Car All Purpose Cleaners (APC's)

All purpose cleaners, commonly referred to as APCs, are alkaline chemicals designed to clean almost every surface on a car. They're typically used on exterior plastic and rubber surfaces like engines, wheel arches, tyres and grilles, because these porous surfaces require more effort to clean than relatively non-porous paint and glass.

It's not as simple as one size fits all, so usually you'll need to dilute a concentrated formula to suit the particular surface you're cleaning. Handily, you'll almost always find the recommended dilution ratios on the back of the bottle.

Some all purpose cleaners are safe to use on a car's interior when diluted heavily, while some brands have specific APCs designed for interior cleaning. It's important to neutralise the residue that's left behind by these alkaline cleaners to avoid staining when the surface dries, so rinse thoroughly with water or use plenty of damp cloths to wipe away the residue.

When you need something stronger than car shampoo, an all purpose cleaner spray is usually what you'll turn to next. They're effective at tackling heavy dirt build up on any surface and have the versatility of allowing you to dilute as much or as little as necessary.

An all purpose cleaner for car exteriors is also a safer, less aggressive option than a degreaser. When used in a strong dilution, APCs are capable of deep cleaning neglected parts, and can be diluted down for gentle maintenance cleaning.

Most all purpose cleaners produce a white lather which becomes discoloured as the dirt is released from the surface. That colour change is a useful indicator for when the surface is clean, which can otherwise be hard to tell on black plastic and rubber.

Benefits of using a car all purpose cleaner:

• Effective for cleaning dirty surfaces
• Versatile dilution ratios
• Safe on most automotive surfaces
• Works on many types of dirt
• Cost effective when bought as a concentrate

You'll need to scrub the surface with an appropriate brush or cloth and make sure not to let the product dry before rinsing or wiping it away. When buying an all purpose cleaner, it's a good idea to stock up on spray bottles so you can mix up a few different dilutions.

Read the bottle first, since every product is different. As a rough guide across the APCs we stock:

Neat to 1:10 for the heavy stuff. Engine bays, wheel arches, tyres and anything genuinely neglected.

1:10 to 1:30 for general exterior work. Trims, plastics, door shuts and a pre-wash.

1:30 to 1:50 for interiors and anything delicate. Most APCs are safe inside the car at this strength, but see below.

Mix into a spray bottle and label it, because a bottle of unmarked APC is the fastest way to stain a dashboard with an engine bay dilution. CARPRO Multi X, Koch Chemie Green Star and MIRCH Odin Edge all print their ratios on the label.

Yes, diluted properly. A multi purpose car cleaner at 1:30 or weaker handles door cards, hard plastics and carpets without trouble, which is why a single concentrate can cover the whole car.

Where people come unstuck is strength. An APC mixed for an engine bay will strip the finish off soft touch plastics, leave a chalky cast on vinyl, and stain the foam behind perforated trim. That damage doesn't come back.

A few products are built for this. Koch Chemie ASC is ready to use and safe across the cabin including screens, and MIRCH Zeus Fury dilutes all the way to 1:50 for interior work.

Leather is the exception. Most APCs will dry it out or strip the factory coating, so use a dedicated leather cleaner there. For everything else inside, a well diluted APC or a dedicated interior cleaner will do the job.