Thanks. Good information.
Running 80 in the V6 takes about 1/3 throttle with 275/60-15 rear. These tires diameter is 6.5% higher than stock 215/65- /235/60-15. Running 85 in the V6 takes about 1/3 throttle with stock rear.
My dog is stock, using synth. 10W60 + STP.
With stock tires in 4th+blocked my doggy runs 2560 at 80 and 2720 at 85.
Running 80 on 275/60-15 rear is about 28 (best; with AC at 1/2, windows and tops closed; 64°C; high humidity; 2 pers & trunk full; 91 gas)
Running 85 on stock rear is about 30 (best; with AC full, windows and tops closed; 100°F; low humidity; 1 person; 1 luggage; 91 gas)
Important is tire pressure, two times than regular (dont be frightened! use Goodrich T/A)
Last: You say dog to the V6. Does this mean the car`s values are unbelieveable? I am not familiar with this use.