Washing your car involves tackling the grime with a quality selection of cleaning products, one of which should be the best pre-wash. This miracle chemical is designed to tackle the worst offending muck on a vehicle – and we’ve put some pre-washes through a thorough test.
These chemical sprays work to soften and dislodge big bits of dirt, soaking them so they can be easily rinsed off with water. They are then broken down enough to be safely removed with a wash mitt. The reason for doing this is to prevent scratches, as you won’t need to use your wash mitt to tackle hardened contaminants that may then be dragged across the paintwork.
Pre-wash is both an umbrella term for a whole host of products you apply to your car before the shampooing process and a stand-alone product. Pre-wash includes snow foam, all-purpose cleaner (APC), insect and grime remover, traffic film remover and, rather confusingly, citrus pre-wash.
The best pre-wash tested 2024 at a glance:
The best pre-wash: Car Gods 54 Pre-Wash – buy from Amazon
Editor’s pick: Auto Finesse Citrus Power Pre-Wash – buy from Amazon
Best spraying tool for cleaning products: Autoglym Easy Sprayer – buy from Amazon
How we tested the best pre-wash
We tested a selection of citrus pre-washes on one of the most challenging test subjects we’ve ever used. A 1982 Audi 80 that, at the time of writing, hasn’t been on the road since 1996. It was covered in all manner of moss, grime, and dirt that had accumulated over time due to bad storage, neglect and all the things you’d expect from an abandoned vehicle. Each product was applied according to the instructions printed on the bottle, agitated if instructed, and then rinsed away.
What we look for in pre-wash
We were looking for cleaning ability against the manner of grime, including moss and algae. The best would effortlessly lift these when rinsed away. We also looked at the value for money and scent. A dilutable product would score well if it remained useful, while a pleasant citrus smell was desired.
Verdict
I was bowled away by just how effortless the Car Gods 54 pre-wash was for cutting through grime without issue. Point and spray at any piece of dirt you come across, and it will lift it, no questions asked. It’s also hard to ignore the value presented by the ValetPRO Citrus Pre-Wash Cleaner. If you have a pump sprayer to hand, it really does make a lot of sense.
The best pre-wash tested 2024
The best pre-wash
The product could deal with any level of dirt, from a mucky fuel filler cap to years' worth of moss on the bonnet and boot lid. We liked it so much that when the test ended, it was the pre-wash of our choice, and we had to crack on with cleaning the car properly. If you're shopping around for a pre-wash that suits all kinds of paint and dirt, you really shouldn't be looking any further.
Pros
- Top-rated cleaner and our overall favourite
- Features corrosion inhibitors
- Fights dirt and grime very thoroughly
Cons
- Not designed to be diluted
- You need a few sprays to make it really effective
| Volume | 1L |
| Suitable for | All exterior surfaces |
| Curing time | 5-minutes |
| Application | Spray-on |
Editor's pick
We found that with the same level of agitation as the others, it did light work of the top layer of dirt and grime that was on the tested panel. We also tested it on the inside of the fuel filler cap, and it removed a very thick layer of dirt there, too. We were impressed by its capabilities, but it didn't quite stretch to impress us as much as the Car Gods pre-wash.
Pros
- Simple to use and clean off
- Perfect for insects and grime
- Takes a thick layer of dirt clean off
Cons
- Doesn't get every last freckle of dirt off
| Volume | 1L |
| Suitable for | Exterior surfaces and engine bays |
| Curing time | Several minutes |
| Application | Spray-on |
The best pre-wash to be diluted
We applied this down the side of the Audi, and we found it to be just as effective as the Car Gods Pre-Wash, albeit not quite as powerful. We found that it needs more agitation with the detailing brush in order to achieve the same effect, whereas the Car Gods product needs less so. But when you consider that it's a little bit cheaper per litre, it's a very decent product for what it is and should suit most detailers.
Pros
- Great value for money
- Effective cleaner
- Very strong stuff
Cons
- You'll need a spray bottle to apply it
- Requires a tad more agitation
| Volume | 1L |
| Suitable for | Bodywork and wheels |
| Curing time | Several minutes |
| Application | Diluted 1:8 |
The best all-purpose cleaner (APC)
Sadly, the answer is not so. We sprayed over the same area a few times and agitated as thoroughly as we could, but the product isn't strong enough to remove the heavy dirt that accumulated on the Audi. Granted, most uses of the APC won't be to perform a full deep-clean of an abandoned '80s classic, but based on its performance in our test, it doesn't stack up to the other products we tried.
Pros
- Ideal for quick sprucing-up
- Can be used for all sorts of bits on a car
- Good value
Cons
- Isn't really as suitable as pre-wash
- Won't clean a heavily dirty vehicle
| Volume | 1L |
| Suitable for | All surfaces, inside and out |
| Curing time | None |
| Application | Spray-on |
The most efficient pre-wash
We found that it made a great effort at removing the moss, algae, and grime with the help of the pressure washer. But the panels it was tested on (the bonnet and roof) were the hardest to get clean. It required a lot of effort and agitation to clear the top layer of muck, but especially when you consider the product was diluted rather than directly sprayed on, we were impressed at how much it contributed to the end result of a squeaky-clean Audi.
Pros
- Deals with a lot of really bad dirt
- Works well when diluted and sprayed
- You don't need too much for it to work
Cons
- Not as convenient as spray bottle
| Volume | 500ml |
| Suitable for | Bodywork, engine bay, wheels, wheel arches |
| Curing time | 2-3 minutes |
| Application | Spray-on or diluted |
We weren't expecting much, upon initial impressions, we expected it to last about ten seconds when spraying and for it to be a bit of a novelty. However, we were proven wrong. You have to pump it several times before you feel a weight of pressure, but once you begin spraying, it's very akin to a handheld spray gun. It has a very consistent flow and is more powerful than you'll expect. It helped spread an even layer of pre-wash on some panels and is a very useful item to have as part of your car cleaning kit. The build quality wasn't bad either - and it isn't heavy when you fill it to the brim.
Pros
- Great quality item
- Spreads an even layer of product at a healthy flow rate
- Doesn't take much effort to pump
Cons
- You won't need it if you use spray bottled products
FAQs and what you need to know about pre-wash
What to look for in a good pre-wash?
Dilution – A very important thing to consider. Many pre-washes are designed to be diluted to suit your needs. This can range from strong degreasing right down to light dust removal depending on how much water you add. This makes even a small bottle exceptionally good value for money but does mean you’ll need to get busy with a spray bottle. For dirtier jobs like removing grease and oil, a good degreaser should do the task.
On the other hand, ready-to-use spray examples are way more convenient and will still do the vast majority of tasks. You just won’t be getting as good bang for your buck.
Citrus oils – The central part of any good pre-wash is whether it contains citrus oils or not. These oils are excellent natural cleaners and make the product far more effective. They also give the product a nice orange scent, very pleasant.
What’s better, snow foam or pre-wash?
The purpose of snow foam in its best form is to perform exactly the same job as we did with the detailing brush with the pre-washes. To agitate the pre-wash, which in turn, makes it easier to rinse off afterwards. Some manufacturers will combine pre-wash with snow foam to effectively skip the first step, cover the car in snow foam while simultaneously lifting up the top layer of dirt.
We have found that pre-wash on its own is a more effective cleaner. The chemicals within are stronger to make up for the fact it won’t cling as well to the paintwork. Finally, it’ll be far easier to rinse away before attacking the body with a wash mitt. We ended up doing so afterwards, giving the body a thorough wash with a couple of top-end shampoos, a mitt, and alloy wheel cleaner. The end result simply couldn’t have been possible without all the pre-washes, which goes to show how effective they really are.
Snow foam on the other hand is gentler thanks to the longer dwell time, It also looks a lot cooler applied to a car, creating a nice thick blanket of foam.
Is pre-wash worth it?
If you’re about to embark on a heavy de-greasing job on either your bodywork, engine bay or other, pre-wash is absolutely worth it. It helps lift the worst of the dirt on a vehicle before you can tackle the different areas properly with a good car shampoo.
It helps you get the worst bits off your vehicle without potentially spreading said dirt over other parts of the bodywork, which is never a nice thing. Because all you need to do is spray, brush, and rinse, it’s a nice contact-less method of car cleaning with minimal risk of scratches.
Aaron Hussain is a commercial content writer at Bauer Media writing for Parkers and CAR. He is obsessed with classic cars and anything with a fascinating story to tell.
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