need help diagnosing immediate 2mpg drop in fuel mileage after routine maintenance.
11-20-2008, 11:16 AM
#21
i wish i ran up on your posts in my searches about fuel treatment. so, we're both guessing the same, could it be the plugs or O2 sensors being messed up by the clearing deposits? was it a permanent drop in mpg or did it return? should i run ONE more tank of the stuff or no? i've read about someone saying it took a few tanks for the mileage to return which is BS. i would have left well enough alone.
as far as redline MT90 is concerned, yes, it's horrible for me on the first shift in the morning. one thing i started doing was lightly winding the first gear to about 4,000rpm until i reach that first corner out of my development to get the gear oil circulating completely. i've done this for two days and the first 1-2shift has been nice and buttery since. i still want to change back lol.
anyway, this is a situation where i truly believe "if it ain't broke, don't fix it!"
as far as redline MT90 is concerned, yes, it's horrible for me on the first shift in the morning. one thing i started doing was lightly winding the first gear to about 4,000rpm until i reach that first corner out of my development to get the gear oil circulating completely. i've done this for two days and the first 1-2shift has been nice and buttery since. i still want to change back lol.
anyway, this is a situation where i truly believe "if it ain't broke, don't fix it!"
11-21-2008, 09:40 AM
#23
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It's been a long time since I've learned or done any reading about motor oil but I suspect the 0W-30 oil. For most operating conditions Nissan recommends 10W-30 and in severe cold, 5W-30.
The weather is getting cooler and the oil is thicker on start up. I suspect you need a lighter weight oil.
The weather is getting cooler and the oil is thicker on start up. I suspect you need a lighter weight oil.
11-21-2008, 11:26 AM
#24
It's been a long time since I've learned or done any reading about motor oil but I suspect the 0W-30 oil. For most operating conditions Nissan recommends 10W-30 and in severe cold, 5W-30.
The weather is getting cooler and the oil is thicker on start up. I suspect you need a lighter weight oil.
The weather is getting cooler and the oil is thicker on start up. I suspect you need a lighter weight oil.
11-21-2008, 11:43 AM
#25
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yes, he is confused. "0" is the weight of the oil when its cold, which is in fact lighter than "5". "30" is the weight of the oil at operating temperatures. Driving your car without warm up will in fact lower your fuel economy. Wake up 15 minutes earlier and save yourself from poor mpg's.
11-21-2008, 11:55 AM
#26
yes, he is confused. "0" is the weight of the oil when its cold, which is in fact lighter than "5". "30" is the weight of the oil at operating temperatures. Driving your car without warm up will in fact lower your fuel economy. Wake up 15 minutes earlier and save yourself from poor mpg's.
11-21-2008, 12:52 PM
#29
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Like stated in another thread, when your engine is cold and warming up, the A/F ratio is rich. Driving your car immediately without warming up will cause a considerable increase in fuel consumption for those first few miles until the engine is in optimal running temperatures. Now if you've been doing the same routine for several years already (on your Z) and just notice the sudden drop in mpg, then I wouldn't know what to tell you.
11-22-2008, 10:00 AM
#31
random note: my ABS actuator just started acting up again. it doesn't seem to turn off even with the keys out. second time this year it happened. http://g35driver.com/forums/g35-coup...ing-crazy.html so, i'm having infiniti look over all the electronics since the car is still under coverage. i hope that doesn't open a can of worms (it probably will)! i'm also bringing in a copy of the TSB for oil consumption and having them start a test. lol what a shi**y month for this car. wish me luck...
11-28-2008, 06:31 AM
#32
so infiniti replaced the relay to my abs actuator. as far as the mileage was concerned they said it was in the lower range of the spectrum, but nothing unusual they said after checking the engine codes, etc...oh, and they still wanted me to buy an oil change even though i mentioned the TSB about the oil consumption. maybe this spring i'll do it at a different dealer.
11-28-2008, 06:55 AM
#33
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If it was a lose of 5 miles or more i'd be concerned.My first thought was the drag on the brake pads you just installed.That would cause the lower mpg.See once you break in those pads your mpg will go back up.Its just like a motor once it gets a break in and the motor isn't fighting with fricton as much the motor spins easier.
Last edited by track1z; 11-28-2008 at 06:58 AM.
11-28-2008, 09:13 AM
#34
If it was a lose of 5 miles or more i'd be concerned.My first thought was the drag on the brake pads you just installed.That would cause the lower mpg.See once you break in those pads your mpg will go back up.Its just like a motor once it gets a break in and the motor isn't fighting with fricton as much the motor spins easier.
the brakes seem normal. i didn't notice too much drag on the wheels before and after the install (i could be wrong, but doubt it). i did re-adjust the parking brake just for kicks. the problem is i changed so many things on the car that it's hard to pinpoint what causes it. the transmission shifts kind of notchy for the first or second shift when very cold so i'm thinking the gearoil could be causing a little bit of it, but 2mpg worth?i might go back to my winning formula of oem gear oils and 5W-30 pennzoil platinum in about a month or two. lol
11-28-2008, 09:17 AM
#35
don't spend 15 minutes warming up your car. that is stupid and very bad for the car and the environment.
glad to see some progress.
I personally still don't like the synthetic transmission gear oils... not as good as the OEM stuff for DD use. especially cold weather it is much thicker and terrible on your shifts.
you should hear my rear diff in cold weather now that I have those solid mounts... lol... like a supercharger until it heats up.
glad to see some progress.
I personally still don't like the synthetic transmission gear oils... not as good as the OEM stuff for DD use. especially cold weather it is much thicker and terrible on your shifts.
you should hear my rear diff in cold weather now that I have those solid mounts... lol... like a supercharger until it heats up.
11-28-2008, 10:34 AM
#39
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Some points to consider:
1) Idling your engine = Zero MPG Plain and simple. Ask anyone who knows - you can drive your car away after about 30 secs. Google it. Unless maybe you live in -40C/-40F then maybe you should plug your car in with a block heater and you still wont have to idle for more than 30 secs. Idling to heat up the car so you can have it defrosted and not **** freezing cold is hard on MPG and the environment but its up to you. Everyone has a different outlook on that issue.
2) Your MPG will be worse in the colder temps, prob about the 10% that you're seeing. Its a list of factors such as enriched fuel starts, longer high idle, colder oils and fluids to circulate, etc etc. I've never heard of someone getting better MPG in the winter.
3) it could be a possibility that you now have a fouled or leaky injector but I seriously doubt it. You could try pulling the plugs to see if there is one that is off color but if youre not experiencing a miss during idle or under load then youre prob fine. You would prob be getting a Check ENG light if you were getting that much unburned fuel in the exhaust??? Not sure?
4) Winter gas as stated above.
5) Car OFF, Park Brake OFF, Neutral. can the car be rocked back and forth on a level surface easily? It should be able to with a light push. If not you could have an issue with your new brake pads. Maybe they are binding and not retracting like they should...I had that on an 84 ZX and wore out one side at the rear in about 5000 miles. Had no idea at all that the pad was dragging...untill i started to hear metal grinding!!!!
I personally would not be too concerned with 2 MPG diff from summer to winter. I've been seeing that for years. However I live in Canada and its pretty cold up here. My Z however is in the garage hibernating till April LOL
1) Idling your engine = Zero MPG Plain and simple. Ask anyone who knows - you can drive your car away after about 30 secs. Google it. Unless maybe you live in -40C/-40F then maybe you should plug your car in with a block heater and you still wont have to idle for more than 30 secs. Idling to heat up the car so you can have it defrosted and not **** freezing cold is hard on MPG and the environment but its up to you. Everyone has a different outlook on that issue.
2) Your MPG will be worse in the colder temps, prob about the 10% that you're seeing. Its a list of factors such as enriched fuel starts, longer high idle, colder oils and fluids to circulate, etc etc. I've never heard of someone getting better MPG in the winter.
3) it could be a possibility that you now have a fouled or leaky injector but I seriously doubt it. You could try pulling the plugs to see if there is one that is off color but if youre not experiencing a miss during idle or under load then youre prob fine. You would prob be getting a Check ENG light if you were getting that much unburned fuel in the exhaust??? Not sure?
4) Winter gas as stated above.
5) Car OFF, Park Brake OFF, Neutral. can the car be rocked back and forth on a level surface easily? It should be able to with a light push. If not you could have an issue with your new brake pads. Maybe they are binding and not retracting like they should...I had that on an 84 ZX and wore out one side at the rear in about 5000 miles. Had no idea at all that the pad was dragging...untill i started to hear metal grinding!!!!
I personally would not be too concerned with 2 MPG diff from summer to winter. I've been seeing that for years. However I live in Canada and its pretty cold up here. My Z however is in the garage hibernating till April LOL
11-28-2008, 11:40 AM
#40
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Wtf i just drove 150 miles one way to get into town with my z. Going down hill going around 85mph i got 36.7 max mpg... avg was 33.5 and going back up the 150miles i avged 26(but there was a wreck that was bad, like in 1 hour we went 2 miles). But in town i only get 8mpg to 12... is that normal?