Extended service intervals are costing franchised dealers a fifth of their traditional service and repair business, new research claims.

But non-franchised service workshops are seeing a small growth in business, as the increased level of technology in today’s car parc continues to drive out DIY servicing.

The number of cars less than four years old whose owners admit they “have not yet been serviced” has grown from just 14% of the parc in 1994 to 35% 10 years on, according to the latest Castrol Business Services Trend Tracker report, published by automotive market analyst Trend Tracker.

It puts most of this increase, which equates to a 20% decline in service visits, down to extended service intervals.

“This is a significant and serious trend that will have most impact on franchised dealers that, on average, currently retain the service business of 56% of under four-year-old cars bearing their franchise badge,” says Robert Macnab, Trend Tracker director.

He believes the statistics could even understate the true loss in business terms, because a companion study has indicated a 32% loss of labour hours because each service now takes less time, on average. And improved product reliability quality is having further impact as parts replacement business is in decline.

Nevertheless, Trend Tracker reports that franchised retailers’ service retention of older vehicles is beginning to rise, particularly with cars in the four- to six-year parc. They currently have a 36% share of the “out of warranty” sector, almost matching the independent sector’s 37% share.