In my case, the car without ACC is an RV and since driving it is like trying to push a small house through the air, it responds pretty quickly to speed reductio

In my case, the car without ACC is an RV and since driving it is like trying to push a small house through the air, it responds pretty quickly to speed reductions. Plus I tend to keep a pretty long distance from the car in front of me, so I have more time to respond. I like to pick a truck to pace behind since a lot of people don't want to get stuck behind a truck so they don't pass me then pull in behind the truck, even with 5 or 10 seconds of following distance. Another advantage of pacing a truck is that they usually keep a pretty steady speed unless they are going up a hill, but then on the hill I can usually find a truck that's light enough to keep a pretty steady speed uphill.