STP Ultra 5 in 1 Petrol System Cleaner 400ml, Restores Power and Protects your Engine, Enhances Fuel Economy, Mechanical Car Cleaning Products, Concentrated Cleaning Formula, Made in the UK

Arrived quickly from Amazon, we'll packaged. Put this in a full tank on my 2015 1.2 petrol DS3 w/103k on the clock about 2 weeks ago and so far looks good. My fuel gauge is digital and each quarter is split into 3 blocks, since I bought the car 2 1/2yrs ago I've been gauging fuel use by using the trip computer, trip 1 for each block and trip 2 for full tank, each block was going after about 28 miles, 30 at a push, so each quarter tank gave about 84ish miles, so a full tank was returning about 350 miles, my journeys are very much the same month to month, home-work-home, shopping or popping to MILs. Since I've put this in 2 weeks ago each block in the quarter of the fuel guage has been going off after 35 miles, so 105 per quarter so possibly signifying an increase of 70 miles or so for the full tank.Now in February I did have new tyres all round and a wheel alignment so the new fuel economy could be partly down to that but I have felt that the throttle response does feel much better, I've got this on subscription so planning to put this in my car and the wife's every other month and see how it goes but at first impressions it looks to be doing something positive

Really improves engine performance, I used the product in a 7 year old Citigo and it has improved acceleration and has made the engine even smoother. I will be using again and I would recommend. Easy to use just pour into the petrol tank.

Updated review. In summary it helped low-end performance but did not improve fuel economy for same *driving style*.Do these cleaners work? This is an emotive subject but unfortunately like most people I am not trained in stripping down and rebuilding the engine in my car! So let's look at this idea about deposits another way - burning hydrocarbons makes deposits, so would you not get your home gas boiler cleaned and serviced to keep it working efficiently?I have a 2009 Kia Rio 1.4L petrol on 60k miles, the engine is a simple DOHC 16v unit with a cast iron block. I chose this product because the datasheet indicated that it is x5 more 'concentrated' than the equivalent Redex, so this was essentially the same cost versus 'cleaning power'. During the past two years I have occasionally used Redex and I am certain it has improved the engine's response and the fuel consumption, but exactly how much I don't know. The only issue I have had with this product is with dosage, the bottle label contradicts the products US website, so I used 50% bottle in 9 gallon (imp) tank. After one tankful I would say it has helped low-end performance (up to 3k rpm) but did not improve fuel economy for same *driving style*, I think the economy gain is cancelled because you inadvertently continue to use more throttle for the same rate and so use more fuel, so maybe I'll try to accelerate with less throttle and see if I get an improvement. I think next time I will try either Techron or Seafoam.At the end of the day I see this as a one-off preventative measure on a car that I put £150pcm worth of petrol into, it may be that my 10-mile commute and occasional 'Italian tune-up' are ideal in reducing the build-up of deposits.

Easy to use,and it really does improve your vehicle’s performance.I drive a 2008 Insignia and after using this product I certainly noticed an improvement in acceleration and fuel consumption.Also my engine was running noticeably quieter.All in all a good product.

Bought this for my 21 Yr old Honda Civic (petrol) with 144k miles on the clock...I usually bung some redex in once a month, which keeps it ticking over nicely, even tho I have to pay extra for the expensive 97RON fuel as it runs like I'm towing a caravan if I use the cheaper stuff. It had started hiccuping on acceleration from time to time, so I thought I would try this instead...what a difference it makes! Filled it 3/4 full then put a bottle of this in...within 5 miles, the old zip on acceleration was back again, have had zero hiccups from the car, its quieter on acceleration and I would guess (haven't compared) it uses less fuel now its cleaned the entire system...I have added a bottle of this to my subscription list for every 2 months, and have the same brand bottle for "high mileage vehicles" in the months in between...I usually blow out the cars cobwebs with a long uphill sprint to get onto the M25, but after using this, I was astonished how smooth the pickup was, and how easier the car revved...give it a go :)

Seems to be doing its job