calculating mpg with 195/60R15 tires

[brg88tx]

i just bought a used yaris and the previous owner put 195/60R15 tires on instead of the stock 185/60R15. i found a tire size calculator that said my tires were slightly bigger and my speedometer would read 1.98% too slow.

so, in order to accurately calculate my mpg i would take the mpg figure i come up with and multiply it by 1.0198, right?

[Yaris Hilton]

Yeah, maybe, but that's nitpickier than I'm willing to be.

[STC]

So, according to this calculator your speed is 1.98% too slow on your speedometer? I would imagine this would be a fair assessment.

Say you rounded up to 2.00%. Then traveling @ 60mph according to your speedometer... you are actually traveling 1.200mph faster - 61.2mph.

Yes this is right... you would need to multiply by 0.0198 (or 0.0200) and add to the mpg figure if you want to be accurate.

Cheers!

[RETRO]

Best to use a GPS and compare the trip on the car and on the gps.