Dear Tom and Ray:

We recently purchased a new 2000 Jeep Wrangler with a manual transmission and four-cylinder engine. The Jeep has an "upshift" idiot light that tells you when to shift into the next gear. There is no guide about when to shift in the owner's manual. If I "follow the light," it feels like I'm shifting much too early and lugging the engine. So I just shift when it feels right (which tends to be at 2,700-3,000 rpm). Should I follow the light, or should I ignore it? -- Brit

RAY: This is a perfect application for the Car Talk "black tape" solution, Brit.

TOM: Take some black electrical tape (or write to us and we'll send you a roll of our extra-special Car Talk black tape for only $99.99), and slap a piece over the upshift light.

RAY: And then shift when it feels right. For a novice, the light might be helpful. But really, the light is only there to encourage you to get maximum gas mileage. And there's nothing wrong with that. But it encourages you to shift at the very early end of the range. And at that end of the range, there is a danger of lugging the engine, which isn't good for it.

TOM: So instead of getting 18 miles per gallon, you'll get 17. But you won't have that stupid light driving you bonkers for the next 100,000 miles. A great trade-off, in my opinion.

RAY: On the other hand, for those of you out there who don't know how to drive a stick shift at all, you might want to use the light as signal that it's now "safe" to shift into the next gear.

TOM: Or, better yet, you might want to just buy an automatic.