Thread: Gearing and tire size View Single Post
 03-24-2019, 10:34 AM #2 (permalink) California98Civic Cyborg ECU     Join Date: Mar 2011 Location: Coastal Southern California Posts: 5,967 Black and Green - '98 Honda Civic DX Coupe Team Honda 90 day: 66.42 mpg (US) Black and Red - '00 Nashbar Custom built eBike 90 day: 3671.43 mpg (US) Thanks: 2,239 Thanked 1,955 Times in 1,331 Posts This site offers the formula for how to use tire size to calculate tire diameter: https://auto.howstuffworks.com/auto-...size-chart.htm tire diameter: (CROSS SECTION WIDTH x 0.ASPECT RATIO x 2 ÷ 25.4) + WHEEL DIAMETER = OVERALL TIRE DIAMETER For Example: 235/45ZR-17 (235 x 0.45 x 2 ÷ 25.4) + 17 = 25.327" And here's a calculator for the rest of your query: https://tiresize.com/gear-ratio-calculator/ __________________ See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
 The Following 2 Users Say Thank You to California98Civic For This Useful Post: Fat Charlie (03-24-2019), Taylor95 (03-24-2019)