, certainly not just idling, but no way to tell really how much power it might have been adding.
Any incline would of course affect the time but I think it was fairly flat, but that will wash out anyway as long as I do the hot engine tests at the exact same location. However I already know before I do any more tests I need to rig up a camera pointed at the dash because even though no cars were around I don't want to be driving with just one hand during hard acceleration, and also even though I wasn't looking at the stopwatch it is still distracting to keep glancing down at the speedometer. So I need to somehow get the stopwatch in the same shot as the speedometer, then start the stopwatch and have it already running when I do the 0-50 tests, then I can afterwards look at the video and simply subtract the starting time from the ending time. Not sure how soon I will get to that, so in the meantime I only have the one data point for whatever it is worth.