Q: I have a 2010 Nissan Sentra 2.0-liter. My "Check engine" light came on and the code indicated that my variable valve timing solenoid was the issue. It had been about 6,000 miles since my last oil change, and when I was braking, the oil light was coming on, telling me I was due.
I then noticed my typical 25 miles per gallon was down to 20. I went to get an oil change, as I read that low oil or very dirty oil can cause the VVT code to light up.
The light did indeed go off after a day or so, and that same day I ran to the emissions center to have the car checked. It passed the inspection, but since then, my MPG has been staying at around 18-19.
Any suggestions on what I can do to boost the MPG back up to about where I was?
G.A., Lake in the Hills, Ill.
A: The first thing we would do is zero out the MPG history in your car's memory. Start with a clean slate and you may find that your current fuel economy numbers are better.
Keep in mind that most cars' fuel economy is poorer in areas where winters are cold. The fuel blend is a primary reason, but heavy use of power-robbing accessories such as the heater, wipers, rear defroster and so forth also have an impact.
Q: When a tire is mounted, is it put on a wheel or a rim?
D.N., Tinley Park, Ill.
A: The terms are pretty much interchangeable.
For instance, we talk about buying alloy wheels or alloy rims, but if you need to be exact about it, the rim is the outer circumference of the wheel to which the tire is mounted. The inner section, with the holes for attaching it to the car is technically the wheel disk. Wheel and rim are essentially synonymous.
Q: Your recent column included a question about heated dipsticks.
This brought back memories of living in Anchorage, Alaska, for two winters. When it got down to 35 below (before windchill), I used a bush pilot trick of draining the oil upon returning home, then heating the oil in the oven before driving again.
The engine always ran well, but the wife wasn't happy when she baked next time. I always enjoy your columns.
B.M., Wilmette, Ill.
A: I had never heard of that trick, but I am sure it works. I wonder if a microwave also would work, or if it would set the oil on fire! To keep the peace at home, perhaps you should have invested in a crappy used oven to keep out in the garage for oil heating.
By the way, our neighbor who has a home in Anchorage just dropped off a fresh blueberry pie to thank us for plowing her driveway.
Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician.