PACCAR DAF PX5 vs PX7: Which Engine Powers Your Fleet Best?

Deciding between the PACCAR/DAF PX5 and PX7 for your DAF truck? You’re not alone – many fleet operators are in the same position, weighing this decision carefully.

Both engines were first introduced as part of the Euro 6 DAF LF range and have earned a reputation for their reliability and fuel efficiency on UK roads. While earlier models shared technology with Cummins, the latest versions have been completely reworked by DAF. The PX-5 (4.5L) originally offered power options of 170, 190, and 210hp, while the PX-7 (6.7L), which also fits in the DAF CF model, was built for those needing more torque and durability, with power ranging from 230hp to 310hp.

By 2022, DAF released a new generation of PX engines, featuring lightweight yet durable Compacted Graphite Iron (CGI) blocks, low-friction pistons, more efficient compressors, and enhanced waste-gate turbos. Along with the 8-speed fully automatic PowerLine transmission, these updates have delivered notable efficiency gains.

Both engines are designed to meet the demands of modern distribution fleets, offering different strengths. But how do you decide which one’s best for your operations?

If your routes are urban-based with frequent stops, and fuel economy is a top priority, the PX-5 might be the way to go. However, if your fleet handles heavier loads or long-haul deliveries, the PX-7’s extra power and torque could make all the difference, helping your trucks stay reliable under pressure.

In this guide, we’re breaking down the key differences between the two engines – looking at performance, efficiency and cost-effectiveness – to help you make the right choice to keep your fleet running safely and smoothly.

Key Differences: PACCAR PX5 vs PX7

Choosing between the PACCAR PX-5 and PX-7 really comes down to power, efficiency, and the type of operations you run. While both engines are designed to boost fuel savings and lower emissions, they’re definitely built with different purposes in mind.

Here’s how they compare:

Both engines benefit from DAF’s latest redesign, including:

• Lightweight Compacted Graphite Iron (CGI) blocks for strength without the extra weight.
• Low-friction pistons and new wastegate turbochargers to improve combustion and overall efficiency.
• Optimised fuel injection technology to enhance fuel economy and reduce emissions.

If you’re focused on inner-city or regional routes with frequent stops, the PX-5 is more likely to offer the fuel savings you’re looking for. If you or your fleet are  regularly handling heavier loads over long distances, the PX-7 is probably the best option – provides the extra power and torque to keep things running smoothly.

Engine Performance: Power, Efficiency, and Real-World Application

The PACCAR PX-5 and PX-7 may share the same DNA but, when it comes to on-road performance, each engine has been designed with a specific type of fleet in mind.

Here’s how they differ:

PACCAR PX5: Agile and Efficient

Designed more for urban distribution and regional deliveries, the 4.5L PX-5 balances fuel efficiency with responsive performance, making it ideal for stop-start driving and tight delivery schedules.

• Power Output: 170 – 210hp
• Torque: 700 – 800Nm
• Peak Torque Range: 1,100 – 1,700 rpm
• Ideal for: Light-duty applications, frequent stopping, and fuel-conscious fleets

The PX-5 performs well in urban environments, where its lighter weight and rapid throttle response allow for quicker acceleration and smoother stop-start operations. The low-end torque delivery helps maintain performance without over-revving, reducing fuel consumption while keeping operating costs low.

If you’re looking for maximised efficiency in short-haul or local distribution routes, the DAF PX-5 will be a cost-effective and reliable option.

PACCAR PX7: Built for Heavy Loads and Longer Distances

For operators handling regional and long-haul distribution, the 6.7L PX-7, which fits in both DAF LF and CF, provides the extra horsepower and torque needed to haul heavier loads with ease.

• Power Output: 230 – 310hp
• Torque: 900 – 1,200Nm
• Peak Torque Range: 900 – 1,800 rpm
• Ideal for: Heavier payloads, regional and national distribution, fuel efficiency over long distances

The PX-7’s high torque output at lower engine speeds means less strain on the engine during acceleration and sustained cruising, reducing fuel burn on longer routes. The stronger engine block and improved cooling system ensure durability under higher loads and tougher conditions.

For fleets that operate across motorways, regional hubs, or carry larger payloads, the PX-7 provides a significant performance advantage over the PX-5.

Which One Performs Best for Your Fleet?

If your fleet focuses on urban or regional deliveries, where fuel savings and agility matter most, the PX-5 is the better fit.

If your trucks are carrying heavier loads over longer distances, and you need more torque for efficiency and durability, the PX-7 is the smarter investment.

Both engines are built with industry-leading fuel efficiency, reliability, and compliance with Euro 6 standards, making them solid choices depending on your fleet’s needs.

Fuel Efficiency and Cost Savings: Which Engine Saves You More?

Fuel efficiency is a top concern for fleet operators, especially with rising fuel prices and stricter environmental regulations. We understand that every litre counts, and both the PACCAR PX-5 and PX-7 have been redesigned to deliver up to 7% savings in fuel. 

But which engine offers the best return? That depends on your fleet’s operations and routes.

PACCAR PX5: Maximum Efficiency for Short-Haul & Urban Fleets

The PX-5 is built for the demands of stop-start driving, making it perfect for fleets operating in cities, regional hubs, and for last-mile distribution. Its lightweight 4.5L design and lower displacement work together to reduce fuel consumption, and several engineering upgrades push efficiency even further:

✅ Lower engine speed peak torque – Less revving means less fuel used.

✅ Low-friction pistons – Reduces energy loss within the engine.

✅ Optimised turbocharging – Improves air intake for better combustion.

✅ Euro 6 emissions compliance – Lower CO₂ and NOx emissions.

Best for: Operators looking to cut fuel costs on shorter, stop-start routes without compromising on quick response times or reliability.

PACCAR PX7: Efficient Power for Longer Hauls

While the PX-7 delivers more power, it also benefits from down-speeding technology, allowing it to generate higher torque at lower RPMs – reducing fuel burn over longer distances and heavier payloads.

Key features that improve its efficiency:

✅ Higher torque at lower RPMs – Reduces fuel usage on motorway and regional routes.

✅ Improved combustion efficiency – Delivers more power without increasing fuel consumption.

✅ Longer service intervals – Less maintenance downtime means lower running costs.

Best for: Fleets covering regional and long-haul routes, where efficiency at sustained speeds and higher loads is crucial.

Maintenance & Reliability: Keeping Your Fleet Moving

Minimising downtime and maintenance costs is just as crucial (if not more so!) as fuel efficiency when it comes to keeping your DAF truck or fleet running smoothly. Both the PACCAR PX-5 and PX-7 are built for durability with long service intervals, but their maintenance needs vary depending on how they’re used.

PACCAR PX-5: Low Maintenance for Urban Fleets

The PX-5’s compact 4.5L design means fewer moving parts compared to larger engines, reducing wear and tear – especially for fleets that operate in urban and regional distribution. Its maintenance benefits include:

• Lightweight CGI engine block – Stronger than traditional iron but reduces overall engine stress.
• Common rail fuel injection system – Delivers precise fuel metering, reducing injector wear.
• Simplified cooling system – Designed for lower thermal stress, extending engine lifespan.
• Euro 6 emissions technology – Integrated Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) for cleaner operation.

PACCAR PX-7: Built for Heavy-Duty Reliability

Although the PX-7 demands a bit more attention in terms of maintenance compared to the PX-5, it more than makes up for it with longer service intervals and fewer major overhauls. Here’s what makes it so reliable over the long haul:

• Stronger crankshaft and camshaft – Designed to handle sustained power output without excessive wear.
• Reinforced pistons and cylinder head – Built for durability under high-load conditions.
• Extended oil change intervals – Reduced need for frequent servicing.
• Efficient cooling system – Helps prevent overheating during long-haul journeys.

PX5 or PX7: Which One is Right for Your Fleet?

Deciding between the PACCAR PX-5 and PX-7 comes down to how your fleet operates and what demands you place on your trucks daily.

If you’re used to handling urban and regional deliveries, the PX-5 is likely to be the more practical choice. Its lighter weight and lower displacement make it far more fuel-efficient, especially if you’re regularly operating in stop-start environments like city centres and regional hubs. Because it requires less maintenance and consumes less fuel, it’s a great choice if you’re looking to reduce running costs without compromising on performance.

Meanwhile, the PX-7 is built for power and endurance. If you’re regularly moving heavier loads across longer distances, this engine’s higher torque and horsepower offers better performance. It’s well-suited for regional and long-haul routes, where fuel economy at sustained speeds and overall durability are critical. While it might be more costly in the first instance, its extended service intervals and reinforced components make it a cost-effective long-term choice. Plus, it’ll also suit your DAF CF truck (along with the LF) if you have multiple models in your fleet.

Regardless of which engine best suits your fleet, sourcing high-quality parts is key to keeping your trucks performing at their best.

Get High-Quality PX-5 & PX-7 Complete Engines and Components from PT Parts

Keeping your fleet running efficiently starts with quality parts you can rely on. For almost 10 years, Premier Truck Parts has provided a vast range of high-quality new, used and reconditioned truck parts for all models of DAF trucks, supporting hauliers, garages, importers, insurance companies and damage repair companies both in and out of the UK.

Why choose PT Parts?

• OEM-quality parts at a cost-effective price.
• Warranty-backed reliability to ensure confidence in every purchase.
• Fast delivery across the UK, Europe, and beyond, minimising downtime for your fleet.
• Knowledgeable team ready to help you find exactly what you need.

If you’re unsure which parts best suit your fleet, our experienced team is here to help. Whether you need a complete replacement PX-5 engine for a city-based truck or PX-7 engine components to keep your long-haul fleet running smoothly, we’ve got you covered.

Get in touch with PT Parts today for expert advice. Call us now or visit our online store to browse our latest stock.