Is Your Diesel Drinking More Than It Should? With Diesel Above R31 a Litre, Worn Injectors Are Costing Motorists Thousands

As fuel prices hit record highs, JEG Diesel urges motorists to check whether worn injectors, pumps or turbos are quietly inflating their fuel bills.

With diesel now costing more than R31 a litre at the coast and a further increase expected in November, South African motorists are counting every litre. But according to JEG Diesel, the fuel injection and turbo specialist that has been specialising in diesel fuel injection systems in the Western Cape since 1971, many drivers are paying for fuel their vehicles are simply wasting. 

Worn or dirty injectors, a tired fuel pump or an underperforming turbocharger can all push fuel consumption up gradually, so slowly that most owners don’t notice until the cost has already added up.

Record prices make every litre count

South Africa has endured a sharp run of fuel price increases. Inland wholesale 500ppm diesel rose from about R19.34 a litre in October 2025 to R31.95 in October 2026, an increase of around 65% in a single year. 

At the coast, 500ppm diesel stood at R31.08 a litre and 50ppm at R32.03 in October, with Central Energy Fund data pointing to another rise when prices are adjusted on 4 November. For commuters, farmers, tradespeople and fleet operators who rely on diesel bakkies, SUVs and trucks, that makes fuel efficiency a question of real household and business budgets.

How small losses add up

Even a modest increase in consumption becomes expensive at today’s prices. As an illustration, a bakkie travelling 2,000 km a month that uses just one extra litre per 100 km burns an additional 20 litres a month. At the October coastal price of R31.08 a litre for 500ppm diesel, that is more than R600 a month, or almost R7,500 a year, spent on fuel the engine shouldn’t need. For a business running several vehicles, the losses multiply quickly.

What makes a diesel engine use more fuel

Worn or dirty injectors. Injectors are designed to deliver a precise, finely atomised spray of fuel at exactly the right moment. Over time, carbon deposits, wear and contaminated fuel can disrupt that spray pattern or cause injectors to leak or over-fuel, so that fuel is not burned efficiently.

Fuel pump problems. A worn or poorly calibrated diesel pump may not deliver fuel at the correct pressure, affecting combustion and efficiency.

Turbocharger wear. A turbo that is losing boost forces the engine to work harder, and the driver to press harder on the accelerator, to achieve the same performance.

Contaminated fuel. With adulterated diesel on the rise, fuel cut with paraffin can damage injectors and pumps, leading to both higher consumption and costly repairs.

Common warning signs include a drop in kilometres per tank, black, white or blue exhaust smoke from the exhaust, loss of power, rough idling, hesitation when accelerating and a check engine light.

Diagnosis before replacement

“Most people assume their vehicle just uses more fuel as it gets older, and they accept it,” says Nicole Kofahl, Managing Director at JEG Diesel. “But very often there’s a specific, fixable cause. Injectors are a classic example. When they wear or get dirty, the engine can still run reasonably well while quietly burning more diesel than it should. At current prices, that adds up to a lot of money every month.”

JEG Diesel’s advice is to keep an eye on consumption. If your kilometres per tank have dropped and your driving hasn’t changed, have the fuel system tested. Using specialised Bosch and Denso diesel injection testing equipment test benches, they can check each injector against manufacturer specifications. 

Then, depending on the injector type, its condition and the test results, they can clean, refurbish and calibrate the injectors. This can often be done at a fraction of the cost of buying new. Restoring the fuel system can help bring back efficiency and can potentially protect the engine from more serious damage further down the line.

Simple steps to keep fuel costs down

Alongside regular servicing and fuel system checks, JEG Diesel recommends that drivers track their fuel consumption at every fill-up so that any change is spotted early. Fuel and air filters should be replaced on schedule, and tyres kept at the correct pressure. 

Drivers can also save fuel by avoiding unnecessary idling, removing excess weight from the load bin, and buying diesel only from reputable, branded service stations. The same principles apply to petrol vehicles, and JEG Diesel also offers ultrasonic cleaning and testing of petrol injectors.

Book a fuel system check

With diesel prices at record levels and further increases on the horizon, a vehicle that uses more fuel than it should is an expensive problem that is easy to overlook. JEG Diesel encourages motorists, farmers and fleet operators who have noticed a rise in consumption to have their fuel system assessed. Contact JEG Diesel on 021 511 9197, via WhatsApp on 071 303 8692, or request a quote at www.jegdiesel.co.za. Customers outside Cape Town can courier injectors and pumps to the workshop, and collection and delivery can be arranged.

About JEG Diesel

Established in 1971, JEG Diesel is an independent diesel fuel injection and turbocharger specialist based in Paarden Eiland, Cape Town. Serving customers across the Western Cape, the company also accommodates nationwide courier arrangements for diesel injectors and pumps.

Operating from its specialist workshop, JEG Diesel uses advanced Bosch and Denso diesel injection testing equipment to assess, test, repair and recondition diesel fuel system components. The company also provides vehicle diagnostics, turbocharger services and general vehicle servicing.

JEG Diesel diagnoses, cleans, refurbishes and calibrates common rail and mechanical injectors, rebuilds common rail, rotary and inline diesel pumps, reconditions turbochargers, cleans and tests petrol injectors, and services both diesel and petrol vehicles, covering major brands including Toyota, Ford, Nissan, Isuzu, Volkswagen, Mercedes-Benz, Land Rover, Mitsubishi, Jeep and Hyundai.