If your leather steering wheel is shiny or slightly sticky, you need a good cleaning. If it is also a bit faded, that can be refreshed as well. See this post for detailed instructions.
Visit Colourlock.com and buy a Leather Fresh kit for your vehicle. They color match most OEM leather. You’ll want to also get a scrub brush and a sanding pad. If your steering wheel is in really bad condition, also get some leather cleaning spirit. All in, you might spend about $100, but compared to a new steering wheel, that’s a bargain.
Start by masking off the trim. (If you’re black trim is also in bad shape, consider recovering it with 3M film.) You won’t make a huge mess, but you do want to cover the instrument cluster and your lap. Wear gloves. The chemicals are not harsh, but they will dry out hour skin.
Start by using the cleaner and the brush. You’ll want to clean the entire steering wheel a couple of times. Keep cleaning until you don’t get any discoloration on the towel you use to wipe it off. If the wheel is in really bad condition, use the leather cleaning spirit as well (in a well ventilated area.) Once dry, lightly sand the entire wheel, paying special attention not to sand the stitching or sand too much. You just want to rough up the surface and knock down any imperfections. If you wheel has been refinished before, take special care not to sand too much, especially if it is a heated wheel. When finished, clean again with the leather cleaning spirit. Let dry.
Leather Fresh is a leather dye that dries quickly to a matt finish. Work a small area at a time and dab it on with the sponge, don’t paint it on. Use a heat gun on low or a hair dryer on high to dry the dye. It can be handled as soon as it is dry, but wait 24 hours before applying any protectant. You’ll want to apply 2-3 light coats over the entire wheel and more where it was heavily faded. Give yourself about an hour for the entire project.