[eckemoff]

My 2009 SE Crewcab v6 4x4 auto is getting between 14-16 using regular 87 fuel with 10% ethenal MPG at mostly highway driving (maybe 20% city), going about 60-65, or 75-80 on the interstate (maybe 5-10% of the time).

I only have 5500 miles on it and am completely stock as far as mods.

I did get about 17 MPG using 10% ethenal/ 89 fuel driving conservatively.

I am in North Carolina close to Virgina. Almost every single gas station uses ethenal now or will in the future (it makes gas prices seem cheaper.... though cars get less MPG and preform worse....ironic marketing).


Is this normal? PS it has been winter and really cold... I have been told this can decrease MPG by 1-3.


Also, I have been told that all Nissan Frontiers 2005+ should be using 87... not high and definitely not lower. But I have also heard 89 is recommended by dealers. The manual states 87 pretty clearly.

I am told that it takes a 10-30k miles to break a new car in and get the appropriate mileage, and that MPG for a frontier will be 1-3 lower than normal. I don't really buy this though.... the manual states 4k miles or first oil change is all that is needed.

It actually seems that about right that I only get 14-16 MPG because EPA (19 MPG max) tests ignore environmental conditions, simulate grandma-drives, and follow speed limits. All of those conditions ignored will decrease mileage by about 3.

What kind of mileage are you guys getting and with what fuel type. Preferably without mods.

The one time i tried 89 fuel without ethenal, I did notice the truck seemed more powerful, the RPMs were a hair less, and the engine did not have to get high RPM to accelerate and shift.


What do yall think?

 

[dubie2003]

I think you are about right. There are tons of threads about this same topic that you should probably read thru if you care to. They will answer all your questions.

The basic set-up is that running 89 is a bit better then the 87 since it helps with you get into the high rpm range and it helps a little with mileage.

The winter gas blend isn't going to help so you are right, 1-3mpg decrease.

The E10 crap is also going to kill the mpg, a few at most.

All of this together with the fact that you are 4wd, you are going to get semi-crappy mileage compared to others.

Lastly, the temp being close to freezing is going to cause issues since it will take a little longer to warm up and the motor will naturally run a little more fuel to increase help increase temps during the warm-up period.

 

[colin123]

quote the manual from your truck for 09

FUEL RECOMMENDATION
Use unleaded regular gasoline with an octane
rating of at least 87 AKI (Anti-Knock Index) number
(Research octane number 91).

quote from 08 manual

For 4.0L engine.
NISSAN recommends the use of premium unleaded
gasoline with an octane rating of at least
91 AKI (Anti-Knock Index) number (Research
octane number 96). If unleaded premium gasoline
is not available, you may use unleaded regular
gasoline with an octane rating of at least 87 AKI
number (Research octane number 91), but you
may notice a decrease in performance.

quote from manual for 07

For 4.0L engine.
NISSAN recommends the use of premium unleaded
gasoline with an octane rating of at least
91 AKI (Anti-Knock Index) number (Research
octane number 96). If unleaded premium gasoline
is not available, you may use unleaded regular
gasoline with an octane rating of at least 87 AKI
number (Research octane number 91), but you
may notice a decrease in performance.

quote from 05 manual

For 4.0L engine.
Use unleaded regular gasoline with an octane
rating of at least 87 AKI (Anti-Knock Index) number
(Research octane number 91).
For improved vehicle performance, NISSAN recommends
the use of unleaded premium gasoline
with an octane rating of at least 91 AKI number
(Research octane number 96).

09 was the first year that the manual changed from saying to use premium (atleast 91) and to only use 87 where premium was unavailable. all other manuals before it say not using atleast 91 will decrease performance. not sure why they changed the manual since the motors, hp rating, ect have not changed. winter will cause your mpg to fall due to a much cooler and dense air charge, your motor has to compensate to keep its optimum air fuel ratio by adding more fuel and on top of that winter blend gas has roughly 1.7-2% less energy in it then summer blend gas which will contribute to lower mpg since it takes more fuel to get the same energy. but when it comes down to it i don't think most people use higher than 87 in their frontiers regardless if they have your manual (09) or one of the earlier ones and i'm not sure if anyone has done any conclusive data logging to see a difference in economy. what happens is the optimum tune in the ecu wants to have 91 octane to give peak performance but it does have the ability to adjust to lower octane fuels by way of retarding some timing and so on. people using 87 in some areas have complained of engine pinging on occasion and when the computer sees this happen it goes to a very retarded fuel rich tune so as to eliminate detonation. when people have taken them in for this the dealer asks what fuel do you use, "87" then the dealer has told them to go up to atleast 91 to eliminate it and problem gone. not all areas (climates) will have the engine needing 91 to get to its optimum performance. i go with the manual (i'm an 07) and use premium and even with mods which have hurt my MPG i get a combined 17.5-18 mpg and and have gotten a combined 23 mpg with one tank of gas when i take trips to see my dad in Tennessee. when i go i drive 75-80 mph the whole way since most speed limits are 70 mph on the way there and one tank of gas gets me the 375 miles there, lets me drive a round for almost a week then gas up and come home. during winter my mpg drop to about 15 mpg combined sometimes 14. in winter if i drive nothing but in the city i'll get 12.5-13. any fuel without ethanol is going to get you better results but fuel without 10% is pretty hard to come by since is many states are now requiring it. oh and yes many motors can take up to 20k miles before they are fully broken in. it is recommended when going forced induction on a factory naturally aspirated motor you should do so before the 20k mile mark and preferably before the 15k mile mark since the motor is not 100% set broken in and will still adjust nicely and break in to the forced induction. you should however have your optimum fuel economy from the motor by the time you hit the 10k mile mark most likely sooner. hope some of this was some help to ya. enjoy the new truck

 

[colin123]

on another note all years of xterra which have the vq40 say the same as the 09 frontier manual and make no mention of premium even though same year frontiers with the same motor do. on top of that the pathfinder manual recommends 91 for best performance too with both the vq40 and vk56. very odd. and none of the manuals for either say anything about if either will give you better milage. i suspect that as long as you are not getting detonation (which would cause it to go rich and retard timing) then your MPG for either grade will probably be about the same little to no difference.

 

[eckemoff]

I think you are about right. There are tons of threads about this same topic that you should probably read thru if you care to. They will answer all your questions.

The basic set-up is that running 89 is a bit better then the 87 since it helps with you get into the high rpm range and it helps a little with mileage.

The winter gas blend isn't going to help so you are right, 1-3mpg decrease.

The E10 crap is also going to kill the mpg, a few at most.

All of this together with the fact that you are 4wd, you are going to get semi-crappy mileage compared to others.

Lastly, the temp being close to freezing is going to cause issues since it will take a little longer to warm up and the motor will naturally run a little more fuel to increase help increase temps during the warm-up period.

How is being 4x4 going to make my mileage much worse if I don't use 4x4? I've heard that 4x4 is less than 1 MPG difference.

PS, is it a bad idea to get an engine programmer with 6k miles?

 

[dubie2003]

You should spend some time researching the different types of 4wd systems. The one used in the 2nd gen Frontier's causes a bit of drag. The front diff is always spinning, the Dshaft is spinning and the Tcase is disengaged but spinning. This causes drag and heat and both help decrease mileage.

 

[eckemoff]

You should spend some time researching the different types of 4wd systems. The one used in the 2nd gen Frontier's causes a bit of drag. The front diff is always spinning, the Dshaft is spinning and the Tcase is disengaged but spinning. This causes drag and heat and both help decrease mileage.

That is lame. Would this decrease performance as well because power is being used to spin a useless differential (ie, a 2wd frontier can accelerate better)?

 

[Fear Night]

I have been doing experimenting with running 93 vs 87. I was hoping 93 would save me money despite costing more at the pump. I would also be able to run my Hypertech premium tune which is a beast. Here are my results:

93 Octane (w/ Hypertech premium fuel tune):
Fuel Cost: $2.95
Avg. MPG: 18
Monthly cost: $177.57 (assuming normal commute, 80%+ interstate)

87 Octane (w/ Hypertech regular fuel tune):
Fuel Cost: $2.65
Avg. MPG: 17
Monthly cost: $168.90 (assuming normal commute, 80%+ interstate)

So, running regular saves me about $10/mo even though premium gives 1 mpg better. I still haven't decided whether the extra performance is worth an extra $10/mo. I would be tempted to drive harder anyway and probably average 16 mpg.

Another thing I have been experimenting with is drafting. I have seen upwards of 22-23mpg if I stay behind semi trucks on the interstate (leaving a reasonable distance, of course).

 

[dubie2003]

That is lame. Would this decrease performance as well because power is being used to spin a useless differential (ie, a 2wd frontier can accelerate better)?

The motor isn't powering the front diff unless you are in 4wd. There is drag being created by the front diff thou thru the CV joints to the diff with ring/pinion thru the Dshaft to the Tcase thru its gear.

This is also why it is stupid to buy a 4wd unless you will actually use it. I know people say 4wd truck have a better resale value but the loss of mpg during its ownership and not to mention the additional maintance kill that extra profit.

 

[eckemoff]

I have been doing experimenting with running 93 vs 87. I was hoping 93 would save me money despite costing more at the pump. I would also be able to run my Hypertech premium tune which is a beast. Here are my results:

93 Octane (w/ Hypertech premium fuel tune):
Fuel Cost: $2.95
Avg. MPG: 18
Monthly cost: $177.57 (assuming normal commute, 80%+ interstate)

87 Octane (w/ Hypertech regular fuel tune):
Fuel Cost: $2.65
Avg. MPG: 17
Monthly cost: $168.90 (assuming normal commute, 80%+ interstate)

So, running regular saves me about $10/mo even though premium gives 1 mpg better. I still haven't decided whether the extra performance is worth an extra $10/mo since I would be tempted to drive harder anyway.

Another thing I have been experimenting with is drafting. I have seen upwards of 22-23mpg if I stay behind semi trucks on the interstate (leaving a reasonable distance, of course).

How much has the hypertech helped you? I see you also have a moded intake and exhaust.

Total stock and using 89 gas I get 17 MPG. (80% 65 MPH highway though)

 

[Fear Night]

How much has the hypertech helped you? I see you also have a moded intake and exhaust.

Total stock and using 89 gas I get 17 MPG. (80% 65 MPH highway though)

From what I can tell the Hypertech hasn't helped my MPG much, if at all. I'm fine with that though, extra power without hurting MPG is what I wanted. They do make an ECON version which is supposed to help MPG so I can't give any experience with that; I have the Max Energy Power model.

 

[eckemoff]

The motor isn't powering the front diff unless you are in 4wd. There is drag being created by the front diff thou thru the CV joints to the diff with ring/pinion thru the Dshaft to the Tcase thru its gear.

This is also why it is stupid to buy a 4wd unless you will actually use it. I know people say 4wd truck have a better resale value but the loss of mpg during its ownership and not to mention the additional maintance kill that extra profit.

A truck without 4wd really limits that it is a truck. It makes it more of a poor-man's SUV...

Plus being trucks are lighter in the back, driving a 2wd in bad weather or off-road is just asking for trouble.

4wd may not be needed 90% of the time, but the 10% that it is, it is a real saver. I think it is worth the 1 MPG difference.

Same argument: "I think wiper blades are useless because they cost money, it doesn't rain that much here, and they weight extra..." Then it rains and you're cursing yourself for having them. But yeah... getting 4wd is a bit more expensive than wiper blades.

 

[devious1]

2006 SE 6 cylinder 2wd

The last time I check mine it was getting 24mpg with a mix of highway and city. It does have a K&N air filter and synthetic oil. That was on 87 without the "Ecrap". Most of the time I use 89. I know, I know Nissan recommends against it and it wasn't untill 100,000 that I started but 87 now sets off my CEL so...

 

[kannibul]

A truck without 4wd really limits that it is a truck. It makes it more of a poor-man's SUV...

Plus being trucks are lighter in the back, driving a 2wd in bad weather or off-road is just asking for trouble.

4wd may not be needed 90% of the time, but the 10% that it is, it is a real saver. I think it is worth the 1 MPG difference.

Same argument: "I think wiper blades are useless because they cost money, it doesn't rain that much here, and they weight extra..." Then it rains and you're cursing yourself for having them. But yeah... getting 4wd is a bit more expensive than wiper blades.

I agree with this...I had a 2WD ford ranger for years. I decided that I would go with 4WD truck when it came time to replace it....which I did in Jan w/ my Frontier. I couldn't be happier. We had a couple of snow storms afterwards and that totally justified it in my mind. World of difference. I complaim about the mileage...but it's a truck. A big heavy truck that has an engine 1/3rd larger than my ranger's engine, and going off that, it's about right.

2006 SE 6 cylinder 2wd

The last time I check mine it was getting 24mpg with a mix of highway and city. It does have a K&N air filter and synthetic oil. That was on 87 without the "Ecrap". Most of the time I use 89. I know, I know Nissan recommends against it and it wasn't untill 100,000 that I started but 87 now sets off my CEL so...

If 87 is tripping your CEL, then you may have other issues (like a bad knock sensor, maybe the timing is stuck advacned a bit, etc).

87 shouldn't trip a CEL...

 

[VoodooSaint]

I have been doing experimenting with running 93 vs 87. I was hoping 93 would save me money despite costing more at the pump. I would also be able to run my Hypertech premium tune which is a beast. Here are my results:

93 Octane (w/ Hypertech premium fuel tune):
Fuel Cost: $2.95
Avg. MPG: 18
Monthly cost: $177.57 (assuming normal commute, 80%+ interstate)

87 Octane (w/ Hypertech regular fuel tune):
Fuel Cost: $2.65
Avg. MPG: 17
Monthly cost: $168.90 (assuming normal commute, 80%+ interstate)

So, running regular saves me about $10/mo even though premium gives 1 mpg better. I still haven't decided whether the extra performance is worth an extra $10/mo. I would be tempted to drive harder anyway and probably average 16 mpg.

Another thing I have been experimenting with is drafting. I have seen upwards of 22-23mpg if I stay behind semi trucks on the interstate (leaving a reasonable distance, of course).

So around $120 a year for a few more ponies, and a slightly cleaner fuel and engine? Not too terrible of an idea in the long run...

 

[Higgs Boson]

I am running 93 octane and have the front left corner of my airbox cut out and a two degree timing advance. I have a KC 6 spd 4x4. My truck has 9500 miles on it right now. I drive about 75% highway and was getting 21-22 mpg. Over this winter I have been getting high 18s.

 

[HOTCHKIS]

So far here in FL with no stop and go driving I'm getting 19-20 mpg! I also get 1 mpg better with the 89...will have to try 93 and see!

 

[JNR]

4x4's are heavier and generally have larger, wider tires and sit a little higher (for hwy mpg), so it's to be expected they will get less mileage, even in 2wd...Small price to pay for when you need it, or use it. Also, many people put bumpers, sliders and other heavy things plus the gear onto their trucks so you'll get worse mileage too...Add to that the highway gears for the city we have (3.36 for auto and 3.69 for manual, although a little more suited), plus they are essentially bricks in the wind and no wonder these don't get great mpg (they do weigh ~4500 lbs!). But, really, they don't get bad mileage either...they are trucks after all and have decent power (for a 6 cyl).

As for the older models (pre-2009), I ran across an interesting thread on an xTerra forum, iirc, where they were putting the DT LT's on their 2009 I think it was and only gained 5 hp on stock ecu, where the 2008 claimed to gain 26 hp on stock ecu...I'm sure the latter was exaggerated, but the point is that they were talking about how the 2009+ ECU's don't "learn" the mods as well as the older one...So, this leads me to believe that they recommended 91 octane on the older ones, since the tune was able to compensate for the advance timing that the 91 would allow (vs. 87 where it would retard it to keep it from detonating)...Now, why the hp is rated the same on the newer ones using 87, I don't know, other than maybe they changed the tune somehow else to make this up, just guessing...Is the compression ratio, cams and everything else identical between say a 2008 and 2009, or 2010, etc.? Or, I suppose it's even possible they realized that they didn't really *need* 91 octane afterall...

With that said, say it is true, then 91 would be a waste of $$ if the ECU doesn't allow any extra timing, etc. from 87, or if the 87 is good enough antiknock quality to prevent detonation...That is really the only reason you go up in octane. Higher compression (N/A or forced induction being compressed air forced into the cylinders) needs more anti-knock properties, apples to apples, but we also have aluminum heads/block and ECU tune (vs. a carb and non-ECU), so 9.8:1 is not really that high like it once was. It is getting close though to needing 91, IMO, for full potential but again it all depends on the program parameters and allowances (ECU).

I was happy when I first got the truck that it only needed 87 and non-synthetic fluids (except the diff, iirc on the M226), then I read about the older ones recommending 91 but being able to run 87, so thought maybe this 2011 was the same and 91 would allow full potential. Then I ran across that thread and also haven't noticed any difference since I've been running 91, so think I'll go back, as 20 cents a gallon adds up if it does nothing.

Of course, once you change the tune with say a programmer, then 91 would be beneficial for sure and more worth it. One thing that pisses me off is this ethanol BS!!!

Oh yeah, keep in mind after the engine ages with mileage and esp. low speed, stop and go, etc., it will build up carbon in the combustion chamber (no matter what type of gas you use, it's the nature of it) and then it could require you to run higher octane to prevent detonation, since it can get hot enough and stay hot enough to fire it prematurely before the spark...Add to this that crappy ethanol that can gum up the fuel system and we're constantly running against the gauntlet trying to keep these things running like new.

 

[CT_Nismo]

Premium Fuel vs. 87 Octane: A Two year Study

There are many posts that speak about the benefits of using premium fuel with the 4.0. The data is often very limited and cannot be compared to another driver/truck's experience. Is there a mpg improvement with premium? There is an answer but it takes a controlled experiment to develop believable answers.

Over a two year period, I ran 93 octane in the first year and 87 octane in the second. The huge database on both sides of the argument provides credibility to the answer. It will surprise you.

First the setup:

1. Truck: 2006 Nismo 4.0 liter
2. Start miles: 26,000 (broken in)
3. On Road/off road: 100% on road
4. Drivers: One, me.
5. Data Acquisition: On-board trip meter for miles driven. Reset every time. Actual gas pumped.

In both years, my driving situations were the same. Nothing out of the ordinary.

In 2010, I used 93 octane fuel exclusively for the 9264.9 miles driven which consumed 519.6 gallons yielding 17.83 mpg.

In 2011, I used 87 octane fuel exclusively for the 7854.1 miles driven which consumed 438.1 gallons yielding 17.93 mpg.

Statistically, I think the mpg for both fuel types are the same. I thought at first, there was a butt-dyno advantage to 93 octane. Perhaps, but I cannot prove it.

Some people think that burning 93 octane is less polluting than 87 octane. Not true. The simple truth of it is that my 4.0 was unable to tune itself to wring more mpg from 93 octane.

 

[JNR]

^^^fwiw, they recommend running 87 for smog checks, as apparently it burns more completely...

really, the only thing higher octane does is resist detonation more and if your 'tune' or engine, etc. is not designed for it, or takes advantage of this, then you're just wasting $$$.