RRP: from $10.74, buy it in the US here / £8.95, buy it in the UK here.

British car care expert Gtechniq knows a thing or two about detailing. We take its W1 GWash shampoo for a test wash to see how it performs.

How We Tested Gtechniq W1 GWash

First, I followed the instructions and diluted Gtechniq W1 GWash shampoo to the degree specified. Then, I tested it on one of the panels of my car, noting how much foam it produced and how it felt across the metalwork. Finally, after the wash, I inspected the panel to see how much (if any) dirt remained. The price and how much shampoo is needed per wash were also taken into consideration.

Gtechniq W1 GWash car shampoo pouring

First Impressions

I’m a fan of Gtechniq’s products and presentation. Its bottles are smart, and I like its logo, which makes you feel like you’ve got a cleaning product that’s backed by science. Gtechniq W1 GWash smells gorgeous, serving up a lovely grapefruit scent when you open the bottle. It’s a good start for this shampoo, for sure.

Gtechniq W1 GWash car shampoo foam


It’s a shampoo, that’s about it as far as features go. It is pH-neutral, though, so that’s always good. But apart from that, there’s nothing here apart from a shampoo that’s focused on cleaning performance.

What’s It Like To Use Gtechniq W1 GWash

I have no idea how big the buckets are at Gtechniq’s HQ because the dilution instructions appear to be for people who mix their shampoo in a bathtub. Gtechniq says to use two to four capfuls (06.-1.2 fl. oz), depending on how dirty your car is, in a 5.3-gallon bucket. That’s massive. You’re more likely to be using a bucket around 3.2 gallons in size. That’s still more than enough water for a thorough wash on just about any car.

Gtechniq W1 GWash car shampoo washing

With that amount of water, you’ll be using around 0.4-0.7 fl. oz per wash. That’s not bad at all, and it makes Gtechniq W1 GWash a frugal shampoo. While there was lots of foam in my container, hardly any of that transferred to the bodywork during washing. Gtechniq W1 GWash was very slick, though, and it felt lovely under my wash mitt and cleaned very well too.

The Verdict

Gtechniq W1 GWash is an excellent shampoo and another excellent offering from Gtechniq. It smells lovely, cleans well, and it’s very economical too. While it’s light on features, and you can’t use it in direct sun, it’s still a very good shampoo and a solid choice.

Have a look at the price comparisons below if you want to pick up a bottle for yourself: