Do BG 44K, 244 and 245 Work? What a Fuel Cleaner Can Fix

Hesitation, a rough idle or a diesel that has lost its pull can all come from deposits in the fuel system. Pour-in cleaners such as 44K for petrol and 244 or 245 for diesel are designed to dissolve them, so they help when deposits are behind the symptoms.

The Oil Additives range at PartsForMachines lists over 320 products from BG, Exocet and Fortron, including the 44K, 244 and 245 in sizes from 100ml to 946ml.

Do Fuel System Cleaners Like 44K Actually Work?

They can, when deposits are causing the problem. Fouled injector tips can restrict fuel flow and distort the spray, costing power and efficiency. BG says 44K reduces surging, misfiring, stumbling, hesitation and lost power caused by deposit build-up.

It is formulated to dissolve deposits right through the fuel system, from the injectors and fuel filters to the combustion chambers. If a petrol engine’s symptoms point to dirty injectors, try the 44K petrol fuel system cleaner (208E). If deposits are not to blame, no cleaner will cure it, so have the fault checked.

Does a Direct-Injection (GDI) Petrol Engine Need a Different Cleaner?

Not for the injectors: 44K is designed for both GDI and port-injected petrol engines. The difference lies at the intake valves. A GDI engine sprays fuel straight into the cylinder, so fuel no longer washes the backs of the valves, and oil residue can build up there and bake into carbon.

That carbon is tackled through the air intake. The 260E air intake and valve cleaner is designed to remove heavy deposits from valve backs on GDI and port-injected engines. It is used only with dedicated supply tools and adaptors, though, so it is a garage job.

244 or 245: Which Diesel Cleaner Do I Need?

Use 244 for routine care at fill-up, and 245 where heavier injector deposits or symptoms are the worry. Both target deposits inside common rail injectors. Heat, high pressure and very fine clearances mean deposits there can make moving parts stick, leading to poor running, lost power and higher emissions.

The 244 diesel fuel system cleaner (244E) is made for regular use, to keep injectors and combustion chambers clean. BG describes the 325ml 245 premium cleaner (245E) as especially effective on heavy deposits inside the injectors. It also lubricates the pump and injectors and contains a cetane improver.

In the Tank or at a Garage, and How Often?

44K, 244 and 245 all go straight into the fuel tank. A garage injector clean is a different job: on BG’s service, a supply tool connects to the fuel system and runs a professional fluid through it, such as 210E for petrol or 229E for diesel. Never pour 210E into the tank.

As for how often, follow the label rather than a fixed mileage. Add 244 at each fill-up or service for maintenance. Use 245 at major services, or sooner if the engine runs rough, loses power under load, smokes or blocks fuel filters early.

What Should I Check Before I Buy?

• Fuel: petrol (44K) or diesel (244, 245 or DFC Plus).
• Injection system: GDI or port injection on petrol, common rail on diesel.
• Tank size against the dose on the label, to pick the right pack size.
• The symptom, and whether a diagnosis points to deposits rather than another fault.
• Pour-in or professional: tool-based fluids such as 210E and 260E need specialist supply equipment, so they are a garage job.

Browse the Oil Additives range, or contact the PartsForMachines team by WhatsApp, telephone or email with your fuel type, engine and the symptom you want to sort out.

Pack sizes, delivery options and returns terms are shown on each product page. A 30-day return policy applies to eligible items.

Frequently Asked Questions

Can I put 44K in a diesel engine?

No. 44K is a petrol fuel system cleaner. For a diesel, use 244, 245 or a DFC Plus treatment, which are made for diesel fuel systems, common rail included.

Is 44K safe in an older or classic petrol car?

44K is safe in any petrol engine, including turbocharged, GDI and port-injected ones. For a classic, especially one on carburettors, check the label or send us the engine details first.

Will a fuel cleaner harm my turbo, DPF or catalytic converter?

BG states that 44K will not harm a turbocharger, and it is compatible with catalytic converters and oxygen sensors. 244 and 245 are safe for catalytic converters, DPFs and oxygen sensors, and contain no alcohol.

How much petrol does a bottle of 44K treat?

One 325ml bottle treats a full tank: pour all of it into a full tank of petrol and drive as normal. The 100ml can treats 19 to 38 litres.

How much diesel do 244 and 245 treat, and what about a big tank?

Dose by volume. 325ml of 244 treats 38 to 60 litres, and the 946ml workshop size of 245 (24532) treats 75 to 150 litres. For lorry and plant tanks, scale up using the per-litre ratio on the label.

Will a fuel system cleaner improve my fuel economy?

Only the economy that deposits have taken away. 44K is made to restore fuel efficiency, and 245 to restore power and efficiency lost to deposit build-up, so any gain depends on how much deposits were holding the engine back.

My diesel failed its MOT emissions test: will a cleaner get it through?

Only if injector deposits are part of the cause. Internal injector deposits can push emissions up, and those are what 244 and 245 target, so have the fault diagnosed before the retest rather than relying on a bottle.

My diesel’s fuel filters keep blocking: can a treatment help?

It can: DFC Plus HP Easy Treat (2426) is designed to prevent black fuel filter plugging on common rail diesels and to improve cold-weather performance. It goes in at each fill, so fit a new filter first if one is already blocked.

Is an engine flush like EPR safe on an older engine?

Yes, unless it has excessive sludge. The EPR engine treatment (109E) is made to be harmless to seals and engine parts in petrol, diesel and rotary engines. It targets fuel gums clogging the piston rings, not oil sludge.

When does EPR go in, and how long does it run?

Just before an oil change. Add it to the oil, bring the engine to full temperature and run it for 10 minutes at 1,200 rpm, or at least 20 minutes on GDI engines and small passenger diesels. Then drain, fit a new filter and refill.