Originally Posted by Rockyherald
Originally Posted by suss6052
Why is that? If you never used the ice scraper you wouldn't be able to go anywhere for at least an additional 5-15 minutes while you burn gas idling in order to defrost the windows and who has that kind of time in the morning before work, let alone wants to burn the additional fuel rather than what is necessary for the defrost + scraping the window?
Scraping the windows on the older car never did any specific damage afaik, as plastic is softer than glass.
Glass will scratch. There is dirt on the windshield and when you use a scraper that will grind in the dirt. Plastic WILL scratch glass. My Plastic Vacuum cleaner tipped over once and rubbed a windshield I had in the glass rack in the back of my truck. I had to buff out the plastic on glass scratches before I could install the glass. I've done it and i've seen plenty of other cars scratched with plastic scrapers. Even a pine needle caught under the wiper blade will scratch. Done that too. Not deep type scratches but rubs which are scratches nonetheless. I take the time to warm up my vehicles, as a few minutes of gas is cheaper than replacing damaged glass. warm water helps speed up the process also.(might freeze back up immediately though if you live in Minnesota)
If you want to use an ice scraper go ahead.
Warm water increases the risk of thermal shocking and cracking the glass that way. That doesn't seem like a good solution at all as that is more likely to stress crack frozen glass.
Since we don't have the option of the quick clear/ instaclear windshield that they get in Europe it takes a whole lot longer and is a whole lot more inefficient as one must wait for the coolant to get warm enough to defrost the windows. Although the instaclear windshield is a lot more expensive because of the fine metal mesh that is embedded in the glass in order to electrically heat the front windscreen to instantly clear the window (i.e. much quicker than using the coolant and clearing it from the bottom up.)
I didn't say I like having to scrape windshields, but over the lifetime of the vehicle you'd waste a lot more gas idling for extended periods and cause more damage to the engine over time than you'd theoretically save by not scraping the glass.
Cold engines are less efficient and they warm up best by being driven, and although the focus can have the active grille shutters to aid warm up in cold weather its still going to take time to heat up the block and the coolant before it could actually start to defrost the glass.
I've been idling the car of late with the defroster on and the mileage has taken a nose dive even with just 5-10 minutes of idling in the morning while clearing the windows sufficiently to see safely.