Denso 5027 Spark Plug

Denso 5027 U-Groove Spark Plug Overview

Denso 5027 is a conventional spark plug built for older ignition systems that need reliable secondary ignition performance. Its U-Groove ground electrode design helps improve ignitability for smoother combustion and better engine efficiency in the vehicles listed below.

Compatible With classic Buick, Chevrolet, Ford, Lincoln, Mercury, Oldsmobile, Pontiac, Cadillac, Jeep, and select GM applications, this Denso U-Groove Conventional spark plug is a direct-fit service part for a wide range of 1975-1987 vehicles. The Denso 5027 is also cross-referenced to Denso Auto Parts T16PR-U15 for the same application.

Key Features

• U-Groove ground electrode tip design for improved ignitability
• Conventional spark plug construction for secondary ignition service
• 5000 ohm resistance for stable ignition performance
• Copper center electrode core material for dependable heat transfer
• Nickel center and ground electrode tip materials
• Tapered seat design with 14.00 mm thread diameter
• 16.0 mm hex size and 11.60 mm reach
• Manufacturer heat range 16
• Pre-gapped at 1.5

Product Details

The Denso U-Groove Conventional line focuses on practical ignition performance for older engines that benefit from a traditional spark plug design. On the Denso 5027, the U-shaped ground electrode helps expose the spark kernel more effectively, which supports cleaner combustion in applications such as Buick Regal, Chevrolet Monte Carlo, Pontiac Grand Prix, Ford Mustang, and Oldsmobile Cutlass models. This part number is also listed under GM interchange references including 5613302, 5613794, 5613877, 5613935, 19300873, 19310656, and 88901022.

What This Spark Plug Helps Address

• Hard starting caused by worn or inefficient spark plugs
• Rough idle from inconsistent ignition firing
• Misfire conditions related to weak spark delivery
• Reduced combustion efficiency in aging ignition systems
• Service replacement needs for original-equipment-style applications

Installation Notes and Fitment

Verify thread diameter, reach, seat type, and heat range before installation. The Denso 5027 uses a tapered seat, 14.00 mm thread diameter, 11.60 mm reach, and 16 mm hex size, so matching the engine specification is important for proper sealing and combustion chamber fit. Confirm the vehicle application against the listed fitment before service.

• Fits 1979-1987 Buick Regal, N/A
• Fits 1977-1985 Buick Century, N/A
• Fits 1978-1985 Buick LeSabre, N/A
• Fits 1975-1976 Buick LeSabre, N/A
• Fits 1981-1985 Buick Riviera, N/A
• Fits 1978 Buick Riviera, N/A
• Fits 1976 Buick Riviera, N/A
• Fits 1978-1980 Buick Skyhawk, N/A
• Fits 1979 Buick Skylark, N/A
• Fits 1978-1987 Chevrolet Monte Carlo, N/A
• Fits 1980-1985 Chevrolet Caprice, N/A
• Fits 1980-1985 Chevrolet Impala, N/A
• Fits 1978-1984 Chevrolet El Camino, N/A
• Fits 1978-1983 Chevrolet Malibu, N/A
• Fits 1980-1981 Chevrolet Camaro, N/A
• Fits 1978-1980 Chevrolet Monza, N/A
• Fits 1976-1985 Mercury Grand Marquis, N/A
• Fits 1977-1984 Mercury Cougar, N/A
• Fits 1979-1983 Mercury Capri, N/A
• Fits 1977-1982 Mercury Marquis, N/A
• Fits 1978-1982 Mercury Zephyr, N/A
• Fits 1975-1987 Pontiac Grand Prix, N/A
• Fits 1975-1986 Pontiac Bonneville, N/A
• Fits 1975-1981 Pontiac Catalina, N/A
• Fits 1975-1981 Pontiac Firebird, N/A
• Fits 1979-1981 Pontiac Grand LeMans, N/A
• Fits 1975-1977 Pontiac Grand LeMans, N/A
• Fits 1979-1981 Pontiac LeMans, N/A
• Fits 1975-1977 Pontiac LeMans, N/A
• Fits 1978-1980 Pontiac Grand Am, N/A
• Fits 1975 Pontiac Grand Am, N/A
• Fits 1979-1980 Pontiac Sunbird, N/A
• Fits 1983-1984 Pontiac Parisienne, N/A
• Fits 1981 Pontiac Parisienne, N/A
• Fits 1980-1985 Oldsmobile Cutlass Ciera, N/A
• Fits 1978-1987 Oldsmobile Cutlass Supreme, N/A
• Fits 1985-1987 Oldsmobile Cutlass Salon, N/A
• Fits 1978-1980 Oldsmobile Cutlass Salon, N/A
• Fits 1978-1981 Oldsmobile Cutlass, N/A
• Fits 1980-1983 Oldsmobile Cutlass Cruiser, N/A
• Fits 1977-1985 Oldsmobile Delta 88, N/A
• Fits 1985 Oldsmobile 98, N/A
• Fits 1981-1983 Oldsmobile 98, N/A
• Fits 1975 Oldsmobile 98, N/A
• Fits 1981-1984 Oldsmobile Toronado, N/A
• Fits 1977-1980 Oldsmobile Starfire, N/A
• Fits 1978-1982 Oldsmobile Omega, N/A
• Fits 1975 Oldsmobile Custom Cruiser, N/A
• Fits 1982-1985 Cadillac DeVille, N/A
• Fits 1981-1982 Cadillac Eldorado, N/A
• Fits 1980-1982 Cadillac Fleetwood, N/A
• Fits 1981-1982 Cadillac Seville, N/A
• Fits 1982-1984 Lincoln Continental, N/A
• Fits 1977-1980 Lincoln Continental, N/A
• Fits 1984 Lincoln Mark VII, N/A
• Fits 1980-1983 Lincoln Mark VI, N/A
• Fits 1981-1984 Lincoln Town Car, N/A
• Fits 1977-1980 Lincoln Versailles, N/A
• Fits 1981-1983 Ford LTD, N/A
• Fits 1977-1979 Ford LTD, N/A
• Fits 1979-1983 Ford Mustang, N/A
• Fits 1977-1983 Ford Thunderbird, N/A
• Fits 1978-1982 Ford Fairmont, N/A
• Fits 1980-1983 Jeep CJ5, N/A
• Fits 1980-1983 Jeep CJ7, N/A
• Fits 1981-1983 Jeep Scrambler, N/A

Quality Assurance

Denso manufactures this spark plug as part of its U-Groove Conventional line, using nickel and copper electrode materials with a pre-set gap specification for consistent service replacement. The part number 5027 is built to match the listed OE-style applications and interchange references.