MAF test L/h - Page 2 - The Unofficial BMW M5 Messageboard (m5board.com)

///Manuel · 10th July 2008, 21:07

Alan, excellent point, according to my OBC I am getting 30mpg after some serious spirited driving (trying to get a feel for how the engine is running), it should be more like 8. It's not necessarily the MAF's fault.

nebpor · 10th July 2008, 23:33

Manuel, have you tried removing the ECU for 10 minutes to reset it? Either that or there is a procedure in the manual to reset the MPG figure!

///Manuel · 11th July 2008, 18:59

I reset my OBD and that's what it gave me. I checked my fuel pressure last night and it stays right around 50, a little more when throttle is applied (52-53psi) and a little less when released (48ish).

overflowpy · 11th July 2008, 19:53

My car mark 3.4 to 3.5 l/h My car no have a O2 Sensor and I don't know is originally came with O2 sensor

davidoli · 11th July 2008, 22:18

Another sensor that can affect the fuelling is the air temp sensor that is situated in the lower half of the airbox , below the MAF .

A friend's car recently had a faulty air temp sensor whereby it was recording the air temp as minus 3 degrees all of the time and therefore over fuelled , believing the air to be denser than it actually was .

rapiddecline · 19th July 2008, 17:42

I do not rely on the sensors or the obc the only way I check this is to fill the tank to the neck -- drive to wherever--- refill to neck and calculate fuel used by distance travelled . This then I find more accurate than the obc my last trip involved 1600 miles including a few 150 mph blasts 8 ring laps and a few refills. I added they amount of fuel used and calculated with the milage to 26.6 miles to the gallon. I dont think I can complain at that.
andy