this car is a 92 galant import,so has the wrong gearbox for the eu.at 3000rpm its doing 56mph! so if i fit larger tyres the revs should drop. the question is how big can i fit and how much will it reduce the revs?

I understand that hoses are reinforced but are tyres only inflated to about 5lbs psi to take expansion into consideration. As a P.S. to another question congrats to the HX558 team on completion to get this aircraft flying again.

If I have two Toyota Land Cruisers, one has the original tyres, and the other have larger scale circumference tyres, would the two cars be moving in paralel at the same speedometer reading?