Spark Plug Charts - AutoChartGuide

Spark plug heat range chart infographic: NGK, DENSO, Champion and Bosch heat numbers on the same rows from DENSO's conversion table, hot to cold

Spark Plug Charts

Spark Plug Heat Range Chart 2026: Official Maker Scales

DENSO's published heat range conversion table for NGK, DENSO, Champion and Bosch, each maker's own scale, and what the makers say about going hotter or colder.

Spark plug cross reference chart infographic: NGK and DENSO equivalents for Champion RC12YC, RN9YC, Bosch FR7DC, FR8DC, Autolite 64 and 3924, and NGK BKR5E-11

Spark Plug Charts

Spark Plug Cross Reference Chart 2026: Official Maker Lists

NGK's and DENSO's own cross-references for common Champion, Autolite, Bosch and NGK plugs, and how often the two makers agree.

Briggs and Stratton Spark Plug Chart infographic: flathead 796112S/5095, OHV 491055S, gap .030 in, 15 ft-lb max

Spark Plug Charts

Briggs and Stratton Spark Plug Chart 2026: Official Gaps

Briggs & Stratton's official spark plug part numbers and gaps for flathead and OHV engines, plus the Quantum .020 in exception decoded.