Deliver quick starts and the power your engine needs with the Autolite Copper Spark Plug 847. It's a direct-fit replacement for a broad list of 1970s–80s GM applications, including the 1975 Buick Apollo (V8-4.3L), 1975-1976 Buick Century (V6-3.8L), 1976-1980 Buick Electra (V8-5.7L), 1976-1980 Cadillac Seville (V8-5.7L), 1975-1981 Oldsmobile Cutlass (V8-4.3L), and 1973-1976 Oldsmobile 98 (V8-7.5L) — see the Buyer's Guide tab for the full list of 98 applications.
- Copper core center electrode: aids thermal control and improves resistance to fouling.
- High nickel alloy center and ground electrode: engineered to provide extended life.
- High alumina multi-rib ceramic insulator: provides thermal conductivity and superior insulation for increased strength.
- Nickel-plated shell: corrosion resistant for increased durability.
Key specs: Manufacturer Heat Range 5, M14 - 1.25 metric thread with a 14 mm thread diameter, 0.374 in (9 mm) reach, 13/16 in hex, flat seat with a washer included, and a resistor type rated at 5000 ohm. Factory pre-gap is 0.07 in (1.8 mm). Sold individually; quantity varies by engine (many listed applications use 8, while the V6-3.8L applications use 6). Backed by a 2-year limited warranty. Country of origin: China. Manufacturer part number 847.
This part cross-references / interchanges with the following part numbers:
Frequently Asked Questions
What is the Autolite 847?
It's a copper spark plug with a copper core center electrode, high nickel alloy center and ground electrodes, a high alumina multi-rib ceramic insulator, and a corrosion-resistant nickel-plated shell.
How many spark plugs do I need?
They're sold individually and quantity varies by engine — many listed applications use 8, while the V6-3.8L applications use 6. Confirm your engine's plug count.
What are the key specifications?
Heat Range 5, M14 - 1.25 metric thread (14 mm diameter), 0.374 in (9 mm) reach, 13/16 in hex, flat seat with washer included, and resistor type rated at 5000 ohm.
Is the 847 pre-gapped?
It ships with a factory pre-gap of 0.07 in (1.8 mm). Check the gap against your vehicle's specification and adjust if the service information calls for a different setting.
What vehicles does the 847 fit?
It fits many 1970s–80s GM models, including Buick Apollo, Century, Electra, Cadillac Seville, and Oldsmobile Cutlass and 98. See the Buyer's Guide tab for the full list.
Write a Review