Stant 45889 Engine Coolant Thermostat

Stant Superstat 45889 Thermostat Overview

The Stant Superstat 45889 is a 195-degree engine coolant thermostat for select GM compact cars, including Chevrolet Cavalier, Chevrolet Corsica, Pontiac Tempest, Buick Skyhawk, and Oldsmobile Firenza applications. Built for OE-temperature cooling control, it uses a high-venturi design and a larger piston to support stable coolant flow during higher-temperature, higher-load operation.

The Superstat thermostat line focuses on consistent temperature regulation and durable construction. For buyers searching for a 195 degree thermostat for 1987-1991 Chevrolet Cavalier or related GM platforms, Stant 45889 provides a direct-fit cooling system service part with a stainless steel flange and seal-specific fitment notes in the catalog data.

Key Features

• 195 Degrees Fahrenheit thermostat opening temperature
• High-venturi design for increased cooling capacity under load
• 25% larger piston diameter for stronger actuation than standard thermostats
• Stainless steel flange with burnished finish for added corrosion resistance
• Thicker flange construction for added stress relief
• Bypass plate diameter: 1.09 in.
• Flange diameter with seal: 1.9 in.; without seal: 1.725 in.
• Height from flange to bottom: 1.46 in.; height from flange to top of bridge: 0.87 in.

Detailed Description

Stant 45889 is an engine coolant thermostat engineered for OE-temperature service in compatible GM vehicles. The Superstat thermostat design uses a high venturi to improve coolant flow capacity when the engine is operating hot or under sustained load, while the larger piston helps deliver stronger opening force than a standard thermostat. That combination supports more consistent coolant regulation in everyday driving and demanding conditions.

This part number is commonly searched as Stant 45889 thermostat, 195 degree thermostat, and Superstat thermostat for Chevrolet Cavalier and Chevrolet Corsica cooling system repair. It also applies to Pontiac Tempest, Buick Skyhawk, and Oldsmobile Firenza models listed in the fitment data.

The Superstat product line is Stant’s premium thermostat family, built around precise temperature control and corrosion-resistant materials for cooling system maintenance.

Vehicle Fitment

• Fits 1987-1991 Chevrolet Cavalier, N/A. Notes: Temperature: 195 Degrees; Seal Included - Seal; Part Replacement Replaced by 13889; OE Temperature; Superstat Thermostat.
• Fits 1987-1991 Chevrolet Corsica, N/A. Notes: Temperature: 195 Degrees; Seal Included - Seal; Part Replacement Replaced by 13889; OE Temperature; Superstat Thermostat.
• Fits 1987-1991 Pontiac Tempest, N/A. Notes: Temperature: 195 Degrees; Seal Included - Seal; Part Replacement Replaced by 13889; OE Temperature; Superstat Thermostat.
• Fits 1987-1989 Buick Skyhawk, N/A. Notes: Temperature: 195 Degrees; Seal Included - Seal; Part Replacement Replaced by 13889; OE Temperature; Superstat Thermostat.
• Fits 1987-1988 Oldsmobile Firenza, N/A. Notes: Temperature: 195 Degrees; Seal Included - Seal; Part Replacement Replaced by 13889; OE Temperature; Superstat Thermostat.

This part cross-references 13889 for the same application.

Common Uses

• Replacing a thermostat that is stuck open and causing slow warm-up
• Replacing a thermostat that is stuck closed and contributing to overheating
• Restoring proper engine operating temperature on 1987-1991 Chevrolet Cavalier and Chevrolet Corsica models
• Addressing temperature control issues on Pontiac Tempest, Buick Skyhawk, and Oldsmobile Firenza cooling systems
• Service replacement for OE-temperature cooling system maintenance

Installation Notes

Verify the 195-degree specification and compare flange dimensions before installation. Clean the thermostat housing and sealing surfaces thoroughly, and inspect the coolant condition, gasket/seal surface, and housing for wear or corrosion before reassembly. Follow the vehicle service manual for coolant refill and bleed procedures to help prevent air pockets after installation.

Quality Assurance

Stant Superstat thermostats are built with a stainless steel flange and a thicker flange design to support corrosion resistance and stress relief in cooling system service. The catalog data identifies this part as a premium Superstat thermostat for OE-temperature applications.