Diesel Treatment

I’ve been using the STP Ultra 5 in 1 Diesel Fuel System Cleaner in my car tuning and workshop business for a while now, and it’s been fantastic. I use it on everything from standard diesel vehicles to high-performance tuning projects, and it consistently delivers excellent results. This cleaner tackles multiple issues at once — it cleans injectors, removes carbon deposits, prevents corrosion, and improves overall fuel efficiency. I’ve noticed smoother running engines, reduced smoke, and more responsive performance after use. It’s also incredibly easy to use and works with every diesel vehicle I’ve tested. Compared to other fuel additives I’ve tried, this one really stands out for its reliability and effectiveness. It’s a small investment that pays off in better engine performance, longevity, and fewer maintenance issues. For any professional working with diesel vehicles — whether in tuning, repairs, or general maintenance — the STP Ultra 5 in 1 Diesel Fuel System Cleaner is an absolute

I was skeptical at first, but this STP DPF Cleaner really impressed me. I used it on my 2016 BMW 320d which was starting to feel sluggish and occasionally throwing up a DPF warning light. After adding the full 200ml bottle to a full tank and going for a steady motorway drive, I noticed a clear difference after just one treatment. The engine feels smoother, acceleration has noticeably improved, and the DPF warning hasn’t come back since. It genuinely feels like the car is breathing easier now. I also appreciate that it’s made in the UK – gives me confidence in the quality. If your diesel car is showing early signs of DPF clogging or just isn’t performing like it used to, this is a simple and affordable solution before jumping into expensive garage visits. I’ll definitely be using this regularly as part of my maintenance routine. Highly recommend!

ExcellentProduct made big bdifferance tomhow my car ran.

Had the DPF light appear as I do a few short trips to work. Ended up disappearing after I followed the manual and went for a 30 minute drive with average speed of 45mph+, but thought it best buy this too to make sure the DPF gets cleaned through. However, it’s not a miracle cure so if you’ve neglected your DPF then don’t expect it to unblock years of soot buildup. Haven’t had the warning light return since and I’ve done a lot of short trips! Easy to pop in with a tank of fuel and seems very good value. Will buy again

I’ve used this 4 times now on my 2008 Land Rover Discovery 3 (150k miles) Each time has quietened the injectors and made the engine overall more quiet and smoother, while increasing the power, efficiency and slightly increasing the MPG. I’ll be doing it a 5th time in a couple of thousand miles and will report again.

I recently tried the STP Diesel Fuel Additive Treatment Bundle, which includes the Diesel Injector Cleaner and Ultra 5-in-1 Diesel System Cleaner. Bought it hoping to give my diesel engine a little refresh—maybe clean out some gunk, boost efficiency, or smooth things out. I followed the instructions: dumped the treatment into a full tank and drove it down to about 1/4 left before refueling again. Performance Observations: Smoother Acceleration: Noticed the biggest improvement here. Throttle response felt a touch more refined, especially when accelerating from lower speeds. No more minor hesitations or rough surges—just steady, smooth power. Low-RPM Improvement: The engine also seemed happier at lower RPMs—less grumbly when idling or cruising in traffic. No miracle transformation, but a subtle uptick in responsiveness. MPG? Nope: Unfortunately, didn’t see any measurable increase in fuel economy (which was my main hope). Maybe over multiple treatments? Or my expectations were too high. Subtle Changes: If you're expecting a night-and-day difference, this isn’t it. The improvements were there but minor—worth it if you’re after maintenance, not a power overhaul. No MPG Boost: A bummer, since cleaner systems should help efficiency. Maybe mileage varies depending on the engine’s condition. Final Verdict: Solid for routine maintenance, especially if your diesel’s feeling a bit sluggish. It delivered on smoothing things out and added a hint of pep, but don’t expect drastic fuel savings. If you’re proactive about injector health, this is a good preventative product—just temper expectations for instant miracles. Rating: 3.5/5 – Does its job, but won’t blow your mind. (Would’ve been 4 with even a tiny MPG bump!) Made in the UK for anyone who cares about origin—no complaints on quality there.

Did the job perfectly. I have only used one of the bottles so far. My diesel engine started running a bit rough and felt like she might cut out when I was stationary at junctions. She's an old Kia Sorento. I figured before I booked her in for exploratory work, I'd add the bottle to my next tank of diesel and it worked. One day, when I put my foot down hard, I could see a puff of black smoke come out of the back of the car (after I'd used this additive) and have not had a problem since. I think it cleared whatever gunk was in the fuel system. I'll be using the second bottle in about 6 months time. I used the Diesel Injector cleaner first. I'll use the Diesel System cleaner next. Good price and super fast delivery. I've only used the injector cleaner so far and driven around 100 miles but the fuel economy has definitely increased and the engine noise has gotten quieter so i'm happy to recommend.

Ive been having problems with white smoke coming from my vauxhall zafira diesel on start up and on short journeys , could even smell smoke In the cab at times , also had a glow plug warning light , took it to the local garage who said I had a problem with one or more diesel injectors ,said it could be a strip down job , lots of time and money , were reluctant to even work on on it !! bought this STP Diesel injector cleaner added it to the tank and the results were almost instantaneous, no smoke on start up , no smoke while driving and the warning light has gone out ! car is also running much better , its Day 5 now and everything still ok , well worth a try ! it worked for me !