Liqui Moly 5156 Pro-Line Diesel System Cleaner 500ml

Great products as usual .

I’ve driven my Mercedes A-Class from 22,000 miles to 106,000+ and always took care of it, but recently noticed the engine felt a bit lazy, especially on cold starts. Decided to give Liqui Moly Diesel System Cleaner a try — and I’m genuinely shocked by the results.I added one full can to 20L of diesel, then did a proper long motorway run (20miles) using higher revs (2,500–3,000+ rpm) to let the cleaner work its way through. Within the first 100 miles, I noticed smoother idle, better throttle response, and a more eager pull — especially at low to mid rpm.The real kicker?My commute MPG jumped from an average of 37–42mpg up to 52.7mpg — the highest I’ve ever seen in years of driving the same route!It’s like the engine’s been freed up. This stuff clearly cleaned up the injectors and combustion system because the car feels noticeably lighter and more responsive.Will absolutely be using this every 6 months as part of regular maintenance.Highly recommended for any diesel owner — especially high mileage cars.

This treatment did make a difference especially with reducing smoke. As I have not used any kind of treatment in the last few years I think I need another treatment and then use annually when servicing.

I used to use BG products in my bmw 120d but it’s hard to get now, I found this liqui Moly after a bit of hunting and reading a lot of reviews. I only used half a can in 60 Lts of fuel to start with but within a few miles it was working, it felt a bit more responsive now after a few tank fulls of fuel it has pushed up the mpg from 49 to 54 around town. I have also used there engine flush and I am very happy with that to 👍

I used the product on a Mercedes B Class W245 2008 180Cdi. The car was not pulling as it used too and fuel consumption was higher. After adding the Pro-Line Diesel System Cleaner to a full tank and drove around 25 miles the engine started to be a little bit smoother and you could feel the car pull properly when accelerating. The engine sound is better as well and the mileage improved from 32 mpg to 41 mpg. So, I am very happy with the product.

Good product!

Managed to pass my MOT after Fail cos of emissions used this product in my 3 series BMW, emissions decreased noticeably, also noticed quite big improvement on MPG, from 35MPG went to 42 MPG, engine sounds better and feels that accelerator responding much quicker.

Works as stated , I will be using this from now on.