{"id":433,"date":"2026-06-12T05:04:39","date_gmt":"2026-06-12T09:04:39","guid":{"rendered":"https:\/\/www.worldsbestdieseloil.com\/oil-guide\/1981-buick-lesabre-5-7l-8-cyl-diesel-maintenance-guide\/"},"modified":"2026-06-12T05:04:39","modified_gmt":"2026-06-12T09:04:39","slug":"1981-buick-lesabre-5-7l-8-cyl-diesel-maintenance-guide","status":"publish","type":"post","link":"https:\/\/www.worldsbestdieseloil.com\/oil-guide\/1981-buick-lesabre-5-7l-8-cyl-diesel-maintenance-guide\/","title":{"rendered":"1981 Buick LeSabre 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 LeSabre equipped with the 5.7L 8-cylinder Diesel engine (Engine Code N), the oil capacity is 7 quarts<\/strong> with a filter change. 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> and the AMSOIL Oil Filter (EAO64-EA)<\/a>.<\/p>\n

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

The 1981 Buick LeSabre 5.7L diesel requires an oil grade of CF. The specific viscosity depends on your operating environment: 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

Based on the vehicle specifications, AMSOIL provides several high-performance lubrication options to maintain this vintage diesel engine. Below are the recommended products for your maintenance needs.<\/p>\n

Engine Oil & Filter Kits<\/h3>\n
\n\n\n\n\n\n\n
Product Name<\/th>\nCode<\/th>\n<\/tr>\n
Signature Series 5W-30 Max-Duty Diesel Oil<\/td>\nDHDQT-EA<\/a><\/td>\n<\/tr>\n
Signature Series 10W-30 Max-Duty Diesel Oil<\/td>\nDTTQT-EA<\/a><\/td>\n<\/tr>\n
Heavy-Duty 10W-30 Synthetic Diesel Oil<\/td>\nADNQT-EA<\/a><\/td>\n<\/tr>\n
AMSOIL Oil Filter<\/td>\nEAO64-EA<\/a><\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Other Essential Fluids<\/h3>\n
\n\n\n\n\n\n\n
Component<\/th>\nAMSOIL Product & Code<\/th>\n<\/tr>\n
Antifreeze\/Coolant<\/td>\nPassenger Car & Light Truck Antifreeze<\/a> (ANTPC1G-EA<\/a>)<\/td>\n<\/tr>\n
Antifreeze (Concentrate)<\/td>\nPropylene Glycol Antifreeze<\/a> (ANT1G-EA<\/a>)<\/td>\n<\/tr>\n
Automatic Transmission Fluid<\/td>\nSignature Series ATF<\/a> (ATLPK-EA<\/a>)<\/td>\n<\/tr>\n
Automatic Transmission Fluid<\/td>\nOE Fuel-Efficient ATF<\/a> (OTLQT-EA<\/a>)<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Engine Oil Specifications<\/h3>\n
\n\n\n\n\n\n
Viscosity<\/th>\nCondition\/Note<\/th>\n<\/tr>\n
10W-30<\/td>\nBelow 16\u00b0C<\/td>\n<\/tr>\n
15W-40<\/td>\n-18 to 16\u00b0C<\/td>\n<\/tr>\n
30<\/td>\nAbove 0\u00b0C (Preferred for continuous driving)<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Oil Grade:<\/strong> CF<\/p>\n

Engine Oil Capacity & Torque<\/h3>\n
\n\n\n\n\n
Description<\/th>\nValue<\/th>\n<\/tr>\n
Capacity (with filter)<\/td>\n7 quarts<\/td>\n<\/tr>\n
Oil Drain Plug Torque<\/td>\n30 ft\/lbs<\/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

For a complete service including the replacement of the oil filter, this 5.7L diesel engine requires 7 quarts of oil. It is critical to verify the oil level using the dipstick after the refill to ensure accuracy.<\/p>\n

Automatic Transmission Fluid Specifications<\/h2>\n

The transmission requirements vary based on your specific model (THM350C, THM200-4R, THM200C, or THM250C). Note that manufacturer technical service bulletins have updated the specification from Dexron II or III to Dexron VI for these applications.<\/p>\n

Transmission Capacity Guide<\/h3>\n
\n\n\n\n\n\n\n
Transmission Type<\/th>\nTotal Fill<\/th>\nInitial Fill<\/th>\n<\/tr>\n
3-speed THM350C<\/td>\n10 quarts<\/td>\n3 quarts<\/td>\n<\/tr>\n
4-speed THM200-4R<\/td>\n11 quarts<\/td>\n5 quarts<\/td>\n<\/tr>\n
3-speed THM200C<\/td>\n9.4 quarts<\/td>\n3.5 quarts<\/td>\n<\/tr>\n
3-speed THM250C<\/td>\n10.8 quarts<\/td>\n4 quarts<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

Coolant Specifications & Capacity<\/h2>\n

Maintaining the cooling system is vital for diesel engine efficiency and longevity. The capacity depends on whether the vehicle is equipped with Air Conditioning (AC).<\/p>\n

\n\n\n\n\n
Configuration<\/th>\nCapacity<\/th>\n<\/tr>\n
With AC<\/td>\n18 quarts<\/td>\n<\/tr>\n
Without AC (O)<\/td>\n18.5 quarts<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

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

Owners of vintage diesel engines like the 5.7L Engine Code N should prioritize several key areas to ensure reliability:<\/p>\n