But they’re both made by Honda! Haha. I’m reading into it… Apparently I wouldn’t be going what my speedometer says, and I’d probably not be able to brake! 10% difference and all that. I can dream.
Aside from the other problems (wrong size rims, etc), even if the tires were of the correct size, they do not have the correct load-bearing rating.
The “82” number for the Civic tires, and the “89” number for the Accord’s tires indicate drastically different load-bearing ability. Even if the size factor was appropriate, the Civic tires would be so severely overloaded with a car of the Accord’s weight that they would be in danger of blowouts within the first few miles being driven.
I suggest that the OP go to the Tire Rack website in order to learn more about what the numbers embossed on the tire sidewall indicate, as this info is very basic to vehicle safety, and not knowing this type of basic information will put the OP in possible danger in the future with other tire-related issues.
If the OP goes to this page on the Tire Rack site, he can begin his badly-needed education on the subject of tire ratings:
To know the size tires on the Accord, just look at the size on the tires that are on it. The important number to begin with is the ‘R’ number. This is the radius of the rim. Your Civic has 13-inch rims. The Accord calls for 15-inch rims. No way can you put a 13-inch tire on a 15 or 14 inch rim. And, a 13-inch rim will not fit over the brakes designed for a 15-inch rim clearance. Just will not work.