Yep, it's all a question of load. If the engine is doing more work than it needs to (e.g., 3,000 RPM on a flat highway), it's not going to be as fuel efficient as if it were doing 2,500 RPM at the same speed and load. This is why I wish I had a 6-speed with that nice long top gear.

 

mixed city and highway, i love to tear up cloverleafs and whatnot, I can get 450 to a tank if i'm concious about it. Just got 360 with the A/C on more than half the time. 178,000mi on the odo. If you're getting anything less than 300/tank you either drive like an asshat, or your KS needs replacing(or /something!/), IMO....

speaking of 6th gear, anyone know if we have a 6sp option even available?

 

im sick of it. for last week i was driving slow, didnt pass 2500 rpm and still cant go over 300miles per tank

 

What if your car runs absolutely great? LIke, 60 ft times in the low 2's, 0-60 times in the mid 6's, passes other speedy cars like they were standing still even with the A/C on high -- but, your gas mileage in the city is 18 mpg at best (when 21 mpg is the factory spec)?

Would you mod your car to improve gas mileage by maybe 3mpg at the expense of "possibly" losing what is your best performance, to date?

That is my situation. I admit that I do not drive as slow as a Granny in a Lincoln Town Car, but I also do not drive as fast and wide-open like Mario Andretti either.

I have tried using all of the driving tips known to man, and replacing or cleaning all sensors, valves and injectors, but my best mileage in town has never exceeded 19.5 mpg.

On the other hand, the car runs like a top with no trouble codes anywhere (KNOCK ON WOOD, FINGERS CROSSED).

Do you follow the policy of "If it ain't broke, don't fix it," or mod the living daylights out of it until you have maxed out the mpg??

And, if you decide to do all the mods you can, will those costs far outweigh the extra you pay at the pump?

For example: let's say you gain a 3mpg (21 - 18 =3) increase, but the mods you did to achieve them cost $1,135. How long would you need to drive before you break even?

If you filled your tank every week, it would take 3 years to break even.

On the other hand, if you plan on keeping your car more than three years, then you would be getting a net savings with every fill-up...assuming that you continue to keep your car at its peak performance, which will not be without its costs as well.

Burning more gas than what is expected for my ride bugs me at more than just the cost level. I bristle at the thought of how much gas has been gobbled up by all the SUV's on the road for all the years they have been on the market -- one of the factors cited by economists as the cause of higher gas prices today.

However, if my mileage is around 18 in the city, then I don't have much reason to complain, now, do I?

Then, there is the "socially responsible citizen" part of me that makes me think about how much better the environment would be if I contributed less pollution to it by driving less and running more efficiently.

I'd drive a hybrid, if I could afford it. Well, maybe not.

Bottom line: what actually makes me feel better than the thought of saving the environment is the daily rush I get from punching the gas pedal.

Like all addictions, there is a price to pay!

 

in a city/highway the most i've gotten is 325 a tank, but still had at least another gal to go..so probably 340, 345, but i wanted to play it safe

 

I don't know what you are crying about. I get between 500 and 555 miles to a tank on the highway and have exceeded 550 about 3 times, albeit down to fumes. So the best highway MPG I've had is about 31. However, I consistently only get about 19 MPG in the city and that is with no air conditioning on. I suspect there is nothing wrong with your city mileage. I think the sticker city mileage is high.

 

thats pretty bad... I always get over 400 miles per tank easily. somethings wrong with your car, cause thats only like 17miles/gallon.

 

ive checked my ecu codes. its clear. i dont know wtf is wrong with it. maybe i should clean some valves or somethink??

 

new o2 sensors + knock sensor? clean tb, check for fuel leaks?

 

I agree with you about the sticker value. I'm also glad to know that you get around the same as mine.

Thanks! I feel a whole lot better!

 

And my car runs perfectly. It doesn't hurt to add a little extra air to your tires, which will improve fuel economy, handling and tread wear, perhaps at the expense of a stiffer ride.

 

I'm running 36psi all around.

 

Knock sensor is usually the cause of bad gas mileage. Could possibly be fuel leak or maybe a new fuel filter.

 

those chrome shoes ur car is on might have something to do with that horrible gas mileage...

also why not just reset ur car's ECU??

with me i'm getting 18.26 mpg....but thats because i take very short trips with a passenger, airconditioning,spare tire,18s,and a 40 lb set of coilovers in my trunk.

oh and my tires have 52 psi all around...very noisy and bumpy...but my radio takes car of that.

 

there is no fuel leak, replaced my fuel filter last year. is it time for knock sensor??

 

A bad knock sensor does NOT usually cause bad gas mileage, you will just lose a little power up top since the engine will not be able to advance timing so much.

One or more bad oxygen sensors WILL cause bad gas mileage because the engine will run rich and waste gas and reduce power.

 

On long trips I can consistently get 30mpg. I was getting 26mpg with 50/50 highway/city driving, but dropped about 2mpg after swapping the original steel wheels with new alloys (still get the great highway mileage though). Turns out that many of you knew this would happen.

Maybe it's my driving habits, but I'm really surprised at the low reported mileage. Some of you are barely cracking the 20mpg barrier.

 

What year Maxima and how many miles? Automatic or 5-speed? That's pretty decent mileage and is about what I get.

I suspect the new wheels are heavier than what you had before, which could explain the lower MPG in the city now.

 

'96 Automatic....I've heard a couple theories including the extra weight (I haven't actually weighed them yet, but between the wheels and wider tires, I'll bet you're right); and the weight distribution of the wheel itself (more weight on the wheel circumference).

 

HMMM Does anyone think that taking out the spare in my trunk would do me any good in terms of gas milage. Because that stock alloy is pretty heavy.

 

i get around 300 but my car is completely stock right now

 

taking out the spare might give you 5 - 10 miles more on a tank, but who wants to have to take out the spare in order to increase gas mileage, but decrease peace of mind?

 

27mpg with about 70/30 hwy/cty driving. 99 auto SE.

 

I go 560kms per tank (fills to about 60 liters). I am also using Fuel Power (FP).

 

Just got 29.4 mpg on a trip--not bad for a 7 1/2 yr old car. 110k, 5-spd, 72 mph cruise control all the way, cleaned and reoiled K&N. It's been a long time since I've been north of 26-27.

 

So is that an SE or GXE? Do you have a spoiler? Were you on flat land or hilly? Do you have mud guards?

 

SE, no mud guards.

The trip was Phila burbs (picked up the g/f) to Jersey City, NJ, and back. About 235 miles--key is the car didn't really touch any stop/go driving between fill-ups--only highway. Someone can correct me if I'm wrong, I think it's more uphill on the trip up, and reversed on the way back. If I split the trip in 1/2 I get better mileage coming back.

 

I generally get 22-25 mpg driving 70% highway, but I shift gears at 3500rpm or so most of the time. I could probably get this incredible gas mileage that everyone on here is bragging about if I started shifting at 2500rpms or so. And I recently hit 90K miles and replaced the ngk plugs, fuel filter, air filter, tb clean, coolant flush, pcv valve ect. and it did...........absolutely nothing for my gas mileage....maybe 1/2 mpg better if that. I think driving habits are much more to blame for bad gas mileage.

 

That's bull. Everyone on these board that has a 5spd gets worse gas mileage than autos unless they drive like grandmas..

 

330miles/tank thats it no more

 

See I think that's the thing: People with 5speeds, at least members of this forum with 5-speeds by choice, probably got them because they like to drive and they like the authority that a 5-speed gives you over your car and its performance. They're less inclined to drive in a take-it-easy manner than are others. So they get worse mileage even than an auto. From what I've read on this forum, though, those that do take it easy or drive like a grandma with a 5-speed (that's like an oxymoron, isn't it?) get the best mileage.

 

That's partly true. There's much less wasted energy in a clutch than in a torque converter. I think the 5-speed eats up 15% of the engine's power and the auto eats up 21% or so, so it's significant. However, the gearing of 5th gear isn't great for the highway, and I think that cancels out the efficiency of the manual transmission. Nissan's EPA numbers for the 4th gen bear this out: 21 city/28 highway (automatic), 22 city/27 highway (manual). Don't forget that the EPA test for highway mileage is not strictly highway, so if you're just cruising on the interstate you should see better than the EPA highway MPG.

 

How many 5 speeds have broken 500 miles on 1 tank? I did it in my auto going to Maxus.

 

500 miles in 1 tank... what the hell were you smoking that day?

 

I usually get about 280 per tank highway and about 150 local.

 

I got 513 on 16 gallons

 

Wow. I know this is the internet, but there have to be some standards, can we just say whatever we want and be blatantly wrong like that? 5spds get worse mileage if one is not a grandparent? You know the expression, don't quit your day job just yet....

 

 

Wow I barely get 450KM per tank (yes i'm from Toronto lol) so that's about 281miles per tank...

Ever since adding my Y/B/High flow cat/exhaust.. i'm getting around 600KM/tank (375 miles/tank) for you U.S. guys

 

Got 330 miles so far with 1/8 tank left right now, couple of WOT and brief 120MPH blasts though