Q: My Honda Civic has a computer that estimates remaining oil life. That usually indicates I have about 50% oil life left when I reach the mileage indicated on my windshield sticker for my next oil change. The sticker is placed there by the repair shop doing the oil change. Should I follow the instructions of the manufacturer/car computer or the repair shop/windshield sticker?
A: Your Honda, like many vehicles, utilizes a sophisticated algorithm based on engine operating conditions such as speed, engine temperature, ambient temperature, and run-time in order to predict oil life. This provides a much more accurate estimate of oil condition than miles or time alone. I try to change my oil at perhaps 20% calculated life remaining, sometimes less. 50% is doing more to pump up the service provider's bottom line than to protect your engine!
Q: When replacing your battery, can you hook up the battery charger leads to your positive and negative cables so you won't have to re-install radio settings, etc.?
A: I wouldn't recommend this. It would likely work but without the battery being present to absorb the possibly erratic electrical noise emitted by some chargers, it's possible damage or corruption could result to sensitive vehicle components or their software.
A safer alternative would be a "memory saver," a device that connects a small battery to the accessory/lighter socket, or better yet the data link connector (DLC, a sixteen terminal under-dash connector used with a scan tool for vehicle diagnosis).
Many accessory/lighter sockets aren't active when the key is off. There are also cables that connect the DLC to another vehicle's accessory socket, or perhaps one on a jumper pack. A consumer grade battery powered memory saver typically has wimpy capacity, so resist opening doors or operating anything that may wake up vehicle systems while it's in use (wait 30 minutes after connecting it and departing the vehicle before removing battery terminals)
Q: I have always loved cars and worked on them quite a bit when I was younger, mostly out of need. Last 30 years I have done well enough to drive good or great cars.
I would like to take classes and learn to work on cars in a serious manner; however, the auto schools around me are only pretty much full-time, and not much is offered in the evening. Quitting work at this stage or doing classes in the daytime is not an option.