Back when I was driving the big trucks it was by the weight.... ( class) we used to run heavy and when pulling our rigs onto the scale ( each lane has one) we would skuff our tires on the curb , that would lower our weight just enough to get back down to class 7.... From 8... 8 is 80,001# to 100,000# and 7 stopped right at 80,000#
It will be expensive to run from Ohio to Harrisburg... That's about 250 miles... When pulling my trailer , i forgot our ez pass and had to pay cash on a trio from NE Philly to Hershey.... That 60-70 mile trip on the pike was almost $20.00
On edit - I was just on
Pa turnpike.com. ... For some reason I am un able to copy and paste.... On page 2 it states that your trip on the PAPike may be determined by either axles OR weight.. OR BOTH.... Read more , it has 50 pages for your reading pleasure!!!
Here-- per the site ---
Current Toll:
Your Cash Toll Amount will be $69.45
Class-4 Ticket Toll: $52.00
4-Axle Toll: $17.45, at the Gateway Toll Plaza - Eastbound
Your E-Z Pass Toll Amount will be $49.67
Class-4 Toll: $37.25
4-Axle Toll: $12.42, at the Gateway Toll Plaza - Eastbound
You save $19.78 by using E-ZPass on this trip
That's for class 4 ( 19,000. -30,000) and 4 axles ... From Ohio to Harrisburg East