Car batteries should be insulated
DRIVE IT FOREVER
Dear Mike:
My battery failed after four years, which I thought was a little too soon. The repair shop that installed it thought the same, so they replaced the battery with a somewhat larger one, the biggest they could get to fit into the battery tray. They also did a full charging system check.
Two years later the new battery failed, so they replaced it under warranty — but only half the cost was covered. It seems the fine print in the battery warranty says the battery price is prorated. And after two years, I was responsible for the use I had of it until it failed. They installed a new battery identical to the previous one. It lasted only 18 months. So, of course, I had to pay again.
I feel like I’m renting these batteries. What’s going on?
A: Normally, I would suggest replacing the smallish standard battery with the largest one possible. This is a textbook example of someone honestly attempting to improve something, then screwing it up. I see it a lot.
Your original battery had enough room surrounding it for a simple plastic insulating blanket. This device is intended not only to keep your battery warm on cold nights — which it does — but also to keep the battery cool on hot days.
Modern cars restrict the amount of air flowing through the engine compartment to improve both aerodynamic efficiency and economy. New engine compartments are pretty crowded. The elevated temperatures are enough to boil the electrolyte right out of the battery — hence, the simple insulator.
Installing a bigger battery means there is no room for the insulation, which translates to short battery life, especially in warmer climates. You should try to rig up some insulation for your new battery, or at least replace the giant battery with one that permits the insulator to be reinstalled.
This is one of the reasons some cars have batteries installed in the trunk instead of under the hood.
Dear Mike:
I own a 2000 Cadillac Eldorado. I noticed that although it now has 71,000 miles, the engine still uses a lot of oil. It is not burning it; I don’t see smoke coming out of the exhaust. The dealer tells me that this engine has a lot of moving parts and therefore “uses” oil, but doesn’t burn it.
What is a normal rate for a car to consume oil — let’s say, in miles per quart? I use an expensive synthetic and I get ticked off at how fast this car is going through it. I can barely make it 6,000 miles, which I consider to be a fair interval between oil changes.
A: All engines burn oil. Before I get a bag of mail from people telling me their engine doesn’t ever use any oil, listen up. Oil in your crankcase gains in volume from contaminants such as water and unburned and partially burned fuel, compensating for the amount of oil that is consumed.
Yes, emissions controls require that engine manufacturers engineer their products to use a minimum amount of oil. But, some oil still finds its way into the PCV system as vapor, and makes it past the rings and valve stem seals in liquid form. Normally, this oil is consumed in the catalytic converter, so you won’t see any blue smoke until the engine is burning enough to make the converter fail. Your usage of only 1 quart per 6,000 miles is really quite minor.
How much is too much? Manufacturers’ specs vary, but the industry standard centers around 1,000 miles per quart. Don’t think just because you’re using pricey synthetic oil that you can extend your oil-change interval. Under normal conditions, mineral oil doesn’t break down in use. It gets contaminated with dirt, water, acids and fuel, and its additive package gets exhausted. Same for synthetics, and their life span is the same.
Your car has an oil-life monitor built into the instrument panel. Follow the monitor’s intervals for oil changes.