I drove from Atlanta to Tampa last weekend and got 29 mpg the whole way. I started at 37 and it slowly went down to 29mpg. I kinda cheat though...anytime im going down a hill I shift into neutral and let her coast for a few miles. Also when i need to slow down...instead of hitting the brakes I shift into neutral and let her coast and slow down.

 

would a k&n filter help?

 

Hehe....funny.

Drive it at 90 MPH and then report back.

 

Proly not. More air/more gas.

 

That is not cheating -- just good economic sense.

But I hope you have a 6-speed MT. You should not do that in a Auto Trannie vehicle -- you will pay much more when your trannie needs repair because it did not get proper lubrication from running at highway speeds (or any speed) in neutral.

 

That is not cheating -- just good economic sense.

But I hope you have a 6-speed MT. You should not do that in a Auto Trannie vehicle -- you will pay much more when your trannie needs repair because it did not get proper lubrication from running at highway speeds (or any speed) in neutral.

 

This is the first I've ever heard that. Not that I doubt it, but on what do you base this assertion and can any mechanics or engineers out there verify this?

I've been coasting in neutral regularly at specific downhill locations for years and have never had any transmission problems. On the other hand, I usually am "out of" a vehicle in <50K miles.

 

Just got 28.5mpg on a 500 mile trip. Averaged around 75mph, with a few bursts up to 100 for fun

 

Just read the owners manual where there is discussion about towing an auto trannie with the drive wheels on the pavement -- don't do it. What you are doing is the same thing -- but for a shorter distance. You have been lucky so far, and the trannie has not failed on you. But you reduce the trannie life doing this -- those who get your vehicle used have paid the price in your previous vehicles.

I'm a Mechanical Engineer (but not an Auto Engineer). But it does not take an engineer to tell you this fact. Go to this thread on coasting with a 6-speed MT for my discussion of coasting with an auto-trannie in Post #11

http://forums.maxima.org/showthread.php?t=522817

 

If the engine's running you can do it! That way the transmission fluid pump will be supplying lubrication to the bearings, etc. However, if the engine is off you would be foolish to tow an auto with the drive wheels turning.

 

Just another reason why I have a manual trannie.

I still maintain that the lubrication from an idling engine running the trannie fluid pump will not be sufficient to provide adequate lubrication to the remainder of the trannie which is turning much faster. But it's your call, if you think that the idling engine will be sufficient. If it were my car, I would not do any coasting with an auto-trannie.

The slight savings in gasoline from coasting is not worth the potential cost of a trannie repair.

 

Just had a tank at 27.2 here.
Mixed driving mostly interstate

 

I get about 15 mpg in the city. Well thats according to the computer. I think it tends to overestimate the usage. I think in reality when I measure the amount of gas used and miles its closer to 19 or so.

 

WELL DAYUM YA'LLS GAS MILEAGE IS LOW.. IN THE CITY I GET LIKE 21-23 ON THE HIGHWAY I GET AROUND 29.. BUT WHAT WAS FUNNY WAS THAT I WENT TO MISSISSIPPI AND I GOT LIKE 31.2 MTG.. THAT WAS LIKE AMAZING.. AND IT STAYED UP THERE EVEN DRIVING THROUGH JACKSON.... MAYBE MY $H!T IS JUST TOP-NOTCH... LOL

 

Hey Ricky Bobby, you're drafting too close to those 18 wheelers.

 

I get about 28 in the city, and 450+/- on a full tank...

 

Yeah I get about 17.5 on hwy. It really sucks. lol

 

LOL THAT MIGHT BE.. BUT THOSE EIGHTEEN WHEELERS ARE JUST TOO CLOSE TO ME LOL!!
+ + + = MY MAXIMA

 

i get 16.2 highway/city. around 270miles give or take on a full tank

 

I drove a '93 Geo Prism (3 speed and 115 HP) for years and got 31-32 MPG overall, but I wouldn't go back to it. I just try and take it easy on the accelerator.

 

My 07 SE is averaging 20.7 mpg combined 50/50 city and highway. On the highway, it averages 28-29 mpg, and I use only 87 octane. Power seems unaffected, but no dyno runs or time slips to substantiate that. tommyturbo2

 

Well I believe you can trust the on board computer for a fair estimate. My commute to work is pretty short, which = bad mileage. It doesn't help that they've recently redone the roads and there's a lot of nice smooth curves for me to zoom through....

My usual mileage is 20-22mpg, but on highway trips it still jumps right up to 25-28mpg even though it's a 2004 and I haven't done anything tune-up wise except keep the air filter clean.

 

If you truly have a turbo on your Max, you should be using the highest octane you can buy. But if not, 87 should work out just fine for you -- it does for me when I leave the mountains of Colorado. At this elevation (6 K feet), I'm burning 85 octane with no problems. Nissan engineers have it all worked out so that 87 works fine -- but I would not use it for racing or frequent WOT demands.

 

Hey Silvermax, a question for you. My wife will soon be picking up a Frontier w/VQ40, which will of course be recommended for 91 octane. The CS where we gas up offers 87, 88, 89, 90 and 93. The 89 and 93 have ethanol stickers on the pump, though I am told that only the 87 is completely free of ethanol.

My question is this, as my wife is incredibly tight(cheap!). If she alternates between 89(which is 20-25 cents cheaper than 93) and 93, will that give her approximately an effective octane of 91, or does it not work that way?

I am not a huge fan of ethanol, but living in the middle of corn country, it's hard to avoid it.

Thanks, Mike

 

tell her to just go w/ the 93 unless she wnts problems later in hte cars life... that should freak her out enough to spend the xtra 20 cents a gallon...

Or tell her higher octane will give u better gas mpg whcih inturn will save money

 

Given that you are in Iowa, I suspect that the 89 octane is 87 octane blended with 10% ethanol -- and the 88 octane just has 5% ethanol added. Given all of the options this station offers, I suspect they are actually blending the ethanol into the gasoline at the station. (Ethanol does not travel well in pipelines and is usually blended into tank trucks at the terminal.) Do they have what appear to be blending pumps? If they started with an ethanol free 90 octane gasoline and blended 10% ethanol into it that should give you about 93 octane.

Given that you are in Iowa, the 89 octane should be cheaper than the 87 octane -- because Iowa waives some of the state taxes to make it so.

It does not work that way. But you can fill up half the tank with 89 octane and the other half with 93 octane and get about an average of 91 octane.

Do you know the compression ratio of the VQ40 engine? The older VQ3.5 had 10.0 to 1, but starting in about 2003 the compression ratio in the 3.5 was raised to 10.3 to 1. Also, does the owners manual for that vehicle say that it is accpetable to burn regular gasoline? You need to know the answer to at least one of these questions to be certain that a lower octane will perform properly in this vehicle.

To get the most economic option for your wife (and to convince her that is the case) you should provide me with the octane and current prices of different grades you are considering using. It is possible to blend different grades in you tank to get an approximate average octane. When I have this info, I can make a better recommendation.

Neither am I, but I do buy it when the price is right (cut vs gasoline without ethanol).

A number of posters on this site say that if you don't burn only premium gasoline all of the time, you will have future problems with your engine. While this is their opinion, none have offered difinitive proof that this will happen burning other than premium. I'm still waiting to see the proof. A while back I communicated with SteVTEC and he convinced me that on the highway, you are likely to get better gasoline mileage burning regular than burning premium. No proof here, either, but I tend to believe this is the case. And that at least the mileage with the regular will not be worse than with the premium.

 

SilverMax,

Thanks for your response. Not sure about compression ratio, but suspect it may even be a little higher than VQ35, as they get the added displacement by increasing the stroke. I will check OM for both CR and fuel recommendation when we pick up truck, probably this weekend.

I doubt they are blending it on site, as it's a run-of-the-mill convenience store and pumps look pretty typical. On a typical day, price range would be as follows:

87 - $2.95
88 - $2.98
89 - $2.85
90 - $3.03
93 - $3.05

Will check back on Monday.

 

As I suspected, the state of Iowa is giving them a tax break for the 10% ethanol blended into the 89 octane gasoline -- it has the lowest price. You should be happy that your overall prices are this low. I'm paying your 93 octane price for 85 octane regular here in Colorado. And most stations here have 85 at prices up to 3.299 per gallon.

Boy, it's hard to justify paying 17 cents more per gallon for one octane difference (90 vs 89). I suspect that the 90 may well be ethanol-free at that price difference.

But I also suspect they are blending 10% ethanol into the 90 to get 93 octane premium. It's possible that Iowa only gives a tax break on one grade of gasoline, and they choose the 89 octane because it gets them more overall volume in their store.

Assuming your owners manual recommends premium for maximum performance, but allows regular for less than maximum, I would be buying straight 89 octane ethanol blended gasoline. Your mileage will suffer slightly due to the ethanol, but you will have more than 87 octane and at the lowest price of any grade. If you want to stay away from ethanol in the gasoline, you should pay the 17 cents more and buy the 90 octane.

If you want to feed this vehicle only 91 octane gasoline, I would then tank-blend the 90 and 93 with 2 gallons of 90 to every 1 gallon of 93 you put in your tank. If you have a 20 gallon tank that is half full (by the gauge), you could first buy 3 gallons of 93 octane and then buy 6 gallons of 90 octane.

Let me know what the owners manual says about gasoline recommendations when you get the vehicle.

 

06 SE
23-24 city
29 - hwy ....if I drive the legal limit of 70-75.

 

SilverMax,

Still can't find compression ratio. Owner's manual gives essentially same info as our Max's - premium recommended, if not available 87 can be used with decreased performance.

Mike

 

Try the Nissan web site. I know that it took me a while to locate this info and determine that in about 2003 Nissan had increased the compression ratio in the VQ3.5 from 10.0 to 1 up to 10.3 to 1. If I remember correctly, it was in some obscure place on their web site. Good Luck.

 

nissannews.com...

has full specs, including compression ratio, for all vehicles since 2004. Once at the home page, click "Nissan" in the gray band near top left. Then select a vehicle on the left. Once at the vehicle's page, select "specifications" on the right.

It appears that all 6G Max's have 10.3:1 CR, as does the new Altima w/ revised VQ35. The 2007 G35 sedan is 10.6:1, and the 2008 G37 coupe has 11.0:1.

Hope that helps!

 

Reset the trip-ometer when you fill up. The next time you fill up, take the #miles / the gas amount = true MPG.
I can reset the computer and do occational readings and can come out with readings like yours (sometimes I can get way over 30MPG on the highway). But at the fill up times, my calculations show between 19-19.5MPG. This is about 50city/50Mwy.

 

When I compare the manually calculated gas mileage vs the computer generated gas mileage -- they are always very close -- less than 1.5 MPG difference.

But when I average both the manual and the computer mileages over a longer trip with 5 or more fill-ups, they are even closer. I take this to be the inability to exactly fill your gas tank to the same level every time you do a fill-up. If you do a short-fill, you get a better mileage than if you do a long-fill. But when you average the manual calculations over 5 or more fill-ups, this problem gets averaged together and compares very will with the average of the computer generated results over the same miles.

At least this has been my experience with my 04.

Final point -- whenever I'm driving on the interstate and have a good tail wind, I will get over 30 MPG -- otherwise it runs about 27-28 MPG when driving around 75 MPH. And the mileage is about 2 MPG worse if I'm fighting a head-wind.

 

Thanks to jcalabria above! Great resource!

C/R for VQ40 is 9.7 to 1.

 

i get a fairly consistant 24 mpg with mostly highway driving.

 

You should have no problem burning only regular. Honda has 10.0 to 1 in their V-6 Accord and only recommend regular.

 

22.5 Mpg ( Mainly Hwy)

2007 Max

Not What I Expected, But Better Than Most.

Wj

 

thats pretty broad. ive noticed mpg (mostly highway) as high as 29 mpg and as low as 19. I think some of our feet are heavier then others

 

I have been floating right around 21 MPG mixed driving, also with using the AC on and off. I sit in alot of bumper to bumper traffic. Out here in NJ rte 80 is a nightmare to commute on.