Spark Plug Gap Calculator | Auto Tools
Spark Plug Gap Calculator
Recommended Spark Plug Gap:
0.028 – 0.032 inches
How to Gap Spark Plugs Properly
- Use a spark plug gap tool (feeler gauge or wire-type).
- Check the manufacturer’s recommended gap.
- Gently adjust the ground electrode—don’t force it.
- Avoid damaging the center electrode or ceramic insulator.
Ensuring the correct spark plug gap is crucial for engine performance, fuel efficiency, and preventing misfires.
Our free Spark Plug Gap Calculator helps you find the recommended gap for your Ford, Toyota, Honda, Chevrolet, BMW, and other vehicles—plus a handy inch-to-mm converter and expert gapping tips.
Spark Plug Gap Chart (Common Vehicles)
Ford
| Model | Years | Engine | Standard Gap | Performance Gap |
|---|---|---|---|---|
| F-150 | 2015-2024 | 5.0L V8 | 0.028-0.031″ [0.71-0.79mm] | 0.026″ [0.66mm] |
| F-150 Raptor | 2017-2024 | 3.5L EcoBoost ⚡ | 0.028″ [0.71mm] | 0.025″ [0.64mm] |
| Mustang GT | 2018-2024 | 5.0L Coyote | 0.030-0.034″ [0.76-0.86mm] | 0.028″ [0.71mm] |
| Focus RS | 2016-2018 | 2.3L EcoBoost ⚡ | 0.026″ [0.66mm] | 0.024″ [0.61mm] |
| Powerstroke | 2020-2024 | 6.7L ⛽ | 0.030″ [0.76mm] | N/A |
Chevrolet/GMC
| Silverado 1500 | 2019-2024 | 6.2L V8 | 0.040″ [1.02mm] | 0.038″ [0.97mm] |
| Corvette C8 | 2020-2024 | 6.2L LT2 | 0.040″ [1.02mm] | 0.036″ [0.91mm] |
| Colorado Duramax | 2016-2024 | 2.8L ⛽ | 0.032″ [0.81mm] | N/A |
| Bolt EV | 2017-2024 | Electric 🔋 | N/A | N/A |
Toyota/Lexus
| Tundra | 2022-2024 | 3.5L TwinTurbo ⚡ | 0.031″ [0.79mm] | 0.029″ [0.74mm] |
| Prius Prime | 2016-2024 | 1.8L 🔋 | 0.043″ [1.09mm] | N/A |
| GR Supra | 2020-2024 | 3.0L B58 ⚡ | 0.022″ [0.56mm] | 0.020″ [0.51mm] |
| Land Cruiser | 2021-2024 | 3.4L TwinTurbo ⚡ | 0.028″ [0.71mm] | 0.026″ [0.66mm] |
Honda/Acura
| Civic Type R | 2017-2024 | 2.0L K20C ⚡ | 0.025″ [0.64mm] | 0.023″ [0.58mm] |
| Accord Hybrid | 2018-2024 | 2.0L 🔋 | 0.040″ [1.02mm] | N/A |
| NSX | 2017-2024 | 3.5L Hybrid 🔋 | 0.028″ [0.71mm] | 0.026″ [0.66mm] |
Dodge/Ram
| Challenger Hellcat | 2015-2024 | 6.2L Supercharged | 0.043″ [1.09mm] | 0.040″ [1.02mm] |
| Ram 1500 EcoDiesel | 2014-2024 | 3.0L ⛽ | 0.032″ [0.81mm] | N/A |
European Models
| BMW M3 | 2021-2024 | 3.0L S58 ⚡ | 0.022″ [0.56mm] | 0.020″ [0.51mm] |
| Audi RS5 | 2018-2024 | 2.9L TwinTurbo ⚡ | 0.024″ [0.61mm] | 0.022″ [0.56mm] |
| Porsche 911 Turbo | 2020-2024 | 3.7L TwinTurbo ⚡ | 0.024″ [0.61mm] | 0.022″ [0.56mm] |
Niche & Performance
| Tesla Model S Plaid | 2021-2024 | Electric 🔋 | N/A | N/A |
| Nissan GT-R | 2017-2024 | 3.8L TwinTurbo ⚡ | 0.031″ [0.79mm] | 0.028″ [0.71mm] |
| Jeep Wrangler 4xe | 2021-2024 | 2.0L PHEV 🔋 | 0.032″ [0.81mm] | N/A |
Spark Plug Gap Conversion (Inch to mm)
Use our built-in inch-to-mm converter or reference this chart
| Inches | Millimeters |
|---|---|
| 0.025″ | 0.64 mm |
| 0.028″ | 0.71 mm |
| 0.032″ | 0.81 mm |
| 0.040″ | 1.02 mm |
How to Measure & Adjust Spark Plug Gap
Tools You’ll Need:
- Feeler gauge or wire-type gap tool
- Spark plug gap adjuster (if correction is needed)
Step-by-Step Guide:
- Check the gap using a feeler gauge.
- Adjust carefully by bending the ground electrode—don’t touch the center electrode!
- Re-measure until perfect.
Warning: Forcing the gap can crack the insulator!
FAQs
1. What happens if my spark plug gap is too big?
A larger gap can cause weak sparks, misfires, and poor acceleration.
2. Can I use the same gap for all spark plugs?
No—gap sizes vary by engine (turbocharged engines often need smaller gaps).
3. Do iridium/platinum plugs need gapping?
Most come pre-gapped, but always verify (especially aftermarket plugs).
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