1994 GMC Suburban Owner's Manual - Page 81

Shiff Light If you have a manual transmission, you may have a SHIFT light. This light will show you when to shift to the next higher gear for best fuel economy. When this light comes on, you can shift to the next higher gear if weather, road and traffic conditions let you. For the best fuel economy, accelerate slowly and shift when the light comes on. While you accelerate, itis normal for the light to go on and off if you quickly change the position of the accelerator. Ignore the SHIFT light when you downshift. Four-Wheel-Drive Vehicles Only: If your vehicle has four-wheel drive and is equipped with a manual transmission, disregard the shift light when the transfer case is in 4-LOW. Manual Transmissions- Shift Speeds If your speed drops below 20 mph (32 km/h), or if the engine is not running smoothly, you should downshift to the next lower gear. You may have to downshift two or more gears to keep the engine running smoothly or for good performance. A CAUTION: If you skip more than one gear when you downshift, you could lose control of your vehicle. And you could injure yourself or others. Don'tshift down more than gear when you one downshift. 2-25