Car Lost Power? Common Causes and How to Fix It

"My car won't accelerate like before", "the engine doesn't respond the way it used to", "my car feels sluggish"... If you've noticed your car has lost power, you're not alone — it's one of the most common complaints at any workshop. The good news is that it almost always has an identifiable cause, and in many cases it can be fixed without an expensive repair.

Why has my car lost power?

Loss of power is rarely caused by just one thing. The most common causes are:

• Dirty injectors, intake valves or carburetor due to carbon deposits.
• Fuel octane rating too low for the engine's needs.
• Clogged air or fuel filter.
• Worn or faulty spark plugs.
• Dirty or faulty sensors (such as the MAF sensor).
• Turbo or EGR system issues.

The first two are the most frequent, and they're also the ones that respond best to an additive treatment. The others usually need a workshop inspection.

Dirty injectors and carbon deposits: the most common cause

Over time, fuel and engine heat leave carbon deposits on injectors, intake valves and the carburetor. These deposits disrupt fuel spray and the air-fuel mixture, which translates into less power, slower throttle response and sometimes a rougher idle.

Octane rating too low for your engine

Every engine is designed for a minimum octane rating. If the fuel doesn't meet that level (for example, in tuned, high-compression or turbocharged engines), the engine can suffer detonation or knock, and the ECU retards ignition timing as a protective measure. The direct result is a noticeable loss of power, even if everything is mechanically fine.

Other mechanical causes that also rob power

Not every loss of power comes from the fuel. Also worth considering:

• Clogged filters: a dirty air or fuel filter reduces the flow reaching the engine.
• Worn spark plugs: poor combustion means less force and higher consumption.
• Faulty sensors: a dirty MAF or oxygen sensor can make the ECU miscalculate the mixture.
• Turbo or EGR: a fault in these systems causes a more noticeable power loss, usually with a warning light on.

These causes aren't fixed with an additive — they need a proper diagnosis and repair at a workshop.

How do I know if the power loss is fuel-related?

Some signs that point to dirty injectors or insufficient octane:

• The power loss has been gradual, not sudden.
• No warning light has come on.
• You notice hesitation, jerking, or a slightly rough idle.
• Fuel consumption has crept up slightly for no obvious reason.
• It's been a while since you used quality fuel or cleaned the injection system.

If instead the power loss was sudden, comes with unusual noises, or a warning light has come on, the most reliable option is to visit a workshop before trying anything else.

What happens if I keep driving like this? The damage of not acting in time

Driving with a dirty engine or inadequate octane for a long time isn't usually immediately dangerous, but it does have medium-term consequences: higher fuel consumption, more wear on intake and injection components, and a progressively less efficient engine. If the real cause is mechanical (spark plugs, sensors, turbo) and it's ignored, the problem tends to get worse over time.

Can I keep driving the car with less power?

Yes, generally you can keep driving normally if the power loss is mild and no warning lights are on. Even so, it's not advisable to let it go indefinitely: the sooner the cause is identified, the easier (and cheaper) it usually is to fix.

How to restore lost power

If after reviewing the points above you suspect the cause is dirty injectors or insufficient octane, a cleaning and octane-boosting additive can help restore some of the lost performance. If instead there are warning lights, unusual noises, or the power loss was sudden, the right move is to get a diagnosis at a workshop first.

NF Super Street Octane Booster: what the product sheet says

NF Super Street Octane Booster is a petrol additive (not suitable for diesel) that, according to its product sheet:

• Instantly increases the octane rating by 4 RON points.
• Contains specially formulated cleaning agents to help keep the entire fuel system clean: cleans injectors, intake valves and carburetor.
• Removes carbon deposits that cause detonation and engine knock.
• Helps restore lost power and acceleration, and reduces hesitation and engine operating temperature.
• Is safe for oxygen sensors and catalytic converters.
• Delivers excellent performance in 2-stroke engines too.
• One bottle treats up to 60 litres of fuel (one tank).
• Non-flammable, with a child-resistant cap, designed to fit directly into the fuel filler neck.

If your car is a diesel, this isn't the right product: the equivalent option in the NF range is NF Diesel Boost.

You can see all the details and buy it here: NF Super Street Octane Booster.

How to stop your car losing power again

• Use quality fuel whenever possible.
• Clean the injection system periodically instead of waiting for symptoms.
• Follow the manufacturer's maintenance intervals (filters, spark plugs, check-ups).
• If your engine is tuned or high-compression, make sure the fuel's octane rating matches what it needs.

Frequently asked questions

Why doesn't my car accelerate like before?

It's usually a combination of dirty injectors, insufficient octane for the engine, or components like filters, spark plugs or sensors in poor condition. The exact cause depends on whether the loss was gradual or sudden.

What can make a car suddenly lose power?

A sudden loss usually points to a mechanical or electronic fault (turbo, sensors, EGR) rather than a gradual fuel-system fouling issue. In these cases, a workshop visit is recommended.

Do dirty injectors reduce engine power?

Yes. Carbon deposits on injectors, intake valves and the carburetor disrupt the air-fuel mixture and reduce power and throttle response.

Can low octane fuel make a car lose power?

Yes. If the fuel doesn't meet the octane rating the engine needs, detonation can occur, and the ECU retards ignition timing to protect the engine, which results in less power.

Is it dangerous to keep driving if my car has lost power?

If the loss is mild and no warning lights are on, it's usually not dangerous in the short term. If it's sudden, comes with unusual noises, or a warning light turns on, it's best not to delay a check-up.

Does a cleaning additive restore lost power?

It can help restore some performance when the cause is dirt in injectors/valves or insufficient octane. It doesn't replace a repair if the cause is mechanical or electronic.

How long does it take to notice the improvement with an octane booster?

NF Super Street Octane Booster's product sheet states the octane increase is instant; the improvement in engine response is usually noticeable within the tank it's used in.

When does loss of power definitely need a workshop?

When it's sudden, comes with unusual noises, a warning light turns on, or it doesn't improve after trying an additive and checking filters and spark plugs.

Does losing power make a car use more fuel?

Often, yes: an engine that isn't burning fuel efficiently (due to dirt or inadequate octane) tends to use more fuel to deliver the same performance.

How do I prevent my engine from losing power again?

By using quality fuel, cleaning the injection system periodically, and following the manufacturer's recommended maintenance intervals (filters, spark plugs, check-ups).