[Madness!]

I am really struggling with this. My air hose doesn't seem to have any air leaks, though I could try spraying a bit of water on there to find out, all hoses are tight up against their abutments, and maybe I calculated the fuel economy before incorrectly. I went with a value from the web (21.5 gallons total) and divided my odometer reading by half of that. I've since learned that you don't have to be at half a tank to measure fuel economy, you just need a sort of empty tank and to measure the distance driven and use whatever quantity you fill it up with next to do the math...

Anyway. Using the internet value I got 10 mpg. With proper measurement, I am certain that I am getting 15-ish mpg. I don't have any codes. No misfires, or really anything except this crappy gas mileage. I had a K&N air filter in there since I purchased it which I must admit I never cleaned. That will be happening soon, but I put a disposable filter in there earlier this week. I do feel the car has more power now. The VID seemed to give a better mileage and my calculations indicated better mileage. The only problem is that I'd been using the internet method for my computations up to this point so no reliable data until this point...

Any ideas? Tire pressure is good.

[SOLUTION: ]

Some background: I replaced o-rings on both bank 1 and 2 camshaft position sensors some time ago (this year); what I did NOT do was tighten down their retaining bolts ENOUGH, part of me didn't want to break anything and didn't possess a working torque wrench at the time. A post on Nissanmurano.org mentioned it requires 85 inch-lbs yes INCH-lbs, so when I get access to a proper torque wrench you can be sure I will make certain they are tight as necessary. My engine's performance in terms of gas mileage and plain ole power has been nearly halved for months, and it varied a lot.

Once I tightened them down a bit, I fired it up and was surprised to feel it back out of the garage without being forced to gun slightly, backed her out on her own accord. Gave both banks a bit more force and went for a test drive! 21.75 mpg mixture of highway and city. VID says 23.5 MPG but I'm not counting on that. It being like 60 degrees F here I noticed she warmed up visibly (quickly!) instead of remaining cold for at least five minutes like has been. Computed mileage was from set odometer and fill up.

I do love this vehicle! Need to stop monkeying with things, heh.

 

[MuranoSL2003]

Don't go by the fuel tank spec to calculate MPG...

Fill your tank until the nozzle clicks, then stop. Reset your trip odometer. Drive until you need gas again. Fill your tank until the nozzle clicks, then stop. Divide the miles traveled by the amount of gas you just added.

Be aware the type of driving highway/town/stop&go, cold weather, etc will affect MPG.

 

[Madness!]

Don't go by the fuel tank spec to calculate MPG...

Fill your tank until the nozzle clicks, then stop. Reset your trip odometer. Drive until you need gas again. Fill your tank until the nozzle clicks, then stop. Divide the miles traveled by the amount of gas you just added.

Be aware the type of driving highway/town/stop&go, cold weather, etc will affect MPG.

...

That is exactly what I just explained above. My driving has little to do with the mileage. I don't drive especially crazy. I'm looking for MECHANICAL reasons.

I just want to say this morning is not going well for me so I apologize in advance if I come off RUDE.

 

[MuranoSL2003]

Okay...

 

[mmagliaro]

Do exactly what MuranoSL2003 suggested. That is the only way I know of to accurately measure your gas mileage.
15 mpg isn't surprising at all. I have a 2006, and just driving around town and to work which means mostly short trips with a few 15 minute highway drives here and there, 15 mpg is about all I've ever gotten. The mileage spec that Nissan quotes for the Murano of 17 city/23 highway is "optimistic" as far as I'm concerned. I can get in the low 20's on a long highway drive if I really baby it, keep the speed down, and avoid any heavy accelerations. For "city" driving with lots of short 5-10 minute drives and stop-and-go traffic, 14-15 is what it does. It is not a particularly fuel efficient car. It has a powerful V6 in it and it is has a typical curb weight of around 4000 lbs.

 

[MuranoSL2003]

Do exactly what MuranoSL2003 suggested. That is the only way I know of to accurately measure your gas mileage.
15 mpg isn't surprising at all. I have a 2006, and just driving around town and to work which means mostly short trips with a few 15 minute highway drives here and there, 15 mpg is about all I've ever gotten. The mileage spec that Nissan quotes for the Murano of 17 city/23 highway is "optimistic" as far as I'm concerned. I can get in the low 20's on a long highway drive if I really baby it, keep the speed down, and avoid any heavy accelerations. For "city" driving with lots of short 5-10 minute drives and stop-and-go traffic, 14-15 is what it does. It is not a particularly fuel efficient car. It has a powerful V6 in it and it is has a typical curb weight of around 4000 lbs.

My 16 years with my '03 matched your MPG scenarios just about exactly.

Surprisingly, my '19 does seems to do noticeably better. Especially highway MPG, which is close to 30 MPG. My trip computer displayed 33.5 during a trip, but I find the trip computer to be about 10-15% too high.

I don't think I recall my '03's trip computer displaying anything more the the mid-high 20s. I think my '03's trip computer was displaying about 10% too high.

 

[Pilgrim]

That is exactly what I just explained above. My driving has little to do with the mileage.

That simply is not true. Driving and the conditions under which you drive (traffic, speed, weather, wind, hills) is one of the biggest factors in gas mileage, if not THE SINGLE biggest factor in gas mileage.

Even if you're having a bad day, let's recognize reality. Regardless of mechanical issues, your driving and the driving conditions are a major factor, and one which is often hard to estimate consistently.

That said, a dirty air filter will cause a reduction in mileage. Low tire pressures will reduce mileage. All of the factors I noted above (and others) will contribute to any mechanical factors present. It's a good idea to research mechanical issues, but recognize that driving conditions are important.

 

[fred]

06' here with 163K.
Plugs just replaced, and I think its the first time the PCV was changed.
Aside from a bad coilpack #4 recently, I noticed I'm getting 20 now.
This is for general driving a lot of short trips, and mostly driving around town.
Before the plugs, PCV and coilpack, I was mostly 19, while luck to get 300m per tank in the winter (NYS).
As others have said, fill it up, drive until fuel light comes on and refill and divide miles by gallons.
Wouldn't hurt to get a cheap Android phone and the Torque (demo) app and check the various sensors.

 

[Madness!]

06' here with 163K.
Plugs just replaced, and I think its the first time the PCV was changed.
Aside from a bad coilpack #4 recently, I noticed I'm getting 20 now.
This is for general driving a lot of short trips, and mostly driving around town.
Before the plugs, PCV and coilpack, I was mostly 19, while luck to get 300m per tank in the winter (NYS).
As others have said, fill it up, drive until fuel light comes on and refill and divide miles by gallons.
Wouldn't hurt to get a cheap Android phone and the Torque (demo) app and check the various sensors.

I have an ELM327 and an android phone + app for looking at sensor readings. Things seem fine at least for the air/fuel sensors. Talked to an actual mechanic whom I know about it. Showed him screenshots and everything. Other sensors not so much...I had plans to test my camshaft position sensors but have kind of given up on them. I changed o rings on them earlier this year (they were leaking oil); turned out that the rear sensor is fused (melted) to the sensor. I nearly gave my fingers nerve damage before I realized that sensor was melted to the connector... Don't get me wrong everything works pretty good.

Some day I want to splice in a new connector and sensor, I have in fact bought said connector. I purchased some breadboard jumper wires and electrical solder to test those sensors but again, haven't done it. The plan was/is to solder three jumpers together with a lead off the middle and read the sensors off that lead while the sensor was plugged from the connector to the sensor. Essentially a solder/jumper lead passthrough. Now that I think about it if the jumper comes off one of the terminals while shes running that could spell disaster afaik. I am kind of rambling/thinking out loud here. I'd like to check readings on all the relevant sensors...

On a related note: why is the murano so friggin' heavy? Where is all that mass distrbuted? Does anybody know? I noticed the front doors are more sturdy and heavier than the rear doors for one thing. It seems really heavy up front given how I've looked around in it.

 

[I need coffee]

I had plans to test my camshaft position sensors but have kind of given up on them. I changed o rings on them earlier this year (they were leaking oil); turned out that the rear sensor is fused (melted) to the sensor. I nearly gave my fingers nerve damage before I realized that sensor was melted to the connector...

Are you sure you're disengaging the locking mechanism on the cam sensor connector correctly? Difficulty getting this connector off is not an uncommon problem because of the way it works: Harness connector to Camshaft Position Sensor

 

[sistermoon2500]

pro tip due to my experience... My VIAS valve 1 ( butterfly valve ) was always closed. after i fixed it. my fuel usuage dropped drastically!!! It now burns fuel like a v4 light car. and my power is improved too..
Please check if your VIAS is closed or open. when engine is idle. if its closed thats the issue. ( it doesnt throw any code )
please have a look at my thread. I went through it, even tho the fuel economy was not my issue. i was thinking that's normal to burn so much fuel. after i fixed it now i see the difference. FOllow my thread please

Does anyone know what position is the Butterfly valve...

If the picture in your above post is of your engine, your hoses are wrong. Watch the end of my video to see how they connect. The power valve hose should go to the center connection on the vacuum tank. Yours is going to the outer connection on that tank. The inside solenoid connection hose...

www.nissanmurano.org

 

[Madness!]

pro tip due to my experience... My VIAS valve 1 ( butterfly valve ) was always closed. after i fixed it. my fuel usuage dropped drastically!!! It now burns fuel like a v4 light car. and my power is improved too..
Please check if your VIAS is closed or open. when engine is idle. if its closed thats the issue. ( it doesnt throw any code )
please have a look at my thread. I went through it, even tho the fuel economy was not my issue. i was thinking that's normal to burn so much fuel. after i fixed it now i see the difference. FOllow my thread please

Does anyone know what position is the Butterfly valve...

If the picture in your above post is of your engine, your hoses are wrong. Watch the end of my video to see how they connect. The power valve hose should go to the center connection on the vacuum tank. Yours is going to the outer connection on that tank. The inside solenoid connection hose...

www.nissanmurano.org

This is something to investigate for sure. I noticed my MO's butterfly valve cap (the smooht black elliptical protrusion on the right side of the valve) can be rotated by hand very easily. Maybe I monkeyed with it too hard since I changed the plugs. IDK. I definitely yanked on the hoses pretty hard when I did that.

Right now, still no codes BUT I fixed a few vacuum leaks (air hose was loose), cleaned the MAF sensor,and put a new air filter in it. Still getting around 11 mpg... I am thinking since any vacuum leaks are fixed and its only getting worse... its gotta be fuel system related.

 

[MuranoSL2003]

This is something to investigate for sure. I noticed my MO's butterfly valve cap (the smooht black elliptical protrusion on the right side of the valve) can be rotated by hand very easily. Maybe I monkeyed with it too hard since I changed the plugs. IDK. I definitely yanked on the hoses pretty hard when I did that.

Right now, still no codes BUT I fixed a few vacuum leaks (air hose was loose), cleaned the MAF sensor,and put a new air filter in it. Still getting around 11 mpg... I am thinking since any vacuum leaks are fixed and its only getting worse... its gotta be fuel system related.

Have you used an app like Torque Pro to check the fuel trims? It can be helpful for understanding what is going on...

 

[sistermoon2500]

This is something to investigate for sure. I noticed my MO's butterfly valve cap (the smooht black elliptical protrusion on the right side of the valve) can be rotated by hand very easily. Maybe I monkeyed with it too hard since I changed the plugs. IDK. I definitely yanked on the hoses pretty hard when I did that.

Right now, still no codes BUT I fixed a few vacuum leaks (air hose was loose), cleaned the MAF sensor,and put a new air filter in it. Still getting around 11 mpg... I am thinking since any vacuum leaks are fixed and its only getting worse... its gotta be fuel system related.

it was positioned in right side? right as in toward windshield or toward headlghts? BTW yes you can easily move it with hands. but issue is teh vacumme.

 

[Madness!]

it was positioned in right side? right as in toward windshield or toward headlghts? BTW yes you can easily move it with hands. but issue is teh vacumme.

Yes the right side. I'm going to update this post title and original because I have SOLVED the problem! So happy!

 

[sistermoon2500]

Yes the right side. I'm going to update this post title and original because I have SOLVED the problem! So happy!

Yes the right side. I'm going to update this post title and original because I have SOLVED the problem! So happy!

Thanks for the update. You mention VID says...
WHats VID? how do u see accourate fuel usage? the one on the screen? or live on cvtz50 ?

 

[Madness!]

Thanks for the update. You mention VID says...
WHats VID? how do u see accourate fuel usage? the one on the screen? or live on cvtz50 ?

You do math, son.

Fill up. Set your trip odometer. Drive for a significant number of miles. Fill up again. Note the quantity of gasoline you put in. Divide that odometer mileage by the quantity of gasoline you just pumped. That's your MPG.

VID = Vehicle Information Display. Its the screen in your center console with all the functions like trip time, clock, HVAC and radio displays, gas mileage, etc.

 

[sistermoon2500]

You do math, son.

Fill up. Set your trip odometer. Drive for a significant number of miles. Fill up again. Note the quantity of gasoline you put in. Divide that odometer mileage by the quantity of gasoline you just pumped. That's your MPG.

VID = Vehicle Information Display. Its the screen in your center console with all the functions like trip time, clock, HVAC and radio displays, gas mileage, etc.

btw CVTz50 app shows real time... with my experience... If you can keep RPM under 2000. ur fuel usage is dropped under 10% ( 10 littre in 100km) on a level road. above 2000 since the buterfly valve closes more fuel will be burned

 

[Madness!]

btw CVTz50 app shows real time... with my experience... If you can keep RPM under 2000. ur fuel usage is dropped under 10% ( 10 littre in 100km) on a level road. above 2000 since the buterfly valve closes more fuel will be burned

I have no idea how said valve helps fuel economy so I won't argue with you.

But I have an update: I replaced both camshaft sensors last night; the damn thing started getting poor fuel economy again... And MAN its got some pep now!! Currently I'm at 157k miles on the MO and changing said sensors REALLY helped! Drove around for like two hours just revving it (within legal parameters of course) yesterday morning. It was super fun!! Car passed me doing 55 mph before I turned on to the highway. Put it in S mode and caught up with EASE and before I knew it! Was not expecting that!!

 

[MuranoSL2003]

Yeah, I've always found my 2 Muranos to be plenty quick. I've always had ample power for scooting/merging into traffic from a stop, and when passing.

I really cannot imagine needing anymore power. I've owned several very fast motorcycles, so I know what REALLY quick is like...