That's a good point. If the car goes up to 220 and STAYS there, that's not such a terrible situation but in our experience, it's very rare that a car stabilizes at idle in that 220 range. The more likely scenario is that it will continue to creep the longer the car sits. I was not a happy camper at 220. when I saw it creeping to 225 and then 230 etc. nobody is going to be having any fun driving under those circumstances.