Ohhh that experiment is even better! But sounds like a darn lot of work though, but it would be great data.
I'm not sure if that 7% holds up with all the gear ratios though. I remember with gears driving gears, sometimes a logical thought like 7% wouldn't be true, but I could be wrong it's been a long time since I studied them. But either way you aren't going to trash your tranny by going a little bit larger in the sidewall. Just stay away from the 225/80/16 touring tires, that may be a bit much