{"id":765,"date":"2026-07-05T01:37:27","date_gmt":"2026-07-05T05:37:27","guid":{"rendered":"https:\/\/www.worldsbestdieseloil.com\/oil-guide\/1981-buick-riviera-5-7l-8-cyl-diesel-maintenance-guide\/"},"modified":"2026-07-05T01:37:27","modified_gmt":"2026-07-05T05:37:27","slug":"1981-buick-riviera-5-7l-8-cyl-diesel-maintenance-guide","status":"publish","type":"post","link":"https:\/\/www.worldsbestdieseloil.com\/oil-guide\/1981-buick-riviera-5-7l-8-cyl-diesel-maintenance-guide\/","title":{"rendered":"1981 Buick Riviera 5.7L Diesel Maintenance Guide: Oil & Fluid Specs"},"content":{"rendered":"
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\"AMSOIL
AMSOIL diesel oil guide for trucks, vans, SUVs and diesel engines<\/figcaption><\/figure>\n

For the 1981 Buick Riviera with the 5.7L 8-cylinder Diesel engine (Engine Code N), the oil capacity is 7 quarts<\/strong> (including filter replacement). Recommended viscosities include 10W-30<\/strong> for temperatures below 16\u00b0C, 15W-40<\/strong> for -18 to 16\u00b0C, and 30 weight<\/strong> for continuous driving above 0\u00b0C. AMSOIL recommends using Signature Series 10W-30 Max-Duty Diesel Oil<\/a> (DTTQT-EA<\/a>) paired with an AMSOIL Oil Filter<\/a> (EAO64-EA<\/a>).<\/p>\n

What oil does a 1981 Buick Riviera 5.7L Diesel take?<\/h2>\n

The 1981 Buick Riviera with the 5.7L 8-cylinder diesel engine requires an oil grade of CF. Viscosity selection should be based on ambient operating temperatures: use 10W-30 for temperatures below 16\u00b0C, 15W-40 for temperatures between -18 to 16\u00b0C, and a 30 weight oil is preferred for continuous driving when temperatures are above 0\u00b0C.<\/p>\n

AMSOIL product recommendations<\/h2>\n

The following AMSOIL products are recommended for the 1981 Buick Riviera 5.7L Diesel to ensure optimal protection and performance.<\/p>\n

Engine Oil Options<\/h3>\n
\n\n\n\n\n\n
Product Name<\/th>\nViscosity<\/th>\nCode<\/th>\n<\/tr>\n
AMSOIL Signature Series Max-Duty Diesel Oil<\/td>\n10W-30<\/a><\/td>\nDTTQT-EA<\/a><\/td>\n<\/tr>\n
AMSOIL 10W-30 Heavy-Duty Synthetic Diesel Oil<\/td>\n10W-30<\/a><\/td>\nADNQT-EA<\/a><\/td>\n<\/tr>\n
AMSOIL Signature Series Max-Duty Diesel Oil<\/td>\n5W-30<\/a><\/td>\nDHDQT-EA<\/a><\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Note: Oil Grade is CF.<\/em><\/p>\n

Filtration & Coolant<\/h3>\n
\n\n\n\n\n\n
Component<\/th>\nProduct Name<\/th>\nCode<\/th>\n<\/tr>\n
Oil Filter<\/td>\nAMSOIL Oil Filter<\/td>\nEAO64-EA<\/a><\/td>\n<\/tr>\n
Antifreeze<\/td>\nAMSOIL Passenger Car & Light Truck<\/td>\nANTPC1G-EA<\/a><\/td>\n<\/tr>\n
Antifreeze<\/td>\nAMSOIL Propylene Glycol<\/td>\nANT1G-EA<\/a><\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Transmission & Gear Lubricants<\/h3>\n
\n\n\n\n\n\n\n
Component<\/th>\nProduct Name<\/th>\nCode<\/th>\n<\/tr>\n
Automatic Trans Fluid<\/td>\nAMSOIL Signature Series Fuel-Efficient<\/td>\nATLPK-EA<\/a><\/td>\n<\/tr>\n
Automatic Trans Fluid<\/td>\nAMSOIL OE Fuel-Efficient<\/td>\nOTLQT-EA<\/a><\/td>\n<\/tr>\n
Front Differential<\/td>\nAMSOIL SEVERE GEAR 80W-90<\/a><\/td>\nAGLPK-EA<\/a><\/td>\n<\/tr>\n
Front Differential<\/td>\nAMSOIL SEVERE GEAR 75W-90<\/a><\/td>\nSVGPK-EA<\/a><\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Engine Oil Specifications<\/h3>\n
\n\n\n\n\n
Specification<\/th>\nDetails<\/th>\n<\/tr>\n
Oil Grade<\/td>\nCF<\/td>\n<\/tr>\n
Drain Plug Torque<\/td>\n30 ft\/lbs<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Oil Capacity Details<\/h3>\n
\n\n\n\n
Description<\/th>\nCapacity<\/th>\n<\/tr>\n
Total Capacity (with filter)<\/td>\n7 quarts<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Note: Always check the oil level after refilling.<\/em><\/p>\n

How much oil does it take with a filter change?<\/h2>\n

A complete oil and filter service for this vehicle requires 7 quarts of oil. It is critical to verify the oil level manually after the refill process to ensure accuracy.<\/p>\n

Automatic Transmission Fluid Specifications<\/h2>\n

For the automatic transmission (THM325), the AMSOIL lookup notes that the specification has been updated from Dexron II or III to Dexron VI per a manufacturer Technical Service Bulletin. The total fill capacity for the 3-speed THM325 is 12 quarts, while the initial fill capacity is 5 quarts (this does not include the differential).<\/p>\n

Differential and Cooling System Data<\/h2>\n

Front Differential<\/h3>\n

The front differential requires GL-5 All TEMPS 80W-90 lubricant. The confirmed capacity for the front differential is 3.2 pints.<\/p>\n

Cooling System<\/h3>\n

The cooling system has a total capacity of 18 quarts. AMSOIL offers both a 50\/50 pre-mix ethylene glycol formulation and a concentrated propylene glycol option that requires mixing with distilled or high-quality water.<\/p>\n

Common diesel oil-related concerns and how AMSOIL products may help<\/h2>\n
\n\n\n\n\n\n
Concern<\/th>\nWhy it matters<\/th>\nAMSOIL product from this lookup<\/th>\nHow it may help<\/th>\nImportant limitation<\/th>\n<\/tr>\n
Engine Wear<\/td>\nDiesel engines face high pressure and friction.<\/td>\nDTTQT-EA<\/a><\/td>\nDelivers up to 6X more wear protection.<\/td>\nRequires proper service intervals.<\/td>\n<\/tr>\n
Contaminants<\/td>\nSmall particles can cause internal damage.<\/td>\nEAO64-EA<\/a><\/td>\n99% efficiency at 20 microns.<\/td>\nFilter must be replaced regularly.<\/td>\n<\/tr>\n
Thermal Stress<\/td>\nHigh temperatures can degrade oil.<\/td>\nDTTQT-EA<\/a><\/td>\nExcels in extreme temperatures.<\/td>\nNot a substitute for cooling system repair.<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Diesel maintenance notes for this vehicle<\/h2>\n