A number of posts on this board indicated that people have experienced significant mileage gains at the 6000 mi (9700km) mark due to the engine becoming fully broken in. Some have even suggested that this change came on quite suddenly.
Does the ECU hold the engine in a break-in period setting, relative to the mileage, where the fuel mixture is richer than it would be normally? This would seem to make sense from a number of angles, but I don't know anyway of confirming it. Does anyone have any ideas or feedback?
My 05 NISMO CC is at 9450km now, so I hope to experience a trickle of fuel economy soon.
The ECU making it richer until 6,000? No way. I've seen those posts too and they are merely unsubstantiated speculation. Things ought "loosen up" as the miles go by, but that's about it.
I dunno man.....both my 05 frontier and my dads 05 Xterra did the exact same thing....as soon as they hit 6000 mileage went up 2-3MPG...
Now Granted, I havent talked to Any Nissan engineers lately,(and I used to be able to every DAY too!), so I dont know if it actually DOES do it. but it does seem too...
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2005 Nissan Frontier
Aztec Red, KC, 2x4, 6-Speed, Roll Up windows, ALLOYS! aFe Stage II Intake, Helper Spring Mod.
15.759s @ 87.36MPH
2005 Nissan Xterra
Canteen Green, SE, 4x4, Auto.
some ecm's are programed to not allow full power potential until some sort of mileage, but i can honestly say i haven't seen it and i just crossed the 6k mark with my 05
mileage going down could be a combination of things at that mileage - tire pressure fuel system might need some cleaner, fuel filter change is approaching, older oil (if it wasnt chanegd recently) could be a few things
Well I'm on 5900 miles this tank so I'll be sure to check. Overall MPG has been on the up and up since I bought it though. Started @ 17mpg, now its around 19mpg. I do about 50 miles a day, 30 on highway (in traffic). I have a 4x4 SE CC with 6 spd. I'll check to see if this tank gets better mileage than the last.
some ecm's are programed to not allow full power potential until some sort of mileage, but i can honestly say i haven't seen it and i just crossed the 6k mark with my 05
I guess one way to test the theory of ECU conditioning is to pull the battery and allow the ECU to reset to the factory default values (I do not think a code reader will reset the operating parameters, just the MIL codes). Checking the gas mileage after that could help prove or disprove the theories.
I guess one way to test the theory of ECU conditioning is to pull the battery and allow the ECU to reset to the factory default values (I do not think a code reader will reset the operating parameters, just the MIL codes). Checking the gas mileage after that could help prove or disprove the theories.
I'm not sure how that would prove the theory, disconnecting the battery won't reset the odometer, and the ECU is probably tied to that if it actually tracks mileage.
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I'm not sure how that would prove the theory, disconnecting the battery won't reset the odometer, and the ECU is probably tied to that if it actually tracks mileage.
Depends if the ECU is reading the odometer (I bet it does not). If the ECU is just adjusting to engine operating parameters then the reset should reduce gas mileage.
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