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Mark
02-13-2000, 05:54 PM
I recently picked up an '83 745i that I have come to adore in the last few weeks. The turbo response is fantastic and the ride at 110 is smooth as silk.<br>There is one big problem!!! This car is only getting 10mpg!!! I have owned numerous M30 engines that averaged anywhere from 17 to 25mpg but something definitely is wrong here. When driving the car to see how good of mileage I could get without getting on boost very often, the best I could do was 12mpg!!<br>I know it would get a little less than most M30's because of the 3spd auto, but I was expecting at least 15mpg.<br>Can someone help me solve this problem because I can't afford to drive this car getting this kind of mileage. It recently had a new O2 sensor installed with airflow meter adjustment. Car runs absolutely fantastic, idles a little rough. (all M30's??) Noticed that after sitting at idle sometimes, it can load up and blow a little black smoke, not much.<p>Any help would be greatly appreciated.<p>The local gas station loves my new car!!!!!!<p>TIA<p>Mark

Bob
02-14-2000, 01:53 PM
This is about normal for the 745i in city driving.<p>They reduced the compression ratio for the turbo, then richened the mixture to help cool things off.<p>The result is 12-15mph.<p>Bob

JEFF
02-15-2000, 12:23 AM
Mark,<p> Sorry to tell you, but my car runs lean and it only get 14 MPG on a really good day. Sound like your car is right in "the range." I will back to you about the HKS controller. My boss is out of town until tommorrow.<p>-Jeff<p><i>: I recently picked up an '83 745i that I have come to adore in the last few weeks. The turbo response is fantastic and the ride at 110 is smooth as silk.<br>: There is one big problem!!! This car is only getting 10mpg!!! I have owned numerous M30 engines that averaged anywhere from 17 to 25mpg but something definitely is wrong here. When driving the car to see how good of mileage I could get without getting on boost very often, the best I could do was 12mpg!!<br>: I know it would get a little less than most M30's because of the 3spd auto, but I was expecting at least 15mpg.<br>: Can someone help me solve this problem because I can't afford to drive this car getting this kind of mileage. It recently had a new O2 sensor installed with airflow meter adjustment. Car runs absolutely fantastic, idles a little rough. (all M30's??) Noticed that after sitting at idle sometimes, it can load up and blow a little black smoke, not much.<p>: Any help would be greatly appreciated.<p>: The local gas station loves my new car!!!!!!<p>: TIA<p>: Mark<p></i>

mark
02-15-2000, 12:11 PM
Jeff,<p>Boy, I sure thought I could get at least 15mpg out of this thing!! This one might be running slightly rich as to not knock when on boost but it sure is fun to drive! I guess thats the price you pay for BMW fun.<p>Let me know when you hear back from your boss about the HKS unit and any other ideas on how to increase boost on this car.<p>Thanx again,<p>Mark<p>:


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