Service D dilemma

[Abb]

The instrument cluster is indicating a service D is due on my CLS. From my understanding this equates to a B service. The last service carried out (as per schedule) was a E service some 17 months ago and since then I have only covered a mere 4245 miles
So my question is, is this service really necessary or should I have the service indicator reset?

 

[markjay]

Your car, like mine, still has the old flexible service schedule regime.

Newer cars (post 2007) have fixed 12 months service intervals.

So if you got 17 months between services due to low annual mileage... I would not strech it beyond that.

Especially keeping in mind that oil deteriorates with age, and that many additional service elements have rigid time-based replacement intervals anyway (i.e. need replacing even if the mileage covered is low) e.g. brake fluid, air and fuel filters, spark plugs, etc.

Additionally, the effect of low annual mileage on oil quality is usually relatively greater than high mileage, because typically low annual mileage will involve a large number of short urban runs, while high annual mileage will typically comprise of long motorway cruising trips which is far less taxing in the engine and oil.

In summary I would definitely get it serviced at the time/mileage indicated by ASSYST.