Switching Michelin tires and interesting find about speedometer error/accuracy

For those that have followed along, I had a set of Michelin LTX A/T2 all-terrain tires mounted on brand new OEM 2021 4runner TRD Pro 17" wheels a few days after I bought the truck. I ordered and had the tires installed at a local Discount Tire. Driving home that first day with them and getting on the freeway I noticed a slight to moderate vibration in the steering wheel from 60-70mph. I went back to that same Discount Tire a few days later and they re-balanced them and said that nothing changed and they were all within ideal balance. A week or so later I had the dealership install the TRD Lift Kit and mentioned the balance issue to them. I had them road force balance the tires and they said they were out of balance but corrected them. It improved the vibration by maybe half but it was still there and noticeable at highway speeds; you could see the steering wheel vibrate when you released it on a steady smooth road at that speed.

At this point I was getting a little frustrated and just thought that maybe any all-terrain tire was supposed to behave like this. Discount Tire has a pretty liberal exchange policy so after coming home from a road trip to St. Louis and back I had them exchange the tires for the Michelin Defender LTX all-season tire in the same size (265/70/17) on the same wheels. I did go to a different location though. The tech there said the wheels/tires were pretty hard to balance and on two of them he had to use 4oz of weights to get them to balance. It was close enough to closing time that I couldn't really do too much. I drove immediately to the highway and got the truck up to 75mph and, voila, they were perfectly smooth and steady with absolutely zero vibration in the steering wheel under any condition. I am a bit concerned about the amount of weight they had to use to balance them (see picture) as it looks like a strip stacked on top of another strip inside the wheel. I'm sure it's safe and won't cause harm but certainly there is a better way, right?

Maybe next week I'll reach out to the shop locally they a lot of forum members do business with - Greer Automotive Services - as they seem to specialize in Toyota trucks and SUVs. I did some reading on properly balancing a wheel/tire and read that you should align a dot on the tire with a certain spot on the wheel or something.

Interestingly, with the all-season LTX Defender M/S, the digital speedometer is 100% accurate with the speed reading on both GPS navigation apps I use on my iPhone. I had my passenger tell me the exact second the speed changed on Waze and it was the exact second it changed on the speedometer. With the LTX A/T2 tires there was a half to full 1mph difference between the speedometer and Waze. I say half mph because at times the Waze reading would change then a second or two later the speedo would catch up if the speed increased ever so slightly. According to Tire Track, there is a 0.1" or so difference between the overall diameter of the Defender LTX and the LTX A/T2.

 

IMO, more weight is needed for AT tires. Def more than my passenger car tires.