AE86 DENSO Spark Plug Set | 4A-GE (1983-87 Corolla)

DENSO Double Platinum / Iridium TT Spark Plug Set

For 1983–1987 Toyota Corolla AE86 Trueno / Levin and 1985–1987 U.S.-Market Corolla Sport AE86 (GT-S)

Overview

Restore dependable ignition performance on the 1983–1987 Toyota Corolla AE86 Trueno / Levin and 1985–1987 U.S.-market Corolla Sport GT-S with a four-plug DENSO spark plug set designed for the factory naturally aspirated 4A-GE engine. Choose the Double Platinum factory-specification replacement or the modern Iridium TT alternative.

Factory Pre-Gapped & Direct-Fit — Both Options. DENSO Double Platinum and Iridium TT are both plug-and-play replacements for the factory naturally aspirated 4A-GE, each supplied at its specified factory-set gap. Double Platinum has a 1.1 mm (0.044 in.) gap matching the original plug specification, while Iridium TT has a 1.0 mm (0.040 in.) gap designed for its modern fine-wire iridium center and platinum twin-tip ground electrodes. The Iridium TT's slightly smaller preset is intentional—not a fitment difference or a reason to change its gap to 1.1 mm. Both share DENSO heat range 16 and the correct thread, reach, and gasket-seat design for the stock 4A-GE.

Key Features

• Four matching spark plugs in every set for the 4-cylinder 4A-GE.
• Double Platinum: original-style platinum electrode design for a factory-specification replacement.
• Iridium TT: fine iridium center and platinum needle-style ground electrode for a modern twin-tip design.
• Factory Pre-Gapped & Direct-Fit: Both are plug-and-play stock 4A-GE replacements at their own factory settings: 1.1 mm Double Platinum or 1.0 mm Iridium TT.
• Resistor-type construction and DENSO heat range 16 for the specified 4A-GE application.
• Direct-fit dimensions: M14 × 1.25 thread, 19 mm reach, 16 mm hex and gasket seat.

Vehicle Fitment

Toyota Corolla AE86

• 1983–1987 Trueno (JDM) — factory 4A-GE
• 1983–1987 Levin (JDM) — factory 4A-GE
• 1985–1987 GT-S (U.S.-Market) — factory 4A-GE, manual transmission

Fitment Notes

• 4A-GE naturally aspirated engines only. Does not fit the factory 4A-C engine in the Corolla Sport SR5.
• Japanese-market 4A-GE manual models and factory automatic models from 1985 are covered. U.S.-market GT-S models were manual only.
• Engine swaps, turbocharged or supercharged conversions, and ignition systems with modified heat-range requirements are outside this factory-engine fitment.
• Both electrode designs are direct-fit choices for the original 4A-GE ignition system; the Iridium TT's 1.0 mm preset is normal for its twin-tip design.

Product Specifications

Brand: DENSO
Product Type: Resistor spark plug set
Engine: Naturally aspirated 4A-GE
Quantity: 4 matching spark plugs per set
Heat Range: DENSO 16
Thread Size: M14 × 1.25
Thread Reach: 19 mm
Hex Size: 16 mm
Seat Type: Gasket (flat seat)
Double Platinum Factory Pre-Gap: 1.1 mm (0.044 in., nominal)
Iridium TT Factory Pre-Gap: 1.0 mm (0.040 in., nominal)

Which Spark Plug Is Right for You?

Double Platinum — Best for Factory-Style Restorations & Everyday Value

Choose Double Platinum if you're restoring your AE86 to factory specifications or want dependable spark plugs for daily driving at a lower price. It's an excellent choice for stock 4A-GE engines when long-term reliability and value matter most.

Iridium TT — Best for Spirited Driving & Long Service Life

Choose Iridium TT if you regularly drive your AE86, enjoy spirited driving, and want DENSO's premium, long-life spark plugs. They're designed to support consistent ignition and responsive acceleration, although a noticeable performance improvement over properly functioning Double Platinum plugs isn't guaranteed.

Prefer NGK? The AE86 NGK Spark Plug Set offers Laser Platinum and Iridium IX alternatives for the same factory 4A-GE applications.

Our Recommendation: For most stock, restored, or casually driven AE86s, choose Double Platinum for factory-style reliability and value. Choose Iridium TT if you want a premium long-life option designed with responsive driving in mind. Both are factory pre-gapped, direct-fit replacements.

Supporting Ignition Wires

Worn plug wires can still cause ignition misfires after replacing the plugs. For a broader 4A-GE ignition refresh, the AE86 NGK Blue Silicone Spark Plug Wire Set is a separately sold matching wire option.

Available Configurations

Choose one spark plug type. Each option is sold as a complete four-plug set.

Double Platinum

• Includes: (4) matching DENSO Double Platinum spark plugs
• Factory-style platinum design with a 1.1 mm nominal preset gap

Iridium TT

• Includes: (4) matching DENSO Iridium TT spark plugs
• Fine-wire iridium / platinum twin-tip design with a 1.0 mm nominal preset gap