I am curious here: where would all the extra energy be going? is the backpressure causing incomplete burning and fuel is being lost without all the energy being extracted from it, or is the engine becoming much less efficient and all the extra energy is going into heat somewhere? If it is the latter, it seems likely that something would have overheated. I suppose that maybe the cooling system could handle it but it certainly would be a big increase in waste heat. On Fri, Mar 30, 2012 at 11:17 AM, Bob Blick wrote: > On Fri, Mar 30, 2012, at 11:30 AM, Tamas Rudnai wrote: >> However, after removing the >> filter I have noticed that the fuel consumption is much better, it is 61 >> mpg (Imperial, or 51 us mpg, or 4.5 l/100km). Previously (with the DPF >> still in) this figure was way worse, maybe I could achieve 40 mpg (33 us >> mpg), which is not entirely surprising as the filter is basically a >> blockage in the exhausting pipe system -- causing the engine work harder >> to >> push the exhausting gas through that. > > It's broken. When it's functioning properly it does not block the > exhaust. Most exhaust systems are well-designed and you should not have > an increase in fuel economy by removing a component. Do you have a > warranty? Emissions-related parts have a 70,000 (or something equally > large) mile warranty here. The on-board diagnostics should have alerted > you with a "check engine" light a long time ago. > > Bob > > -- > http://www.fastmail.fm - Does exactly what it says on the tin > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .