1.6tdci 09 plate. Focus. Long drive 1h30mins +. Car seems to struggle for power / acceleration . Like gasping

[DaveD90]

Noticed in motorway on Friday heading 9n holiday with family. Car started to struggle after about 1h30mins. Was 60mph and car seemed to struggle for acceleration and it felt like it was gasping for fuel or air. 

 

Anyone got thoughts on what this could be 

[andypsp]

when did you last do a full service.. oil, oil filter, fuel filter and air filter

[DaveD90]

4 months ago. This has been my first long journey. Didn't do it on way back from holiday today either.