Rust can build up on your metal car wheels rather easily, especially if you end up keeping it idle for a while. Rust can especially build up in the crevices around the spokes where light doesn't get in and water can build up. If you're someone who likes to keep up your car's appearance, this can be a major problem. The difficulty in cleaning the rust off depends entirely on how much has built up on the wheels.
Wash and dry the entire surface of the wheels; a garden hose can work best. Clean off all dirt, pollen, brake dust and anything else that might be on the wheels until there is nothing but the rust itself on the rims.
Scrub the surface of the wheel with a wet scrubbing pad, then wash off the wheel's surface with warm water. If you don't get all the rust off this way, apply aerosol oil such as WD-40 to the surface and wipe off as much of the rust as you can with either a rag or the scrubbing pad. If you put enough effort into it, you might be able to get all the rust off.
Use naval jelly on any rust that is not yet removed. Apply the jelly to a cloth and rub the jelly into the rust with the cloth. Apply the WD-40 once again after scrubbing, and wipe the wheel with a fresh cloth.
Try an all-purpose cleaner that is more concentrated and acidic than most cleaners. Spray the cleaner liberally onto one section of the wheel and let it sit for about 30 seconds before wiping it off. Don't let the cleaner sit for too long, because it can possibly damage the wheel itself.
Switch to a harsh, abrasive material to scrub away any extremely tough rust. Steel wool or a wire brush can work with plenty of water on the wheel's surface; you can also use a crumpled ball of aluminium foil soaked in soda pop. Wash the surface with clean water after scrubbing.
Applying another coat of WD-40 after removing the rust can help prevent more rust from developing; however, it can also make your wheels look dull.