Can i drive when the COOL indicator light is on?

[regulus]

Originally Posted by 07WYarisRS

Running an engine as you normally would when cold will shorten the life of the cylinders, pistons and rings. (three different metals all expand at different rates)
You can drive it cold but you must drive it easy
Most cars it 130-150 degress before the lights go out or guage starts to climb.
You don't need to wait for the light to go out but you do need to drive it very easy until it's warmed up to normal operating temps(5 minutes of driving)

Lately in the mornings it takes a couple minutes for the windshild to defrost and I have not noticed much of a difference in fuel mileage with the extra minute or two.

Remember Toyota is in the business of selling cars, not handing out tips that will let your car last 1,000,000km. Driving with out any warm up is a great because people don't like to wait and it does save a bit of fuel. But it will shorten the life of the engine.
Thats why it seems like engines now days don't seem to last like the engines from the 60's 70's and 80's. Back then the old carbed engines had to be warmed up before you could drive them with out stalling or hesitating badly. These engines lasted for ever even with garbage oils back then due to the long slow warm up.
Todays engines are FAR better in design and with proper care and warm up will last 2X as long. But EFI systems allow you to drive with a stone cold engine and that shortens the life of the engine. And that's why so many engines are dead before they ever hit 250,000km.

No, too much generalization and oversimplifying.