I was trying to comprehend what mistake I had done by mentioning Power to Weight ratio here. The whole idea of mentioning it is to make a case why performance issues are not as pronounced in Swift/Dzire or Vista/Manza as they are in Punto and Linea. You are mentioning the same point again. The definition of power to weight ratio and by logic where I have used looks pretty apt to me. I have gone through my post again couple of times and cannot see anything to be interpreted loosely. I meant what I said and stand by my views which make sense from all the real world aspects if you care to see closely. Please dont take it the wrong way, but some parts of the explaination still don't make me understand the relevance to core issues at discussion here; atleast to my point of view or the fallacy or falsity thereof if any in the first place. I am not willing to make generic comparison between the engines or it's built qualities with regards engine block and head etc. since it served no point given that most are manufactured at Ranjangaon, Pune. The fuel injection systems used however, the ECU that controls it, the performance mapping there is to the cars and the power to weight ratio, all are or could be tipping to make a car like Swift DDiS more zippier to perform (arguably at that again). Honestly, the figures about gear ratio are good for this discussion, but again you see if you read the first post you will find the discussion is about performance issues without ECU errors. Gear ratios as you mentioned will have effect in everyday drives. Agreed. But Bhai is talking of performance drop without ECU. That performance which was adequate otherwise, given the gear ratio pro and cons. Palio MJD, for example can beat the Swift and provides some exhilarating performance as per people I have had feedback from. Did it have similar or different gearing ratios and where it lacks against Punto is another topic which might give us better angles to look at this problem. Again to summarize, Bad fuel, particles in fuel supply lines, Injector clogging, bad engine oil, Clutch problem, rusted wheel bearings, Fuel pumps, EGR (an eyesore for many as will be evident from queries on EGR and aptly mentioned by Gurjinder) and gear ratios (mentioned by yourself). A few or many of the above in conjunction with each other lead to issues that cannot always be picked up by the ECU. - - - Merged Post - - - Bhai, why not see MJD vs DDiS or Quadrajet? Your friends are right I say if you compare with other manufacturers also. Your point is why Fiat cannot see the issues that effect engine performance. I agree with it. And that is why you see I support your friends' view who think you like to compare MJD with DDiS and Quadrajet. Let them think about it and you ask them what makes their cars if they own Vista or Swift DDiS perform without deterioration. Bhai with regards EGR I have cited somewhere from an article when EGR get clogged as per expert opinion, not mine of course. While bad quality fuel is responsible. There maybe other reasons also which you will need to rule out. Right now what is the status of this problem of yours. What is the opinion of FASS about the same. IIRC, you got whole lot of things changed under extended warranty recently right. What according to you was the culprit and does it perform better now. Do post your finding for us to be careful about in the future.