Mileage - Help, freaking out a little

[xkursion]

Hi everyone,

So ... if you read my welcome post I just traded in my 2002 Xterra and 2008 Altima coupe for a 2012 Fronty CC Pro4x.

First off... I researched this so no "search and we told you so's"... but I'm getting horrible mileage in my new truck. Just finished my first 1/2 tank and am getting 17.4 L/100km. This is mostly city driving, but all free moving, no waiting in traffic, and I haven't been idling the truck like crazy. I'm being gentle on it, not gassing it everywhere. This is worse than my 2002 Supercharged X.

I expected it to be worse than my Altima of course... I was getting 9.5L/100 ... but I would flog that car all the time. I was expecting to get 13-15 L/100 in the truck, 17.4 is a little up there. I can just imaging what it would be if i was sitting in traffic.

Did anyone notice if your mileage improved after the truck broke in some? Or is this normal and I'm gonna cry myself to sleep hahaa.... I know it's only the first 1/2 tank, but I'm freaking out man!

Thanks,
Kris

[Scotto]

Change the two front O2 censors. You can see them when you pop the hood. OK, let's backtrack:

Pull a sparkplug from bank one and another from bank two. Are they black; is one black? Or both? If so, move to step one (change the O2 on that bank, or both if need be). Mine did this in the spring, and had mileage like you. I was getting about 300Kto a tank for a bit. Like you. I only did one, but suspect as I creep back to 14L/100Km that I ought to change the other O2 as well.

O2s are pretty cheap - like $60- (you don't have to go Nissan, your trusty neighbourhood mechanic can do it) and my mileage went up (down?) to something like 11.5L/100. I still pull about 500KM before a refill, but the fuel light is on, but I had it really good for about 4 months with just the one 02. Time to do the other.

The O2s won't throw a code. But the ECM sees something up and starts to throw fuel in to correct the bad readings. is the response from the dumbass machine in your truck when the O2 goes weird.

You can get her good again. No worries on this one.

Scott

[Bender]

I don't think he is going to change anything on a brand new truck.


Hang in there, as the tight tolerances loosen up on the new motor it will get better. I can tell you this, you will not achieve what the brochure said you will. Those numbers are based on perfect conditions. I hated dealing with irate customers at Nissan about fuel consumption!

[Scotto]

Woah - I just saw you have a 2012. I read it as 2002.

Mmmm. I'd still go with my thoughts, but if it's 2012, a year I haven't even experienced yet, I might use my trusty warranty. Get that bugger computerized by Nissan.

[xkursion]

yea... not changing the O2 sensors on a truck I picked up last week

I know brochure values are garbage, it lists 9.8 hwy and 14.8 city. I figured about 15 with about a 80 city 20 hwy split.

Here's hoping. I looked around and people seemed to be getting 15-19 MPG or 12-15 L/100km.

[Bow_Tied]

This time of year the open loop warm up mode will take longer and that naturally uses more fuel. I think the "winter gas" also screws you for a MPG or so. I find I am down 2-3MPG in the winter time because of those two things. Combine that with the break in period maybe.....

[Bow_Tied]

http://www.fueleconomy.gov/feg/PowerSea ... rchtyp=ymm" onclick="window.open(this.href);return false;

14MPG = 16.8L/100km

[Scotto]

I always forget about the winter gas thing. They add sh!t to keep it from freezing. And then the open loop...

In the morning there is this lovely haze of white fog behind my truck as it gets up to temp. And the smell of unburnt fuel. Might as well as use $20- bills to start the wood stove.

[xkursion]

You may have a theory from the open loop. I wonder if the tables it uses internally are programmed on "learned". Maybe the combo of the truck being new and not broken in are yielding higher than average fuel burn based on inadequate data in the tables.

I know what the rated city mileage, but I do some "highway" style driving thrown it, so I was expecting to get somewhere in there. Based on fueleconomy.gov's reported "real world average" users report 17-19 mixed use. I know this is without cold, and new, etc, etc.

Well I'll hope for the best, not like I'm giving it back... love this truck. Just a little concerning to sit at a stop light and see the avg l/100km climb ... 17.4.... 17.5.... 17.6 lol

Can anyone chime in with what they're getting on their 05+ frontier v6.

[Bow_Tied]

there is a learning mode I think but that would be outside of the open loop which is entirely engine temp dependant. If you have an auto trans open loops prevents the lock up part of the torque convertor from engaging which makes the engine rev higher on the highway (all assuming these newer vehciles behave as I the ones before it do).

[Simon]

Stick with what Bender said. The first 1000+ kms won't be as good as it will get once broken in. It'll improve further after the winter symptoms the other lads have mentioned.

[Snafu]

Ditto what Bendy pants said. New engine needs to be broken in...I'm jealous!

I hated dealing with irate customers at Nissan about fuel consumption!

Not just Nissan. Everyone's mileage numbers are under ideal test conditions...probably on a tread mill with controlled air temp, humidity, etc. It is suppose to be a standardised test for comparing cars/trucks.

Might as well as use $20- bills to start the wood stove

Spend it on a block heater to help warm it up first

Block heater might help too to get it out of the warm-up loop sooner.

[petespath]

tire pressure

.02 cents.

(post count?)

[Dowser]

My thoughts are to allow time to break in as well. Tire pressure is something to remember especially when winter weather rolls in the air pressure changes and you end up a bit low, but if the vehicle was only purchased last week, I'm sure a PDI was preformed and tire pressure would definitely be covered then.

How is Nissan with flash updates on new vehicles? I know at Chrysler people came in routinely for flash updates all the time, especially when Cummins put out the new 6.7L and things like Fuel Mileage would change a tiny bit sometimes. I haven't got a clue what is under newer Nissans though since I'm piss poor and don't need to depress myself further by keeping up with new products.

Just a thought.

[Snafu]

...for every 10° Fahrenheit change in air temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).

So about every 5°C change tire pressure changes by ~1psi.

[studum]

Funny I read this. Just got a couple messages the other day from fellow "car guy" buddies saying they thought the winter gas was out. I've taken a noticeable hit already in my already thirsty rig. It is what it is though...

Between the cold open loop, the new truck, and the winter gas I think you have a perfect storm. Double check your tire pressure just for cheats and wiggles.

[xkursion]

yea, already seeing a noticable improvement... down to about 16.9 - 17.2 when out and about. As more mileage builds into the calculations it also helps the shock of seeing it rise quickly while sitting at stop lights, etc.

I think by the time everything breaks in I'll be in the 16 range, which I'm happy with.

[Bow_Tied]

You'll need a few tanks to establish a good baseline I think

[Relic]

09 KC Pro4X automatic here, I was never that brutal brand new. Highway I get around 10-11L/100, city 14L/100. I've seen threads like this before on Club Frontier.

[ironman]

Well I never see good mileage when towing and I got the 4.0L there are a few sweet spots 80 k and 110 Km. the one thing I did to get better mileage was a 2.5 inche cat back with a high flow muffler and got rid of the Y Pipe. If you are trusting the computer in the truck just know its close but only if u reset it every time u gas up.