Isn't the orice differential between 87 and 91 about 10-13% now? Is that worth fussing about? You can make that much difference in driving style. I pump 91 into the ML and don't think twice about it. Tha havning been said, I'm monitoring fuel mileage using ethonol contamenated fuel and clean fuel - seems to be about a 7% increase for pure gas, but I only have two tanks of each on record so far - too small a sample to draw a conclusion from yet. On Fri, Jul 22, 2011 at 11:38 AM, Donald Snook <dsn...@mtsqh.com> wrote:
> Craig wrote: "Both the E420 and E320 require premium, so that's a wash. But > thank you > for thinking of it." > > Not that I want to start a premium fuel thread (or maybe I do! :) ), but do > they really require premium? My indy was very upset with me when I told him > I always put Premium in the E320. He said the car doesn't need it. I told > him the owner's manual says it needs it, Mercedes says it needs it and the > fuel filler door says premium only. He says that the car is equipped with a > knock sensor and is you use 87, the computer will compensate for the lower > grade and it will run just fine. I know he is correct that the car has a > knock sensor and probably the computer will compensate, but is that really > desireable? I mean, if it was designed to run on premium do we really want > to have the computer compensating and lowering performance? Is it really > "designed" to run on premium? In other words, is there some detrimental > effect on the car running 87 all the time and having the performance > affected? (by the way, I think I just used both effect and affect correctly > in a sentence - but not sure). > > My BMW manual says that 91 should be used. But, it specifically says that > the computer will compensate for lower octane, but not to go below 87. > > Donald H. Snook -- OK Don 2001 ML320 1992 300D 2.5T 1990 300D 2.5T 1997 Plymouth Grand Voyager _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
