GX550 Real World MPG

[Bluegill]

I’m curious for those who have bigger tire diameters than stock how do you monitor your speed? I have been using Waze/iPhone speedometer app but I’m not sure how accurate those are.

I have a mph app that I occasionally turn on and let it display speed while I'm driving on the highway. 70 on the dash display is really 75, 80 is about 86. I have to set my cruise around 75 to mostly keep up with traffic, which is really 80/81 mph.

 

[YellowLab]

They measured it going downhill with 100 psi in the tires, a 50 mph tailwind, in a vacuum, with self-contained-breathing-apparatus-equipped elves pushing the vehicle while it was in neutral.

Do you know how many angels were dancing on the head of a pin when that was happening?