Pros: Pleasant smell, Gentle on alloys, Quick cleaning
As an owner of a car that produces enough brake dust to cover the entire wheels with its brown/black powder within a week's worth of driving, I need a way to quickly and effectively clean my wheels. (You see, BMW really stands for Brake dust, More Wheel cleaning...) For the job, I use a combination of the Griot's Garage Wheel Cleaner, Griot's Garage Boar's Hair brush, and the Griot's Garage 3-finger detail foam mitt. I have clear-coated alloy wheels, and this product is safe for use on almost all alloy wheels.
Brake dust is produced as the brake pads in your car wear out as it rubs against the brake discs (or rotors, if you have drum brakes). Most brake pads contain metallic compounds, and so you can think of brake dust as tiny metallic beads that cling on to the surface of your wheels. Because the brake dust can be abrasive when rubbed against the surface of your wheels, you want to take extra caution while cleaning your wheels and you want to clean your wheels as often as possible.
The Griot's Garage Wheel Cleaner has a very pleasant fruity scent, and it is a fairly concentrated solution so there is no need to use that much. The 35 ounce bottle of cleaner should last a few years for most folks, so don't be alarmed by the $10 price. It's well worth it, and it's gentle and safe on your expensive alloy wheels. BBS (a German racing wheel maker) just tested and endorsed the use of this product on their wheels, and countless owners of classic, exotic, rare, and luxury cars use them for their wheels.
Using the Cleaner
First, you will need to wet your wheels with a spray of water. Remember to do this in the shade, as you want to keep the surface of the wheels wet through the entire process. Then, spray on the Wheel Cleaner on your wheels, remembering to get the inside of the wheels. Less is more, so don't over-do it. Move on to the next wheel and do the same. By this time (about a minute or two), you can go back to your first wheel and with the Boar's Hair brush (or other similar, non-scratching yet stiff brush) agitate the wet surface to lather up the cleaners and the brake dust should easy break loose. The trick is reaching the inside of the wheels, through the spokes. For this, I use the 3-finger mitt which allows me to reach through the spokes without getting my hands cut up on the disc brake covers and metal parts around the brakes. After all the brake dust is loose, a quick rinse with a stream of water will leave a nice, shiny wheel. It's really that simple!
For easier cleaning, I recommend waxing your alloy wheels, about 4 times a year depending on your driving style and mileage. It will also lessen the amount of brake dust wanting to cling on to your wheels, as well as protect your wheels from the elements. I use the same wax I use on my car paint to wax my wheels (Griot's Garage Best of Show Wax).
As with all Griot's Garage products, this product is only available via mail-order (or on the web), and because of the nature of the shipping cost, it makes sense to order a few products all at once. I recommend getting the Boar's Hair brush and 3-finger detail mitt to complement the Wheel Cleaner.