Is the Yaris mostly for Urban Transportation?

[Dorkinheimer]

Yes, changing the diameter of the wheel will affect the rpm at a given speed. Everyone knows that. The rpm will still be 2800 at 100 kmh, no change on the dials, but the car will be going 102 instead of 100for example, all depending on the size of the wheel you change it forl

Go here http://www.miata.net/garage/tirecalc.html

Enter 1756514, and then 1856015 and you'll see a 3.4% change SO, the car will be going at 103.4 and the speedometer will mark 100 kmh. The car will be going at 103.4, the speedometer marks 100, the rpm marks 2800

So, you go 3.4% faster for the same RPM

Since your car goes up 100 rpm for every 4 kmh in 5th gear, with the manual transmission, you lose about 100 rpm with the 15 inch tires compared to the 14 inch tires.

[jambo101]

Originally Posted by Dorkinheimer

Yes, changing the diameter of the wheel will affect the rpm at a given speed. Everyone knows that. The rpm will still be 2800 at 100 kmh, no change on the dials, but the car will be going 102 instead of 100for example, all depending on the size of the wheel you change it forl

Go here http://www.miata.net/garage/tirecalc.html

Enter 1756514, and then 1856015 and you'll see a 3.4% change SO, the car will be going at 103.4 and the speedometer will mark 100 kmh. The car will be going at 103.4, the speedometer marks 100, the rpm marks 2800

So, you go 3.4% faster for the same RPM

Since your car goes up 100 rpm for every 4 kmh in 5th gear, with the manual transmission, you lose about 100 rpm with the 15 inch tires compared to the 14 inch tires.

And to get this marginal gain in mph-vs-engine :rpm you are going to change all your rims and tires?Certainly doesnt make any financial sense.I just put 200k on a Miata over the last 6yrs and at 80mph it was revving 4500rpm:my moms older Firebird with overdrive will do the same 80mph at 1600rpm.