That for me would also mean less basal insulin required, in my experience the strength of the insulin doesn't change, it's the strength of your reaction. When I took Lantus I needed less when it was very warm and weirdly less when it was very cold (no idea why). The biggest sign for me that I needed to go down a unit was what I called a flatline. I'd take the normal ratio for food but two hours after it would be exactly the same as the pre meal reading. That's not too much of a problem, but then if I ignored it I'd start to get hypos. That said, basal is always my problem, the bolus is very well behaved 🙂 On injections it may be less of an issue, providing you're not getting bigger spikes from the food at an earlier point. The rapid is meant to help iron out the peaks from food that a slow acting basal can't. So I could take more basal than I do now and still have great premeal numbers but I'd have a spike between times because I'd have to take less rapid. If I take less rapid then it only deals with some of the spike and the basal drips it back down. Since I'd prefer not to have the spike my management strategy is to down the basal and keep the ratios for rapid at the level that irons out the spike. So it depends on your management strategy I suppose, oh and how much slow release carb you eat too. If you like a lot of slow release food then the consequence of that is generally more basal insulin because your food is "dripping" into your blood stream, and then less rapid is needed to iron out the spike because the spike is smaller. BTW I'm totally jealous that your basal has been stable for 2 years, mine struggles to stay stable for 2 months 🙂