Vehicle Diagnostic Tools
Use these tools alongside the guides to confirm trouble codes, analyze charging and vacuum patterns, compare tire sizes, and choose the right battery fitment.
What Battery Group Size Fits My Car?
Match group size, terminal layout, and CCA for the right replacement.
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How Many Cold Cranking Amps Do I Need?
Estimate the cold cranking amps needed for your engine and climate.
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Alternator Voltage Readings: What's Normal?
Interpret charging voltage, ripple, and cable drop readings in one pass.
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Compression Test Results: Are Your Numbers Good?
Analyze cylinder balance and compression spread in seconds.
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50/50 Coolant Mix Calculator
Calculate concentrate and water amounts for the right mix.
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Vacuum Gauge Readings: What's Normal at Idle?
Translate idle vacuum and needle behavior into targeted next checks.
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Fuel Cost & MPG Calculator
Convert MPG and L/100km, estimate costs, and track fuel economy changes.
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Fuel Trim Readings: STFT & LTFT Interpreter
Understand STFT and LTFT readings to spot lean or rich conditions.
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Which Cylinder Is Misfiring? P0301-P0312 Code Helper
Map P0301-P0312 codes to cylinders using common layouts.
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Is Your Parasitic Draw Normal? Battery Drain Calculator
Estimate how long a key-off draw will drain your battery.
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What RPM Should My Car Be at Highway Speed?
Estimate road speed from RPM, gearing, and tire diameter.
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Tire Size & Diameter Calculator
Compare tire sizes to keep speedometer, clearance, and gearing in line.
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