Automotive Calculators
MPG calculator, fuel cost for trips, tire size comparison, oil change interval, car payment, true cost.
📘 When to use these
Road trip planning, comparing fuel efficiency, shopping for tires, budgeting car payments, or understanding what your vehicle really costs. Essential math for every driver.
Quick examples:
Quick examples:
Tire 1
Tire 2
Tire 1 Diameter
24.97in
Tire 2 Diameter
25.4in
Size Difference
0.43in
Speedo Error
1.7%
📐 Step-by-step breakdown:
Tire 1: 225/45R17
Sidewall = 225mm × 45% = 101.25mm
Diameter = (101.25 × 2) / 25.4 + 17" = 24.97"
Tire 2: 235/40R18
Diameter = 25.4"
Difference: 0.43" (1.7% speedo error)
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%/yr
months
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