This is exactly how Budget, Ryder, etc.... can rent joe blow a 5 ton straight truck. They register them for well under the GVW.
Just a quick note here, in my state the rules are sneaky for anything with a combined GVW of up to 26,000lbs (no CDL needed if juice brakes)----yes truck and trailer, and more so if 10,001 and up. If you cross the line and go 26,001 then CDL---regardless of air or juice brakes, so watch out you guys with the Ford F550 Pickup pulling a 9 ton tag trailer with say a Bobcat and small roller----you will be over 26,001---and getting grounded/towed---if you don't have a CDL...
I own a GMC 6500 (baby cat, Allison Auto)---door sticker says 18,000 Rear Axle, 10,000 Front Axle----naturally you would think 28,000, so CDL right? Nope, derated by manufacturer to say 26,000! My truck was a former Moving truck originally from Maryland. If I put a homemade trailer on it with a GVW of 1 lb---CDL, because you cross 26001. I tow a 9 ton trailer with it so my combined is 44,000---so Class A (formerly called Class 1), Combination License required---which I have (and a bunch of other endorsements) so they get me for about $130 every few years to renew!! I'm telling you guys, follow the max fines/rules and you will be in the clear!!
So back to the rental yard, under 26,000 is where they reside. I call it the gray area... If you rent a 5 ton truck, no trailer, no worries. Put a small trailer on it, then you need a health card and safety gear, you are over 10,001---by my States rules. Whatever you do, don't put a big trailer on it and cross 26,001----if you don't have a CDL---cause you need one to do that.
Anyone here ever drive by a weigh station and see some poor soul unloading a uhaul box truck? I have, LoL! First of all, if you don't have a CDL, don't worry about it, and blow by them. Plead ignorance with the Troopers----shoot, let your wife drive---works like a charm!! If you have a CDL, don't overload your truck, you know the deal, a commercial truck must pull in and get weighed regardless of who the actual owner is, its the drivers responsibility. Oh and you better have triangles, a chock block, fuses, etc---your safety gear.
Good luck gents!!