Fiat 500 1.3 Diesel Is It Right for You?

The Multijet Diesel: Economy Champion with Caveats

The 1.3 Multijet diesel is not the most popular 500 engine (diesel represented only 5-10% of UK sales), but it remains the most economical option available. Offered in both 75 bhp and 95 bhp variants, the Multijet is a turbocharged four-cylinder diesel with 200 Nm of torque — more than double the torque output of the 1.2 petrol. The diesel is significantly quicker (0-62 in 10.5 seconds vs 12.9 for the 1.2) and delivers exceptional real-world fuel economy (60-70 mpg on highway driving).

However, the diesel 500 comes with a critical caveat: the diesel particulate filter (DPF). The DPF requires active regeneration during highway driving to clear accumulated soot. Owners who restrict their driving to short urban journeys (under 10 miles per drive, consistently below 35 mph) risk DPF clogging, which can result in expensive repairs (£800-1,200 for professional DPF cleaning or replacement). This makes the diesel 500 unsuitable for pure city drivers.

Engine Design & Performance

The 1.3 Multijet is a four-cylinder turbocharged diesel with direct common-rail injection. Both the 75 bhp and 95 bhp versions produce identical torque (200 Nm), making acceleration feel brisk compared to petrol alternatives. The 75 bhp version is adequate for general driving; the 95 bhp version delivers noticeably improved performance on motorways and merging. The diesel characteristic — high torque at low rpm — means the engine feels strongest when pulling away from traffic and on hills, where small petrol engines would struggle.

Timing belt service is required every 72,000 miles. Diesel engines are sensitive to timing belt condition, and replacement should not be delayed. Budget £600-900 for professional timing belt replacement at an independent garage.

Real-World Fuel Economy

The official WLTP figure of 60-72 mpg is realistic for drivers who regularly complete longer journeys (50+ miles) at highway speeds. Real-world owners report consistent 60-70 mpg on mixed driving, with motorway runs achieving 65-70 mpg if driven at steady speeds (60-70 mph). City-only driving drops economy significantly — urban use typically returns 45-55 mpg, eliminating the diesel's economy advantage.

The diesel's advantage over the 1.2 petrol becomes clear on high-mileage driving. A driver doing 15,000 miles per year on highway and dual carriageway will save £300-500 annually in fuel compared to a 1.2 petrol. However, a pure urban driver will save nothing — and risk expensive DPF problems.

The DPF Problem Explained

The diesel particulate filter captures soot and other particulate matter to meet EU emissions standards. DPF regeneration occurs passively during normal driving when the engine reaches sufficient temperature and exhaust flow to burn off accumulated soot. This happens naturally on motorway driving or sustained highway cruising above 35 mph.

Problems arise when owners restrict driving to short urban journeys. In this scenario, the engine never reaches sufficient temperature for passive DPF regeneration. Soot accumulates, the DPF becomes clogged, and the car's ECU activates forced regeneration (you'll notice rough running and high fuel consumption as the engine burns extra fuel to regenerate the DPF). Eventually, the DPF may become so clogged that the car enters limp mode with reduced power.

Professional DPF cleaning costs £400-600. Full DPF replacement (if irreparably damaged) costs £1,000-1,500. This is a real risk for urban-only 500 diesel drivers — one reason diesel cars remain unpopular in UK cities.

Service & Reliability

The Multijet engine itself is robust and proven across millions of Fiat, Lancia, and Alfa Romeo vehicles. However, regular servicing is more critical for diesel engines than petrol. Oil change intervals are typically 20,000 miles or annually. Diesel-specific oil (5W-30 or 5W-40) must be used — petrol oil is unsuitable. Cost is £120-180 at independent garages or £200-280 at Fiat dealers.

Fuel filter replacement is essential every 30,000 miles on diesel cars. Modern common-rail diesels are sensitive to water contamination in fuel — if a car sits unused for several months, condensation can form in the fuel tank. Running the car regularly prevents this.

Who Should Buy the 1.3 Diesel?

The Multijet diesel is ideal for long-distance commuters or drivers completing 20,000+ miles annually on mixed highway and rural roads. For business users or delivery drivers, the exceptional torque and fuel economy make the diesel a financially sound choice — even accounting for higher insurance and maintenance costs.

The diesel is NOT suitable for pure urban drivers, school-run specialists, or anyone restricted to short journeys under 10 miles. For these drivers, the 1.2 petrol or 1.0 mild hybrid is objectively better. The DPF risk outweighs any fuel economy savings if you don't do regular highway driving.