Stant 45899 Engine Coolant Thermostat

Stant Superstat 45899 Thermostat Overview

The Stant Superstat 45899 engine coolant thermostat is a 195-degree OE-temperature replacement built for consistent coolant control in a wide range of GM vehicles. It is a fitment-based choice for drivers servicing applications such as the Chevrolet Malibu, Pontiac Grand Prix, and Buick Regal.

Key Features

• 195-degree thermostat temperature rating for OE-style engine warm-up and cooling control
• High-venturi design for improved coolant flow during high-temperature, high-load operation
• 25% larger piston diameter for increased opening force versus standard thermostats
• Stainless steel flange with a burnished finish for added corrosion resistance and stress relief
• Thicker flange construction for added durability
• Seal included per listed fitment notes

Product Details

Built under the Stant Superstat thermostat line, part number 45899 is engineered for applications that need stable operating temperature control without deviating from OE temperature targets. The 195 Degrees specification matches the listed factory-style applications, while the larger piston and high-venturi design help maintain coolant movement when the engine is under load. This makes the Stant 45899 a practical replacement for vehicles that rely on precise thermostat response for everyday driving and demanding conditions.

Compatible With select 1987-2009 Chevrolet, Buick, Pontiac, GMC, Saturn, Oldsmobile, Cadillac, and related GM platforms, including Chevrolet Equinox, Pontiac Torrent, Buick Rendezvous, and Chevrolet Silverado 2500 HD Classic applications listed in the fitment data. Part number 45899 is also referenced in searches for Stant 45899 thermostat and Superstat 45899 coolant thermostat.

Common Problems This Part Can Address

• Engine running cooler or hotter than the intended OE temperature range
• Delayed warm-up after cold starts
• Unstable coolant temperature during towing, hauling, or stop-and-go driving
• Thermostat sticking open or closed
• Corrosion-related wear at the thermostat flange area

Installation Notes and Tips

Verify the 195-degree temperature rating and match the vehicle application before installation. Confirm the flange dimensions, bypass plate diameter, and housing fitment against the original thermostat. Clean the sealing surfaces thoroughly and inspect the cooling system for contamination, leaks, or worn hoses before reassembly. For body fitment, examples include Fits 2005-2007 Chevrolet Equinox, N/A; Fits 2006-2009 Pontiac Torrent, N/A; and Fits 2002-2007 Buick Rendezvous, N/A.

Quality Assurance

Stant Superstat thermostats are built to OE-style specifications with materials selected for durability and corrosion resistance. The stainless steel flange and thicker flange design support long-term service in cooling system applications. This part cross-references no listed interchange numbers for the same application.