im starting this thread to figure out what I can put on my car..or take off *if necessary* to get the best gas milage out of it...my car is completely stock and i would just like to know what i would need to buy (O2 sensors? knock sensor? intake?) and still get a modest performance and better gas milage. Thanks in advance.

 

How many miles on your car? When did it last have new spark plugs, fuel filter, air filter and an oil change? What tire pressure do you run at? What kind of fuel/octane do you use? What is your present mpg -city, highway, combined?

A K&N panel air filter and synthetic oil might give you marginal gains.

Lastly, how fast do you drive and is your car an automatic or a 5-speed?

 

miles = 102,xxx
spark plugs = 94,xxx
fuel filter, air filter, and oil change = 100,xxx
pressure = about 33 i think
fuel = 87 (i should be using 89 but i dont get any difference)
gas milage per gallon (city/highway/combined) = a quarter of a tank is about 75 - 100 miles....a full tank = 300 - 350

1. I use synthetic oil now
2. I drive speed limit..except sometimes when i accelerate from a stop light...or im on the freeway doing like 80 or so and i have an automatic

 

So I take it you changed the plugs at 94K. A full tank providing only 300 to 350, combined, is pretty pathetic.

Have you ever used Chevron Techron to clean your fuel injectors and SeaFoam to clean your intake manifold? How is your throttle response and idle - have you ever cleaned your throttle body and idle air control valve (IACV)?

When was the last time you had your automatic transmission flushed or drained and filled? When was the last time you had your radiator flushed?

I suspect the majority of your problem can be attributed to running 87 octane gas and driving 80 or so on the freeway.

 

so what do you recommend i get done on my car...what should i get flushed..and what should i get changed?..i have a little $ to spend..and i rather spend it to make my car more reliable than buying a body kit or something...how much you think it should run me?...and what results should i see after? i dont know exactly the last time anyting was flushed on my car...i had a complete tune up and everything done by one of my brothers friends at 94,xxx...just let me know exactly everythng that should be done..and on my next paycheck..combined with this one..i will do everything..thanks.

 

Calculate your gas mileage correctly (miles driven divided by gallons used) and tell us what your MPG really is. You might be already getting good MPG, thus keep driving the car just as it is.

You cannot measure MPG by your gas gauge, look at the fuel pump when you fill up to see what your actual gallons of consumption was for the miles driven, then do some math and get your MPG.

 

He has already said that all he gets is 300 to 350 miles to a tank in combined driving. Assuming he doesn't fill the tank up at 1/4, but takes it down to E when he makes that statement, anyway you slice it his fuel economy isn't good. But follow njmaxseltd's suggestion and get back to us with an accurate assessment of your mpg.

It could be that city driving means being in gridlock for extended periods and that wreaks havoc on your fuel economy.

I know gas is expensive in California, relative to some other states, but don't be afraid to go up to at least 89 octane and preferably 91 octane.

 

what would be good gas mileage for his car? and does auto vs. man make a difference? how so?

 

i still want my question answered about everything that i should get flushed and changed for a complete tune-up..im gonna fill up my tank today...and restart my trip counter today..ill note how many gallons i put in...and how much i ltravel for every 1/4 of a mile..i wont run it too hard..and ill get back to you with an ACCURATE count..but still post everythign that needs to be changed/ or flushed to benefit my gas milage..THANKS for the help

 

I don't use my car for commuting anymore, but when I drove it 11 miles each way in downtown rush hour traffic, I used to average about 20/21 mpg. Straight highway driving at 70/75 mph, using a lot of cruise control and no a/c, I can get a minimum of 27mpg and have had as high as 31 three or four times.

 

You still don't get it. Forget about 2 things: how much you just put in is absolutely irrelevant, and guesstimating mileage on 1/4 tank increments is equally as irrelevant. What is relevant is topping the tank up now, setting the trip odometer, driving the car until its almost empty and filling it right back to where you filled it up before. Then take that mileage and divide by the gallons you just put in - that is your mpg. Reset your trip odometer again and do the same thing again. Mileage varies depending on the nature of the driving, traffic patterns etc. After say 5 tanks of gas, you should have a fairly good assessment of what your actual mpg is.

How long have you owned this car? How many miles have you put on it?

How the hell are we to know whether you should flush anything if you don't know when it was last done? We aren't mind readers.

Forget about the transmission for the time being. Go to a radiator shop and tell them you want a pH test of the radiator coolant. Based on the color of the paper strip they insert into the rad, they can tell you if you need to flush the radiator. It should be done every 30K or 2 years. If you don't drive 15K a year, you maybe able to get by with longer intervals, but still get it done at 30K.

 

I would say that not much you do to our Maximas will increase the gas mileage much more than marginal.
I mean, the tapped out the potential at the factory and you will not get much better than that.

I am getting like 25mpg in town, with an aftermarket y and 5spd.
I do have a cylinder misfire, but the mileage was the same before.
It just doesn't change much, unless you have a really bad knock sensor.

You will get a little better mileage with the premium probably.

 

lol..ok i what i mean by flushing/changing....just lets say nothing has ever been done before...no change in spark plugs or anything...LETS just say every is original..i mean..the car probably wont be driveable if it was..but thats why this is a scenario...what would you do?..like what would you go about changin and flushing?..and dont say everything..i mean specific...because im gonan check everything and make sure its all good..just i dont know where to go about what to start from...and what to end at. Thx

 

huh?

10char

 

Read the stickies, the FAQs and buy a Haynes manual. Report back in 7 days time. Until such time, stop asking inane questions and please educate yourself!

 

like rmurdoch said....Check the stickies... or your owners manual... or a hayes...... or go to your local mechanic..... they all will tell you what needs to be done for your car to run properly


Knowing is half the battle!!!!!! GI-Joe!!!!

 

uh put in 93 octane ull get better gas milage... although 300-340 aint that bad... thats what i get

 

lol..ok..thx for your help. Im a newb what can i say?

 

About 350 would be normal, and putting in anything higher than 89 is a waste of money, yeh u get an extra 2 miles per gallon but u spend way more. I drive stick and still average 350 per tank! Just keep ur tires properly inflated and thats it. Maximas weren't made to be efficient, but rather fun.

 

Here, I'll tell you how you can get good gas mielage. Use a light foot on the accelerator. Try not to push it past 3k rpms. Try to not come to complete stops when possible and conserve your kinetic energy so that you're not always stopping and going but rather just slowing down and speeding up gradually.

Don't ever floor the gas pedal.

Check your air filter, if it's dirty, replace it. If your fuel filter needs replacing, replace it.

Make sure all your tires are inflated to the same pressure. (30-35psi should be fine).




I get about 100 miles before the tank gets to the full marker, 175 by 3/4 marker, 250 by 1/2 marker, 340 by 1/4 marker, and when I refill I'm approaching 410-420. I get around 26-27mpg... approximately half city and half highway miles. I'm 17, if I can be that easy on the accelerator, surely you can too, no matter what your age.

*ps* I use 85

 

93 octane to get better mileage, no way.....made no difference in my car or other peolpe I have talked to.....

 

Holy crap.....that's insane mileage....but then again, you live in Colorado. I'll be happy to get 200 by the halfway mark.

 

That's pathetic gas mileage. I've never had that low since I've owned my Maxima and I bought it brand new. But what do you expect when you live in NYC?

 

It's not that good, there have been gas mileage threads before with people who claim upwards of 30mpg (mostly highway though). Sorry, why are CO roads more suited for that type of mielage than Boston's? (just curious, never been to Boston before).

 

last time i got 365 miles for a full tank and i somewhat did have a heavy foot but it seems that when i drive normally i get like 350 miles to the tank so maybe my car likes it rough??

 

wow, way to beat a dead horse

 

I average 300 to 350 miles on a tank, given half city and half highway driving. Autos dont do well in the city so dont expect a high number as many of the ones posted with manuals. I think 18 in the city and 24 to 27 on the highway is expected of auto maximas provided it is maintained. Make sure the tires are inflated to 35 psi all around, when the car is COLD. Do not inflate the tires when the tires are warm because it will be INACCURATE.

Clean the Throtle Body, Inflate tires to 35, put in a bottle of fuel injector cleaner, and get two new front 02 sensors if you really want to go all out.

 

another question...does anyone top of their tank? or is that bad for the car?..i mean when the hose unclicks itself to say its full...do you push it one more time..to get just a little extra gas into your car?

 

You as questions like a newb but you've got 350+ posts to your name in two months. Do you take the time to read in between the times you are posting?

If topping off is bad for the car, then mine would have been a junker by now. You can go a little past the safety shut off on the pump but not by too much. Too much and you will overfill the tank and have fuel spilling onto the ground.

 

hey leave my nooby questions outta this..no point to criticize..i rather know everything that know something with questions unanswered.

 

I think his point was that you should use Google sometimes instead of just asking questions.

 

Not that anyone particularily cares, but I get 22-23 MPG city and 24-25 MPG highway. I cruise at 80 to 85 MPH most of the time. For some reason, I can't seem to break the 135 MPH barrier. I'm stock on the engine, except a Pace Racing CAI. Got 123,000 miles and going strong.

 

It's hard to believe that your highway mileage is nearly the same as your city mileage. I have never heard of that. My highway mileage is about 7 -11 mpg better than straight city commuting.

 

ok, change spark plugs to ngk coppers or platinums (coppers are cheaper, last 1/2 as long)

flush your tranny fluid ONLY if it's not varnished or doesnt have metal shavings in it.

Timing belt does not need to be replaced, maximas come with timing chains meant to last the life of the car.

Bleed the brakes if there's excessive play or mushiness in the pedal, and tighten the throttle cable for the same reason.

Check your lights to make sure they're functioning properly

Drain your radiator and refill with antifreeze, but mix it with 40%water.

Replace your windshield wiper fluid reservoir.

Check your ECU for ghost codes

Use 91 or better grade gasoline, you put less wear on your knock sensor, and you get better performance and gas mileage.

Do an oil change every 3k-3.5k, be sure to change filters.

Change your fuel filter.

Replace brake pads and resurface rotors.

 

thats why i would back this guy up in the middle of brooklyn at 12 a.m...if he needed it..THANK YOU FOR ANSWERING THE QUESTIONS!..by the way fred..ill call you tommorow to confirm that i recieved the package which i hope i did..peace

 

Stickys would have helped in the same way, but I would hope that most people here have prior car care experience, or would have bought a Haynes/Chilton manual beforehand rather than start a useless thread.

 

lol..i was in alot of threads were you commented today...wow you are really hatting today..lol..oh well...everyone has their opinions

 

I've only been on about 1/2 hour so far today (sunday)... It's not a matter of opinion, it's a matter of not being lazy and buying a manual isntead of getting a dozen different opinions and choosing one you're happy with.