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Discussion Starter · #1 ·
Hello,


Please take a look at the following video:

video

The car was driven at a steady 50KPH most of the time. Both Bank 2 sensors are showing lean measurement.

1. Are Bank 1 sensors cycling interval fast enough? Is the O2 sensor becoming lazy?
2. What's your opinion on the lean mixture reported most of the time by bank 2 sensors?


I know that only pre-cat sensors are used by the ECU for mixture information. Any opinion/advice will be welcome.

Occasionally an error is thrown that the heater of bank 2 sensor 1's heating is not working. This is the same sensor which rarely changes its value in the video. I will buy two Bosh pre-cat lambda sensors with part numbers 11781742050 in a couple of weeks and I will report back the difference.

The fuel consumption seems high although I don't have a reference for comparison._a_
 

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Discussion Starter · #2 ·
FYI I changed the pre-cat O2 sensors long time ago and I decided to let you know what happened.

The new sensors react much faster compared to the old ones. The engine used to throw a lambda control error sometimes and now it doesn't. However the fuel consumption didn't improve at all. Well, I got used to it.
 

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If you live and/or drive in the city, the Fuel Economy will never be good. In order for Fuel Economy to be good you must drive on the highway the majority of the time. 50-70 MPH steady state.

Reset the Average MPH/kph and note this value for each tank of fuel. If the Average Speed per tankful is not at least 2/3 what typical highway speeds are, Fuel Economy will appear to be poor. Even if the Average Speed is 2/3 of what a typical highway speed may be, the Fuel Economy will still be reduced from the maximum achievable value.

While the engine idles at stop lights, stop signs and in traffic, the car will get EXACTLY 0 MPG-100km/l. Average this into an moving Average Speed and it will still kill the Fuel Economy. More often than not the Fuel Economy exceptions are wrong for how the car is actually driven.

http://forum.e46fanatics.com/showthread.php?t=1077106

http://forum.e46fanatics.com/showthread.php?t=1127676

http://forum.e46fanatics.com/showthread.php?t=1198321
 

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Discussion Starter · #4 · (Edited)
Thanks. Yeah. I drive in a city most of the time, although without much traffic. I get around 14 MPG or 17 litres per 100. The engine is in perfect condition, the car is automatic and a convertible (heavier). I will take a look, but the average speed is probably about 20 km / h.

I decided not to be so OCD about the fuel consumption. It is a very pleasant car to drive, that's what counts. :)
 

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Thanks. Yeah. I drive in a city most of the time, although without much traffic. I get around 14 MPG or 17 litres per 100. The engine is in perfect condition, the car is automatic and a convertible (heavier). I will take a look, but the average speed is probably about 20 km / h.
Traffic has little bearing on Average MPH/kmh. I grow old at traffic lights in my area, but I also have to sit in stop and go traffic as well.

14 MPG is absolutely NORMAL for a City driving situation especially when you have an Average Speed of 20-25 km/h. The car is sitting still more than it is moving at speed.

Forget about everyone that will chime in here and claim 30-35 MPG on their 15 year old E46 with 250k miles on the odometer. It really does not happen and only under ideal driving condition do these cars get over 25 MPH and doubtful many get 30+ MPG, but some configurations under some ideal driving conditions may get close. 50-65 MPH continuous, steady driving on reasonably level surfaces is where most vehicles get ideal Fuel Economy. The moment you are speeding up and slowing down and have to stop, the Fuel Economy just starts to drop. At 70 MPH and over, wind resistance and higher engine RPM's will cause the Fuel Economy to start to drop off again.

Even on the highway, I drive my cars hard, I have places I need to be. I make 1100 mile trips here in the US and often have Moving Average Speeds for my 1100 mile trip of close to 75 MPH. This is close to a Cannon Ball Run or Gumball Rally type of trip! And BTW this type of Highway driving is not good for Fuel Economy either.
 

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I suppose I shouldn't be surprised that, on our last trip to Montana,
I couldn't get the 330 to do 30mpg-

average speed=79....

Moving air DOES take energy!
heh,
t
 
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