210 is fine. 150 is very bad and will lead to excessive engine wear, assuming it's correct. Feel the upper radiator hose after driving on the highway. It should be too hot to hold onto for very long. If it is, your gauge is not reading correctly. If the hose is cool the thermostat is sticking open.
Engine parts, pistons in particular, are machined to fit perfectly when they expand from normal engine temperatures. That's why 99 percent of engine wear takes place while the engine is warming up, and very little wear takes place on long highway-speed drives.
We like to get Dex-Cool out whenever possible. GM advertised it as "lifetime" coolant to trick people. It made their cost of maintenance look lower than for their competitors and they advertised that. Then, once you bought the vehicle, it says right on the coolant reservoir to replace the coolant every three years. That's because the additives wear out. Those are water pump lubricant and corrosion inhibitors. Even the Dex-Cool manufacturer recommends replacing it every two years, not every three. GM already has a lot of trouble with corroded heater cores and radiators so you don't want to do anything to provoke that. Use a regular name brand antifreeze but be sure to flush all the old stuff out first. The two are not compatible and should not be mixed.
Tuesday, June 18th, 2013 AT 11:01 AM