It’s a dilemma: Do you set your maximum cruise control speed higher than your maximum accelerator speed?
We know of at least one fleet that sets its cruise speed 3MPH faster than his foot throttle speed. He does this primarily to promote the increased use of cruise control, which leads to improved fuel economy. It also promotes keeping the truck in overdrive of the highest gear to reduce RPMs and increase MPG.
There is a lot of talk in the industry about if it is unsafe for a driver to spend too much time in cruise. The concern is that drivers using cruise will get drowsy. The good news is that collision mitigation technology can play a big role in mitigating that risk. Most early versions of these systems are only active when the vehicle is in cruise control. Newer versions and soon to be released models may make the system active either in cruise or foot throttle mode, but for the most part, collision mitigation systems on the road today only work when cruise is active.
Like with many issues relating to improving fuel efficiency there is not one answer on how a fleet determines to set its maximum speed limits or whether they set different speeds for cruise and throttle. Each fleet must examine its operation including evaluating its drivers before deciding which strategy makes sense for them. The goal of course is to be both and fuel efficient.
These benefits and consequences of how to set speed is exactly why NACFE has decided to complete a Confidence Report on this subject. Contact me if you have comments on it.