Modern diesel engines are still capable of huge mileage, but they aren't quite as simple or forgiving as the older diesels that built their reputation for being almost indestructible.

In this video we look at what actually changed.

Modern common rail fuel systems, DPF regeneration, EGR systems, emissions equipment and much higher fuel pressures have made diesel engines cleaner, quieter and more powerful, but also more sensitive to the way they're driven and maintained.

Short trips, interrupted DPF regenerations, neglected fuel filters and even using an oil that doesn't meet the correct specification can eventually turn into expensive problems.

This isn't about saying modern diesels are unreliable. Plenty of them comfortably reach very high mileage.

The point is that a modern diesel needs to be treated differently from an old mechanical diesel. We explain what DPF regeneration is doing in the background, why clean fuel matters so much to high pressure pumps and injectors, what owners should know about low ash engine oil, and why simply deleting a DPF or EGR system doesn't always fix the original problem.

If you own a diesel car, SUV, pickup or van, let us know what you drive and how many miles or kilometres it's covered. I'd especially like to hear from owners with 200,000, 300,000 or even 500,000 mile diesels and what repairs you've actually had to do along the way.

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