Merc E Class 2.2 cdi auto saloon 2002, 110k miles. Any experience/benefits of using Oil Flush, Oil Additive and Diesel Additive - for obtaining all the suggested benefits. I am particularly interested in obtaining a good economy - having done everything else (tyre pressures, remove junk from car, no severe accel/braking, planning ahead, no high speed etc etc). Have heard a lot about Forte Additives from various professionals who swear by its benefits. What is YOUR experience of these products? Would you recommend a Oil Flush ??? I am also told various additives are gimmicks - but Forte products are genuinely very effective and represent v good value for money.... Any comments ??