Fuel Additives

What fuel additives are for, and when they are not enough

These products help clean injectors, fuel lines, and mildly contaminated emission components such as the DPF, EGR and turbo, often improving idle stability, cold starts and sometimes fuel use and emissions. They are formulated for modern engines, including Euro 6 and Euro 7 with DPF, GPF, turbo or hybrid systems, and they are most useful under city and short-trip conditions where deposits build up fastest. What they cannot do is equally important to understand before you buy.

What these products can do

• Clean injectors and fuel system passages of light to moderate deposits
• Support DPF, EGR and catalytic converter function by reducing soot build-up
• Improve idle stability, throttle response and cold-start behaviour
• Reduce exhaust smoke if the cause is deposit-related combustion
• Help slightly reduce tailpipe emissions before an MOT if the issue is mild and deposit-related

What they cannot do

• Repair heavily clogged or electrically defective injectors
• Fix a cracked or ash-overloaded DPF
• Resolve turbo problems caused by worn bearings or damaged blades
• Clear fault codes caused by mechanical or sensor failures
• Replace scheduled servicing, oil changes or filter replacements

If a warning light remains on after one complete treatment, or if you experience misfires, heavy smoke, metallic noises or significant power loss, stop using additives and have the car diagnosed by a garage.

For a diesel driver with light symptoms and no confirmed mechanical fault, Lindemann Total Care Diesel 1L is a logical first step. For petrol, Lindemann Total Care Petrol 1L covers the same approach: one intensive treatment before you decide whether a garage visit is needed.

Which type do you need: petrol or diesel, cleaner or treatment?

You can use the same additive in more than one car, as long as the fuel type and compatibility match: check E10 or B7 suitability and whether the engine has a DPF, then dose per tank as the label states.

Diesel cleaner vs DPF cleaner: are these the same? No. A diesel cleaner targets injectors and the combustion area. A DPF cleaner supports the filter's regeneration process. They address different parts of the system and should be used in separate tanks, not together.

Full-system cleaner vs maintenance product: which one?

For rough idle or hesitation, a full-system cleaner is the better first step. For ongoing prevention when the car runs well, a lighter maintenance cleaner is sufficient.

Are fuel additives safe for your engine?

The products in this range are suitable for petrol engines running on E5 or E10 and diesel engines on B7, covering Euro 6 and Euro 7 engines with DPF, GPF, EGR, turbo or petrol-hybrid systems. Used at the correct dose, they are designed not to harm injectors, fuel pumps, catalytic converters or particulate filters. High-quality additives used as directed do not normally affect a manufacturer's warranty, though they supplement correct servicing rather than replace it. For direct injection (GDI) engines specifically: these products are safe for the fuel rail and injectors, but their effect on intake valves is limited because those valves are not fuel-washed. Deeper guidance on direct injection maintenance is available in the Knowledge Center.

Exclusions and limits:

• Not suitable for LPG-only or CNG fuel systems
• Cannot fix or reverse physical damage: cracked DPF, melted catalyst, broken turbo, damaged injectors
• Not a legal means to remove or bypass emission systems such as DPF, catalyst or EGR

E10 compatibility is covered for all petrol products in this range. If you drive an older car that may be more sensitive to ethanol, or a car that stands unused for extended periods, there are dedicated products for E10 protection and fuel stabilisation. Detailed material compatibility guidance for older vehicles is covered in a separate E10 guide in the Knowledge Center.

How to use a fuel additive: dose, timing and frequency

1. Check that the product matches your fuel type: petrol (E5 or E10) or diesel (B7). Do not use a petrol additive in a diesel engine or vice versa.
2. Check the bottle for the tank volume it covers. Follow the label exactly; never exceed the stated dose per litre.
3. Add the product to the tank before refuelling, so the incoming fuel mixes it evenly throughout the tank.
4. Fill up to the volume indicated on the bottle, then drive normally. Give the product one full tank to work before assessing the result.

Using more than the recommended amount does not improve the result and can disturb combustion or affect fuel lubricity. Stick to the label.

Can I mix fuel additives, and what about combining products?

As a general rule, do not combine multiple strong cleaners in the same tank. A diesel cleaner and a DPF cleaner, for example, address different parts of the system and should be used in sequence across separate tanks, not simultaneously. Some combinations, such as a mild maintenance cleaner alongside an octane booster, may be possible, but only if the manufacturer explicitly states this on the product page. If no compatibility note is present, treat each product as a single-tank treatment and wait until the next fill-up before using a second product.

How do you know if a fuel additive has worked?

Most drivers notice smoother running or a quieter idle within one full tank after treatment. Cold starts may feel more consistent, acceleration more even, and in diesel engines, startup smoke may reduce. These are the most reliable signs that the product has had an effect.

Fuel economy improvements are possible if deposits were contributing to inefficient combustion, but they are modest and may take several hundred kilometres to become measurable. A sudden, dramatic drop in fuel consumption after one treatment is unlikely and should be treated with scepticism. If you are using a cleaner before an MOT, it can help reduce emissions slightly if the issue is mild and deposit-related, but it does not guarantee a pass.

If there is no noticeable improvement after one or at most two treatments, or if warning lights and serious symptoms remain, the cause is most likely mechanical rather than deposit-related. At that point, a diagnostic check at a garage is the right next step.

Not sure whether your situation calls for a one-time intensive cleaner or a periodic maintenance product? Start with the symptom: if the car is already running rough or showing a warning, reach for the stronger cleaner first. If the car runs fine and you want to keep it that way, the maintenance product is the sensible choice.