NHTSA Complaint #11486937 — 2020 GMC SIERRA 3500

I had a blow out on my rear tire on my 2020 GMC Sierra 3500 AT4 truck while travelling down the highway while pulling my 43 foot RV fifth wheel toy hauler. The vehicle had 21,000 miles on it. The tires and wheels are Goodyear Wrangler LT275/65R20 E rated tires. The problem is i changed the tire to find i had a a MICHEllin LT 275/70R18 tire for a spare that i changed. This effected the ABS and was hard pulling my RV back home for another 40 miles. Under NHTSA Campaign number 21V578000 GM recall number N212329780 there was an issue with the spare tire in the sierra 1500 and 2500 trucks but not mentioned in the 3500. This was a huge safety issue for us to pull the truck home as we had to drive at 35 mph for 40 miles on the highway. GM should not be putting a smaller tire/wheel as a spare on a large truck. One side is significanlty lower than the other when the two different tires are on the back of the vehicle.