Don't pour water on frigid windshield

Q: Is it safe to use warm water to remove ice from my windshield in winter?

Q: Is it safe to use warm water to remove ice from my windshield in winter?

A: No. Applying hot, warm or even cold water to an ice-covered windshield, rather than using an ice scraper alone, could cause the glass to crack due to the sudden temperature change.

A much safer alternative is to use an alcohol-based solution made for this purpose, such as Frost Buster or Prestone Heat. In a pinch, rubbing alcohol from your medicine cabinet will also do the trick.

These products are flammable, so don’t smoke when applying. They’re also poisonous if swallowed, so store them safely away from children.

Q: Will running too many electrical accessories (DVD player, heat/massage seat, etc.) at once overload my minivan’s electrical system?

A: Electrical engineer Eli Melnick of Start Auto Electric in Toronto ( replies:

Simultaneously running multiple electrical accessories increases the load on the alternator.

However, most modern vehicles have alternators that are designed to carry this load. DVD players actually draw relatively little power in comparison to the “biggies” such as rear-window defoggers, or seat and steering-wheel heaters.

When stuck in stop-and-go traffic, it’s advisable to shut off as many heavy-load electrical accessories as possible.

This is due to the fact that at idle speed, the alternator is turning too slowly to produce the power required to support the combined loads that are turned on.

The shortfall is made up by the battery, which has a limited reserve capacity, so ultimately you could find yourself stuck with a dead battery.

Q: What is the current letter rating for gasoline engine oil?

A: Mike Cassaday, the fuel quality and environmental planning manager for Suncor Energy Products, replies:

At present, gasoline engine oil carries an “SM” rating from the American Petroleum Institute (API) and a “GF-4” specification from the International Lubricant Standardization and Approval Committee (ILSAC).

Both organizations state that SM-rated oils are fully backward-compatible for use in older gasoline engines.

For modified engines, check with the original equipment manufacturer and your mechanic for specific lubricant recommendations for the modifications that were made.

It should be noted that the current specifications listed above are nearing replacement and are expected to be superseded by API SN and ILSAC GF-5 rated oil in late 2010. Eric Lai adds:

If you still have engine oil with an outdated letter rating, such as SL, it can safely be used in older vehicles where the manufacturer calls for that letter designation or a previous alphabetical designation.

If the oil rating isn’t suitable for any of your vehicles, I’d suggest putting it in an oil can for lubricating hinges or check if it’s usable in your lawnmower or snow blower.

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