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Discussion Starter · #1 ·
Ok,
quick question.
Been reading some of your mpg results.
Now, I am borrowing a FX 3d rwd whilst my truck gets a little paint and then I trade for my own FX.
Anyway, been having a BLAST, but only been seeing about 19.6mpg, hmmm.
Then read a report by a guy who said he normally drives in manual shift mode as it is more fun and allowys fifith gear to be used more.
Well, driving today I put it in manual mode (several times to check consistancy). Anyway, I was on freeway or cruising at 65/70mph each time and when going to manual shift each time it showed fourth gear????
By using manual shift and putting it in fifth gear (only had short distance till home) already upped my mpg to 19.8mpg.
Is there somthing with the gearbox in auto which keeps it in forth gear too long?
Anyway, any observations will be greatly received.
**** I love this vehicle.
From the UK originally so am used to "pocket rockets" (gas prices WAY too high for V8's) and this is one of the best.
I call it the "Bulldog" due to it's stance " :)
Even my 9yo stepdaughter who was VERY sad to hear I was going to get rid of "Harley" is very happy about the "Bulldog" now :)
Nick
 

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You probably are in fifth in the Auto mode.

When you shift to manual mode it it downshifting to 4th automatically.
 

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if you think 19.5 is "only" what you are getting, then get ready for the reality of about 15 MPG :)

FX45 even less :)

this car is all about performance and your engine is going to suck gas to get there like a 6yr. old working the bottom of a milkshake glass with a straw ;)
 

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I do not think it is correct that the trans drops down when you go into manual(unless only in 5th)

The issue may be more torque converter lock up(TQ slippage is 3% or there about)TQ may be locked all the time in 5th vs in and out of lock up in other gears(typically lock up is engaged at about 40mph and dis engages based upon load

I really have not seen anyone focus on this detail of lock up,but my next Interstate trip of an hour more I will try 5th manual
 

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bradical said:
if you think 19.5 is "only" what you are getting, then get ready for the reality of about 15 MPG :)

FX45 even less :)

this car is all about performance and your engine is going to suck gas to get there like a 6yr. old working the bottom of a milkshake glass with a straw ;)
10.8 MPG on my 45
 

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Discussion Starter · #7 ·
Well anything is better than 10mpg or less with my Supercharged Harley!
 

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I have observed that my 45 always autoshifts down one gear everytime I shift into manual mode. I use it from time to time to speed up the downshift if I want to pass in a hurry. (5 to 4, 3 to 2, etc) It doesn't matter what gear you're in it will always drops one gear (maybe this is just my mind playing tricks).

I've also been paying a lot of attention to the MPG and have come to a few conclusions:

>Average MPG on the 45 after one month is 15.8
>Constant hard driving in town drives mileage down around 12 to 14 MPG.
>When cruising between 45 and 75 MPH with some stop and go, I average 17
>Freeway driving at a sustained 65 to 75 MPH yields 18+ MPG.
>Over 80 MPH the milage drops again, 85 MPH sustained yields 16.4 MPH and 90 MPH yields 15.8.
>85 MPH the tach in 5th gear shows 3,000 RPM
>90 MPH the tach shows about 3,300 RPM

I have to assume that wind resistance is what's killing the mileage over 75 MPH.

If I wanted great milage I would have bought a Prius (51mpg). As my father used to say if someone asked what kind of mileage his Cadillac got, "If you have to ask you can't afford it".

I drove large SUV's before the FX and am used to 14 to 16 MPG. Maybe the milage is actually why they clasify the FX as an SUV. I can imagine that new FX owners coming from a Honda Civic, or any other sedan for that matter, would go into shock when they start filling up the FX45 with Premium gas. :shock: 8)
 

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Dakine said:
Ok,
quick question..., I was on freeway or cruising at 65/70mph each time and when going to manual shift each time it showed fourth gear????Nick
It's all logical. Think a little harder, drive it a little more aggresive then you'll understand why they (the engineers) want it lower to fourth when shift the trans. to Manual mode at crusing speed, think.
 

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Heh. What's this "D" y'all claim the transmission has? ... I don't think I've ever seen it!

And yeah, the tranny drops a gear when you first put it into ManuMatic mode.
 

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there are two kinds of programs that are currently in place on the inifiniti line. the first is was is on the older G35s (not sure its used anymore). this one, the trans will drop into a lower gear only from 5th, yet stay in the last gear you were driving in even if you stop. (i.e.. if you are in 3rd and then stop, itll stay in 3rd and auto shift TO third again on start and stay there).

the other one is on all the other cars and the FX included. it will downshift from 5th to 4 all the time and automatically drop to 1st on stop of the car. the big thing here is that im not sure if it drops down on other gears. in fact, i have been in 3rd in auto mode, and slapd the shifter over and it actually will UPSHIFT to 4th.

with some hard driving, i think the ECU will adjust to this though and eventually it will know NOT to upshift ever! :D
 

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PINITI-FX said:
dual .ORG stickers????? Pics.!!!!
yeah...i put one on each side this time. last time i put it on the left rear window, but the problem is that im always passing people in the left and noone see it :D this time i put one on both sides so you always see one as i blow by :car9:
 

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bradical said:
the other one is on all the other cars and the FX included. it will downshift from 5th to 4 all the time and automatically drop to 1st on stop of the car. the big thing here is that im not sure if it drops down on other gears. in fact, i have been in 3rd in auto mode, and slapd the shifter over and it actually will UPSHIFT to 4th.

with some hard driving, i think the ECU will adjust to this though and eventually it will know NOT to upshift ever! :D



Mine will only downshift to 5th from 4th. It doesn't downshift in any other gear. If I'm in the automatic mode in 4th gear and move the shifter to manual mode, it stays in 4th. 3rd the same.
Were you at a high rpm in 3rd when it upshifted to 4th?

Maybe I need to drive it a little harder :twisted:
 

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yeah, its rare and when im at the top of the gear. once i break the car in itll go away like it did on my old 35.

i did verify today that it WILL downshift from any gear though like kenny sez. if you're moving slow and slap it over it will go into 2nd or 3rd depending on speed...
 

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Punisher said:
Silver Bullet said:
I have to assume that wind resistance is what's killing the mileage over 75 MPH.
You don't think it'd be attributed to the higher rpm and engine working harder?
3,000 RPM is hardly working for the FX. As you increase speed the RPM's of course will go up, but there remains a direct relationship between the RPM's and the distance you travel. So in my mind, if the engine is working harder it as to be because of resistance. I'm not an expert but this is a pretty big car pushing a lot of air. As ShadyJC noted in his remarks, his mileage increased when he lowered his FX, once again an issue of wind resistance.

I do wish the FX had a 6th gear for flat cruising. Other makes are starting to move that direction, including Audi. 8)
 

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I was testing driving this today and could not get the car to downshift from 4th to 3rd, 3rd to 2nd etc. swapping back and forth from auto to manu-matic mode. It did however go from 5th to 4th every time. Maybe speed and RPM's have something to do with it. But, when I was going about 40mph, you would think it would automatically go from 4th to 3rd when I flip it over, but mine does not.

What gives? Anyone have the answer to this?
 

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I'm sorry- when I said "does drop a gear when you put it into ManuMatic mode", that should have had "only in 5th down to 4th" in it. Many times I'm already in 2nd range when I drop into MM mode, and it doesn't drop me into first.
 
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