Viewer-submitted questions for The Car Doctor:

Q: I have had two experiences when my car will not start after parking. This happened once at a hardware store, and I thought it was the key fob battery so went into the store to buy a new one. The clerk asked if my car was a Ford Explorer, which it is! He said this has happened before, so he came out and shut off the store’s neon sign and the car started right up! The next time this happened, I didn’t realize I was parked under a McDonald’s neon sign, and I could not lock the car nor start it. After we ate the car started right up so we didn’t have to the manager to shut off his sign! Have you ever heard of similar experiences? In any event, I wanted to alert fellow Explorer owners of this situation.

A: Ford and other manufacturers have put out technical service bulletins regarding electrical interference affecting the operation of their vehicles. Toll transponders, mobile phones, voltage invertors and other electronics can cause some weird issues in today’s cars. Readers, have you had unexplained issues that seem to be caused by electrical interference, ghosts, zombies, or anything? I would love to hear about it. Email me at

Q: I have a 2012 Honda Civic with 124,000 miles and it runs great. Is ZMax additive a good product to use for the engine and will it help with fuel mileage and help extend the life of the car?

A: I do not have any personal experience with zMax. Some reviews online state it is a great product, others had issues with it. I did find this article online: “The marketers of zMax automotive aftermarket lubricant additives have agreed to reimburse customers one million dollars to settle a false advertising suit brought by the U.S. Federal Trade Commission.” According to the article, the settlement, approved by a federal judge in Greensboro, NC, prohibits Speedway Motorsports Inc. and a subsidiary Oil-Chem Research Corp. from continuing to make general claims that zMax Power System improves fuel economy, reduces engine wear and corrosion, lowers emissions, and extends engine life. Personally, I think it’s best to use a good quality oil and premium or factory filter, check the oil level often and service the cooling system to prevent overheating. Also, for the first few miles when the engine is cold, take it easy and drive like it’s a brand new car to help prevent wear.

Q: Last year, after being in Florida for six months, I found my car had mold inside. It had been completely covered while I was away. Please tell me how I can avoid this happening next year when I return from Florida.

A: That is an issue, although it usually occurs in cars left in Florida, and not as much up north. I would use moisture absorber which is basically a desiccant dehumidifier. DampRid is one product, and there are others. Use several containers (one on the floor in the front seat, one on the floor in the back, and one in the trunk if it’s a sedan. Put them on aluminum pie plates in case they overflow. If you use a car cover, make sure it is both waterproof and breathable–not one that goes completely to the ground which could trap moisture in a very wet environment. Dry out and clean the car as much as possible before you put it away. Run the air conditioner for a bit to dehumidify the interior and look for water draining onto the ground. If, after 15 minutes of A/C use, you do not see water draining, the evaporator drain may be clogged and holding water which could lead to more mold.

Q: I am a weekly reader and have a question that everyone can relate. Will running my car’s air conditioner on low rather than max save me any miles per gallon or once the compressor is going does it even matter?

A: The air conditioner requires horsepower to turn the compressor, but it’s the temperature setting – not the fan speed – that affects fuel economy. Raising the temperature slightly will make the compressor run less frequently. If you have a car with automatic climate control, setting the temperature at a comfortable setting such as 72 degrees is usually optimal. That being said, the best method to save money on fuel is to go easy on the gas and brakes, watch your speed, keep tires properly inflated, and perform regular maintenance.

If you’d like more information, head to AAA Northeast.