First of all, don't do it if you rely on the vehicle.. I think you can just disconnect the fuel injectors on one bank of cylinders (one group of 4 adjacent) This is done for thermal reasons I believe. Cadillac has been doing this for a long time. The issue is that you don't save 50% of fuel because the pistons are always going up and down, and that's a lot of friction. If I had a big old V8 to try this on, I would. I'd be very interested to see what your results are. I think I would put 4 DPDT relays one on each of the 4 injectors (normally ON) Start the engine, and see what happens as I sequentially turn off the 4 injectors. The ECU will probably go crazy, don't you think? - ML On Mon, Dec 29, 2008 at 7:26 PM, Michael Algernon wrote: > What is involved in making a internal combustion ( gasoline or > diesel ) engine with '"n" cylinders operate on "n" divided by two > cylinders ? Does one just turn off the injectors ? Are there other > requirements ? Does one vary the cylinder usage to reduce noise and > wear ? Can a DIY meddler attempt such a project on a 1997 8 cylinder > gasoline fueled SUV ? What are the fuel saving ramifications ? > Ideally I would like to drive around on "4" cylinders and switch to > "8" cylinders to pull a trailer. > MA > > WFT Electronics > Denver, CO 720 222 1309 > " dent the UNIVERSE " > > All ideas, text, drawings and audio , that are originated by WFT > Electronics ( and it's principals ), that are included with this > signature text are to be deemed to be released to the public domain as > of the date of this communication . > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist