My mother rarely covers more than 4000 miles a year and the MOT centre
> failed the car on the above.
>
> She doesn't wish to do more miles, so how can she avoid a failure again next
> time.
>
> Are there additives she can use ??
An additive may help, but the best solution is for her to let you borrow the car once a month or so, and just before the MOT and take it for an italian tune up- hard acceloration in each gear for several miles, plenty of revs and watch the carbon blow out the back, when it has cleared- have the mot smoke test. Does the engine the world of good too. Obviously she should be having 6month oil changes and 12month service what with her small mileage.
Tim..