Product of the Year 2020 – Best Car Shampoo

Best Car Shampoo 2020 / 2021 (Review & Buyer’s Guide)

I’ve tried quite a few really great quality shampoos this year, but when I had to pick my favourite, Garage Therapy ONE: Car Shampoo instantly sprung to mind. Here’s why it got my vote for shampoo of the year!

GT / ONE: Wheel Shampoo and / ZERO: Decontamination Shampoo also deserve a special mention in this post (more on both later!). However, I wanted to pick my maintenance shampoo of choice as I thought that’s what everyone would most likely want to read about when considering the “best car shampoo” .

garage therapy car shampoo
garage therapy car shampoo

Slickness and Suds

I’ve tried shampoos in the past that haven’t got this balance dialled in properly, but the way this product feels on the panels is spot on for me. If I had to choose just one word to describe basically every GT product I’ve tried, the word would be “slick”. It’s a very important characteristic to have in a shampoo in particular, as it just makes the contact wash much safer and really helps reduce the risk of swirl marks.

It also foams up very well and gives you plenty of suds in the bucket, even with a pretty low dilution ratio. Now I know that suds don’t really equal lubrication, however, for me it’s important in a shampoo and makes it feel more enjoyable to use. The suds also stick around as the stability is really great. I actually forgot to empty my wash bucket one time, and about 15 hours later the shampoo looked the same in the bucket as when I started!

Dilution Ratio

The instructions say to use 20ml in a 4-5 gallon bucket (roughly 20 litres), making it around a 1/1000 dilution ratio. This may not seem particularly impressive, as I have seen dilution ratios of close to 1/2000 on other automotive shampoos. However, I think it’s quite a conservative ratio to state on the bottle. I usually use a bit less than this and the suds and lubrication are more than enough. Personally, I use about 10ml in my wash bucket, keep in mind though that my car is pretty small, so I only use about 15 litres of water.

It’s worth noting that GT say on the website that they’ve had great results from using 10-15ml, but have put 20ml on the bottle, as this will be suitable regardless of external factors such as water hardness. So, give it a go with a lower dilution ratio and see how you get on.

Cleaning Power

I always do a thorough prewash on the car before I move onto using the shampoo, so I can’t say that I’ve tested it rigorously on a filthy car. However, it did everything I asked it to in terms of cleaning ability and left a lovely finish behind. So, there’s not too much to say in this section, but I think it’s still important to mention it!


I just wanted to quickly mention how easily this product rinses off the panels. It doesn’t mask coatings, waxes or sealants and just leaves a clean surface behind. This is really what I look for in a shampoo, as I always tend to reach for “pure” rather than “gloss-enhancing” shampoos, as I prefer the boost in gloss and protection to come from either a wax, sealant or QD instead.


So if you go with the instructions on the bottle, and use 20ml per wash then here’s how the prices work out at the time of writing this.

– 500ml bottle = 40p/wash (£10 bottle)

– 1 litre bottle = 34p/wash (£17 bottle)

– 5 litre bottle = 16p/ wash (£39 bottle)

In reality, when I use 10ml, the cost per wash is around 20p which is pretty good going!

Extra Notes

Here’s a few more observations I wanted to touch on before I wrap this up.

– It can also be applied to vehicle car using a foam lance due to it’s high foaming ability.

– The shampoo has a very nice berry scent which really comes through when you’re washing the car.

– The only thing I would like to see to improve this product slightly, is maybe a flip cap or pump to dispense it to make measuring it out a little easier.

Final Thoughts

So why’s it my favourite then? Well, it does every right in terms of cost per wash, dilution ratio, cleaning ability, scent etc. But what stands out for me in particular, is how safe it feels on the paintwork. It has plenty of suds, which again for me is important, and the consistency really helps the mitt glide along the paintwork. In summary, I feel very confident using this shampoo on my car, especially in winter to reduce the chances of scratches during the contact wash process.

This is just one of the shampoos in the GT range. I’ve also tried / ZERO: Decon Shampoo, and / ONE: Wheel Shampoo. Both are exceptional products, however I chose / ONE: Car Shampoo to talk about as I wanted to go for a classic pH neutral car shampoo as my product of the year.

I’d probably say that / ZERO: Decon Shampoo has been my favourite product of the year so far because it offers something a bit more unique and has really changed the way I approach the decontamination process, and dealing with my family’s filthy cars!

I also never really thought I’d need a dedicated wheel shampoo until I tried this one. It again, has changed the way I approach cleaning my car. I now would really struggle to find a better way to clean the alloys other than using this.

GT Car Shampoo and Wheel Shampoo were very kindly sent for free by GT, however I wasn’t obliged to review either of them, I just feel like they’re amazing products that deserve plenty of recognition! Decon shampoo was the first GT product I bought, and I was really blown away by it and couldn’t wait to try more of the range.

Special mentions to the rest of my top 3 shampoos I’ve tried this year:

Pyramid Car Care Ultra Shampoo

Car Chem Super Suds