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![Anon](/assets/aa/aa-avatar.png?m=1466990309)
I have a signature class diesel Toyota Surf that is required to be serviced (including a change of oil) every 5000km under the terms of the guarantee.
Why does the oil have to changed so often? Petrol powered cars go for 10000km or more before an oil change.
Gary
From the "Ask Jack" archives - 23 April 2010
![jbiddle](themes/aaAle/images/interface/profile-pic-placeholder.47cf740a.png)
Early engine design with diesels meant more regular servicing intervals was required to keep the engines free of excessive sludge and to retain a high oil quality circulating through the engine.
Most diesel engine oils have higher detergent levels than petrol oils for this reason.
This along with Road User Charges are some of the important issues we point out to people considering Diesel over Petrol.
The amount of oil and the cost of oil filters in a diesel can also be more than in a petrol engine.
The majority of modern common rail diesels have the same service intervals as petrol's such is the progres that has been made.
Keep up the servicing, you don't want to have to pay for a diesel engine overhaul