Nissan Murano Forum banner

1 - 20 of 38 Posts

·
Premium Member
Joined
·
7,136 Posts
Discussion Starter · #1 ·
Maybe it is just me. but...................

I normally get 23 mpg on my way to work with premium gas doing about 70 mph average. My commute to work is 43 miles one way on mostly flat roads except for a two mile uphill piece which is then made up for by its two mile downhill return.

Ever since my last visit to the dealer couple of weeks ago my gas mileage had substantially dropped, down to 21 mpg. I think one of the things they said they had done was to adjust the idle speed???? I always thought the idle speed was computer controlled but I could be wrong.

This morning I reset the display on the flat portion of the road to measure the mpg without interference from any city driving I had recently done. At first the display showed 24.7 mpg but in a matter of 10 minutes it dropped to 23, 22, and then it seemed to stablize around 21.7. I was :3: and :confused:

Then I rememberd something I had read on this board. Something about momentarily flooring the gas pedal which supposedly resets the computer...or something along those lines. I don't remember excatly.

So I did it. I floored the gas pedal, the MO took off, and then I let it coast back to the speed I was driving at (67 mph). By this time I was about 20 miles away from work.

To my surprise over the next few minutes I saw the display change to 22.3, then 24, then 25.3 !!!! The best part was when I got to work some 15 minutes later it was still 25.3.....:claphead:
 

·
Registered
Joined
·
78 Posts
I'm a little confused. Did flooring the MO for a sec actually cause if to run more efficently and get better milage. Or did it just trigger some sort of computer reset so that you were getting better MPG calculations out of the computer???

Pacmo
 

·
Moderator
Joined
·
5,244 Posts
zeb,

if only that so easy......;)
 

·
Premium Member
Joined
·
7,136 Posts
Discussion Starter · #5 ·
pacmo said:
I'm a little confused. Did flooring the MO for a sec actually cause if to run more efficently and get better milage. Or did it just trigger some sort of computer reset so that you were getting better MPG calculations out of the computer???

Pacmo
I know it sounds crazy, and maybe it is just in my head. I really don't know. But I do recall something mentioned on this board somewhere. Maybe it was a joke. I can't say. But whatever it was I tried it and it seemed like it worked for the short test duration until I got to work.

This morning's results could have just been a coincidence. Maybe engine and tranny warming up had to do with it. All I know is that the dramatic result occured only after I floored it. But what if flooring it somehow reset the throttle positioner or something else????? Or maybe it just undid whatever "idle adjustment" dealer had done...

On the way back home today I will see if the better gas mileage still holds up. I have relatively the same road conditions to travel on, but I will see heavier traffic and warmer weather.
 

·
Registered
Joined
·
12,512 Posts
I had the same problem but corrected it in a different way - I used the auto-down feature to lower the front windows, turned on the rear defroster, and then selected an AM station. (Of course I rolled the windows back up. I'm no dummy.) Lo and behold my mileage increased! :2:

zebelkhan-

Boy, will I look like an idiot if what you are saying turns out to be true.

-njjoe
 

·
Mr. 3 K, 3/3/5. 5K,10/5/7
Joined
·
4,994 Posts
IMO

The method That MR. Z describes lets the CVT settle into to a different final ( and more economic) drive ratio that achieved before doing his method. So yes the Mo actually gets better fuel economy and does run more efficiently.

Grip
 

·
Premium Member
Joined
·
7,136 Posts
Discussion Starter · #9 ·
Re: IMO

GripperDon said:
The method That MR. Z describes lets the CVT settle into to a different final ( and more economic) drive ratio that achieved before doing his method. So yes the Mo actually gets better fuel economy and does run more efficiently.

Grip
Thanks for backing me up on this Don! And yes, it is official. On the drive back from work, temp 61F, average speed 70 mph, except for about 5 miles when I could not do faster than 30, with two complete stops, going over the same grade except on the oposit direction. I did not even warm up the engine as I wanted it to be excatly how I usually drive.

Here are the results:

Started from work with display now showing 22.7. That must have been as the result of the short "city" driving I had from freeway to work. I entered freeway and increased speed to 70 and and set the cruise. By the time I got home the display showed 24.7 mpg.....:18:
 

·
Registered
Joined
·
12,512 Posts
zebelkhan-

O.K. I'll admit it. Your method works (as crazy as it sounds). Mine doesn't.

:6:

-njjoe
 

·
Registered
Joined
·
38 Posts
I just noticed something similar the other day. I noticed that in many cases, if I deliberately coast on flats or downgrades, the RPM's go up a bit. I'm sure it's a CVT thing. If I then give it a little throttle, the RPM's drop down. I didn't do a MPG comparison over distance but I'm sure it will make a difference. I'm sure speed control works against the MPG in the same manner. If you're going to use speed control, assist it with a little throttle when it automatically backs off. It doesn't take much.
 

·
Premium Member
Joined
·
7,136 Posts
Discussion Starter · #12 ·
njjoe said:
zebelkhan-

O.K. I'll admit it. Your method works (as crazy as it sounds). Mine doesn't.

:6:

-njjoe
Well, it is just possible that something was wrong with my set-up which has somehow been corrected. As I mentioned in my first post, ever since the dealer "set the idle" (whatever that means) in my MO I started getting terrible gas mileage. Maybe it was a coincidence, or as as GripperDon said something adjusted itself in the CVT. So if your car is already running at its best, there is nothing to improve.

All I know is that I am on my second day of this, with 130 miles under my belt, and when I stopped at work this morning, display showed exactly 25.0 mpg - BTW this leg included about 4 miles of slow city driving, rest was on the freeway @ 65 mph.
 

·
Registered
Joined
·
4,077 Posts
Re: IMO

GripperDon said:
The method That MR. Z describes lets the CVT settle into to a different final ( and more economic) drive ratio that achieved before doing his method. So yes the Mo actually gets better fuel economy and does run more efficiently.

Grip
Doesn't the CVT always operate in a mode for efficiency? Isn't that the point of a CVT?
 

·
Premium Member
Joined
·
8,368 Posts
This is one the craziest ideas I've ever read, but I don't doubt zeb's word for a minute. Whatever the reason, it appears it works for him, and thats all that matters.

I've heard the idea of flooring it after adding a bottle of fuel injector cleaner like Chevron Techron Concentrate or BG44K, though, to "blow out the carbon" (as the Texas Car Doctor likes to say).
 

·
Mr. 3 K, 3/3/5. 5K,10/5/7
Joined
·
4,994 Posts
It's all logical

And reasonable. The CVT has a "Dead Band" just like a thermostat. The zone that it does not regulate in. On a thermostat say it's 2 degrees F. For the CVT it depends on which direction the variable width pulleys are coming from open or closed. So the CVT reaches the deadband from alternate directions. Leaving the effective drive ratio of the transmission in a different place. Take a look at the Tach and see if you can detect the differing RPM's for the same speedo reading. I don't have my MO no MO so I can't do it myself. This is what it is doing.

Grip
 

·
Registered
Joined
·
1,582 Posts
Raise your hand if you're gonna punch it on the way home tonight....:18:

Can't hurt, can it?
 

·
Registered
Joined
·
78 Posts
Mr3Putt said:
Raise your hand if you're gonna punch it on the way home tonight....:18:

Can't hurt, can it?
I'm in :awais:
I just hit 1250 miles on my MO on the way in to work today. So I am now free to take the RPMs over 4000!

pacmo
 

·
Premium Member
Joined
·
7,136 Posts
Discussion Starter · #18 ·
Mr3Putt said:
Raise your hand if you're gonna punch it on the way home tonight....:18:
If this workd for you guys then I want royalty...................:2:
 

·
Premium Member
Joined
·
8,368 Posts
:4:
 

·
Moderator
Joined
·
5,244 Posts
zebelkhan said:

If this workd for you guys then I want royalty...................:2:

No problem, just post your bank account number......:22:
 
1 - 20 of 38 Posts
Top