There is a little sticker on the side of my truck that says I have a 400-pound weight exemption because I have an APU (Auxiliary Power Unit) installed. My question has always been whether this was just for gross weight or whether that pertains to axle weight also?

In other words, am I legal at both 80,400 pounds gross and 34,400 on the drive tires? In the past, the peeps at my company had no clue. Well, I finally got to the person who had the answer. Well, sort of.

Now many of you may already know what the deal is here, but I am going to go on the assumption that if I had a question about this issue, there are probably other truckers out there who have the same question.

The short answer is yes, the APU exemption pertains to both gross and axle weights. But it’s not quite that cut and dry. According to an OOIDA article, the problem is that this federal law is not “mandated,” meaning the individual states can do whatever the heck they want to. And when the states get that right, they often use it. In short, some states have a 400-pound exemption and some have a 550-pound exemption, while others still haven’t made a decision yet. Some are enforced by law. Some are at listed as “by enforcement policy rather than by law,” whatever the heck that means. Not good.

Now for the most part I think state’s rights are a good thing, yet when it comes to something like trucking, which is an interstate thing, there needs to be a common rule. But since I’m not a legislator and I would rather have my foot run over by a fully-loaded semi than ever be one, there’s not much I can do about it.