Some cars have a light that comes on. Some have an attention-grabbing tone. Other, older models just quietly sneak into the red zone. All have a needle pointing ominously to “E.” We’re talking about the “Low Fuel” warning. We’ve all been there. During a busy day, it’s easy to neglect that stop for a fill-up. Many times, we think it can wait: “Oh, I can go another 50 miles, easy,” we think. Maybe yes, maybe no. The fact is that some mechanics say you should always keep at leas