Bad mileage problem

[JonathanPrem]

Hey guys. my gas millage is so garbage.

Its summer so your gas millage should increase. But in my R50 cant even get near 400 km city (my unlce 06 s430 does 300km half tank and it same size as mine but its a V8). I've done it all fuel filter,air filter,spark plugs,oil,trans oil and cleaned throttle body and MAF sensor. After all that all i get is 300-350 km/full tank all city. I drive my car like a granny since it eats my money like no tomorrow. I do have some problem but would they cause that much fuel. first is my torque converter doesn't lock at 100(or at all), my hub assembly is bent,so my wheel wobbles and i changed 5/6 plugs and broke one coil pack screw .

Can someone help me out. I now Qxx4 said hes get 300km for half tank on his 3.3L

[02pathy]

are u driving at least 16km from start to finish once u start ur car, ideally u should drive 16km none stop(not stop and go) to get the best gas mileage at minimum, i get around 300km to the quarter tank too but mine is all short trips not good for the truck or any gas vehicle, it bothers me too, i feel even with the 3.5 v6 its still a very underpowered vehicle

wobbling could create drag in a way, and that 6th plug might not b burning as good as the rest, can probably create an imbalance in ur engine

[W O T]

3.5 is underpowerred? Hell my car rips, I was impressed as hell with its power for its size, I beat on my buds integra ls for breakfast, side by side with my buds maxima 3.5L and friends mazdaspeed, torquey for sure to me, and Im no stranger to a race car

And 300km/ quarter tank? You only runnin on 2 cylinders lol?

For reference, my cars from florida so I dont know exactly, but I get about 240-260 miles to a tank. So like 400ish km/tank

Mind you I dont pussyfoot around, Im quite the heavyfooted driver, and maybe 1/4 of my miles are from highway.

3.3 gas mileage will be ALOT different than the 3.5

No check engine lights? First thing Id try is to reset my ecu, pull that neg cable off for a couple hours

[02pathy]

yeah wot, my gas mileage is about the same as ur roughly, don't get me wrong i am not putting down the truck, i know it has power but u gotta really mash on the gas, i just mean it has a slow start if u have a light foot whereas some v8 cars go like hell at even the slightest of touch, maybe its just me, i don't no

i am just not sure if the power to weight ratio was met properly

[W O T]

Go drive an Escape, Jeep, Sante Fe, Pilot, Trailblazer. Then come back happy to the vq35de lol

My family has owned all those in the last 4 years, they sucked

[Qxxx4]

how are your O2 sensors? pulling any codes for them?

Here are the records from my last few fillups. Its a quick and easy calculation and lets me know exactly when bad gas mileage starts. At fill-up i set my trip meter to 0, then on my next fillup write that number down on the receipt, and reset the trip meter.

(Litres used / km's driven) x 100km

To convert from L/100km to MPG go herehttp://www.convertworld.com/en....html

The factory spec for gas mileage for my 3.3L is 15 MPG city / 19 MPG hwyor 15.7L/100km city / 12.4L/100km highway

Shell V-Power added for this trip11.7L/100km, 20.1MPG - 340km highway (one trip), 149km city, 61.245L consumed

Back to regular shell 8712.7L/100km, 18.5MPG - 340km highway (one trip), 142km city, 58.677L consumed

18.4L/100km, 12.3MPG - 263km city, excessive idling (troubleshooting weird noise from new wheels. many short trips) Also raced an impala....uhmm yeah. Lets not count this one that was my first week with the new rims, real aggressive!

First trip with new wheels (odometer only affected by 2.4%)11.6L/100km, 20.3MPG - 340km highway (one trip), 155km city, 57.638L consumed

Trip home...heavy winds, 2 areas of construction on 401 (reduced speed)14.0L/100km, 16.8MPG - 340km highway (one trip), 66km city, 56.977L consumed

On average if i do all city i get about 14-16L/100km

My next trip I will have my cargo cover removed (good 30lbs). The new wheels dont affect gas mileage at all on the highway but they may affect city with all the accelerating, time will tell, im driving carefully now to find out. Weight is a huge factor, yet I have my subs, rollerblades, and either my toolbox or my luggage in there at anytime, but those are necessities.

Dont think because your engine is bigger and more powerful it should be a pig on gas. The 3.5 gets close to if not the SAME gas mileage as the 3.3. My dads 4.0L V6 Frontier gets even better mileage. its just a more powerful, more efficient, NEWER engine.

hope i didnt bore you guys

[JonathanPrem]

I had a O2 senor and got it replaced and flashed threw nissan. If i flashed my system do i still have to reset the ECU?

one more thing after changing my spark plugs my car rpm seem to gonna up a tiny bit 200+rpm more.

[K03sport]

I had a O2 senor and got it replaced and flashed threw nissan. If i flashed my system do i still have to reset the ECU?

one more thing after changing my spark plugs my car rpm seem to gonna up a tiny bit 200+rpm more.

200rpm is not a tiny bit. That is almost a 30% increase.

Flashing the ECU is essentially reprogramming it, so I'm not sure what you mean when you say you have to "reset" it. Are you talking about resetting your throttle body, or are talking about actually removing power from the ECU so it "resets" like erasing codes?

Mileage in the PF is not great. Ours gets about 250miles (400km) before refilling in the city. At half tank, we are around 130-140miles (200km). The gas gauge is not 100% accurate, it is only an appoximation.

The tansition from winter to summer gas might take a while. I guess you could run a bottle of fuel injector cleaner through one tank. Yes, you will see lower mileage while you do that, but tanks after that "should" see an improvement.

The only advice I can give to help improve overall mileage is make sure your tires have enought air in them (32-34psi), and use the gas pedal the least amount possible. When approaching a stop or red light, let of the gas and use the PF's momentum to carry you to the stopping point. You will notice that the PF will coast a ways before it starts to slow down to speeds that will annoy others around you. If you are the only person around, you can begin your "coasting" sooner. Don't throttle up to the stop and hit the brakes hard at the last minute. This just uses more gas.

Stop and go driving isn't the best place to see stellare mileage. A spark plug change might make a 1-2% change, but nothing huge.

As far as the 3.5VQ being underpowered...actually, it is in the PF. The V6 has to work harder to move the PF than a V8 in something similar. Example, The VW T'reg V8 got better "EPA" milage rating than the V6. The V8 is able to supply more TQ so it doesn't have to work as hard as the V6 does to get the same mass moving. However, sitting idle doing 0mph, the V8 will eat more gas than the V6, but both engines are still doing nothing.

You can also try putting synthetic fluids in the trans and diffs to reduce friction as much as possible. Same for the oil. Your only other option is to put your PF on a diet and help it lose some pounds.

Other than this, I have nothing. Good luck.

[JonathanPrem]

I did all the things K03sport. But if i remove the negative side of the battery for a hour. What kind of changes am i looking at for fuel and im also running STP fuel injector clean in my ride right now. Hopefully fixing the trans will restore my gas.

Edit-Would Fan belts make any difference. I never changed mine yet and its 180km.
Modified by JonathanPrem at 1:56 PM 4/15/2009

[Adnan]

i get about 150 km half tank,never got the chance to calculate full tank cause my cluster freezes

my most intriguing moment was when i drove to niagara falls last summer with a full tank, after traffic on the QEW,and tons of time spent searching for parking at the falls+ getting lost,i came home with 1/2 tank left and the odo was reading 150-160 km

[K03sport]

What kind of changes am i looking at for fuel and im also running STP fuel injector clean in my ride right now. Hopefully fixing the trans will restore my gas.

Edit-Would Fan belts make any difference. I never changed mine yet and its 180km.

You are only supposed to run one bottle of cleaner through a tank every so often. I think every 15,000 miles is plenty. With detergents in gasoline, injectors don't get clogged as much as they used to, but then again, the quality of the gasoline will affect this.

How often do you do an Italian tune up? Yes, those will eat up more gas, but really get them pistions moving. Wait for the engine to get up to operation temp before performing said tune up.

As far as the belts go, they won't improve mileage, but letting belts go too long could put you in another world of hurt if they break. I think belts should be changed every 6-8 years or about 60,000 miles, but Nissan may have another schedule.

There are several reset procedures out there for the throttle body, TPS, and one other thing. Search the Z forum or the VQ forum for those reset procedures.

How's you air filter?

[JonathanPrem]

Whats the Italian tune up . Ill check up the reset for throttle body since i did clean it out.

[Buzzman]

My '02 gets about 350 Kms to a tank, and that's mostly city driving. I average about 15L/100Kms.That's pretty normal for these things, whether it's a 3.3 or a 3.5.Don't expect much more than that.One thing you mentioned was the transmission doesn't go into overdrive. That will eat gas big time.What are you reving at when going 100 Kms/hr? Should be less than 2,500 rpm's.As for power, I think it's plenty enough.I can beat a lot of cars off the line with my Pathy. It's no slouch. Fix your little problems and you should be fine.

[K03sport]

Whats the Italian tune up . Ill check up the reset for throttle body since i did clean it out.

An Italian tune up is taking the truck out and mashing the gas to the floor, repeatedly.

This stems from the ole carbureted Ferrari (and other Italian makes) days when owners would baby their cars because they didn't want to damage them. They would take the car to the mechanic saying it wouldn't run right. The mechanic would proceed to take it on a test ride and beat the ever-living piss out of the car, clearing out the "junk". When it was all said and done, the car purred like a kitten. That is an Italian tune up.

&#9608&#9608&#9608 Excellente!

[pathfinder9035]

Hey man, i have a 5 speed 3.5 liter pathy. I constanly get about 220-250 a tank depending how how good of a driver i am..lol. on the highway though i have seen near 400 miles to a tank.

what do u expect from an suv though. I always average 14-16 just driving around and 18-20 on the highway. My o2 sensors are bad so i could see an increase when i repair those. I use to average about 17 all the time but that was before i added bigger tires and my o2 sensors were perfect then.

here are somethings u could do.

replace all fluids to reduce friciton like transmission lube diff lube.

repack your bearing or check your bearing. Make sure your driveshaft u joints have proper amount lube in it.

check your brakes.

Check alignment and balance

Get a compression check done to make sure all cylinders are working properly.

U can always buy a manual hub that will disconnect the front cv axles and that will really reduce drag and u can see improvements buy up to 2 mpg. You could reduce your tire size and that will also increase gass mileage...but why would u do that...so forget about that idea..:p

go on ebay and buy one of thos vortex generators that u install in the intake. i had one for my Toyota 4runner and i actually did see alittle improvement. about 20-30 miles a tank extra.

Another thing u can use is buy a bottle of lucus gas treatment. Its 10 bucks and it will treat up to 100 gallons so 5 refills. Its suppose to boost your gas mileage up to 2 mpg when added to the tank after refills.

good luck.

[Adnan]

go on ebay and buy one of thos vortex generators that u install in the intake. i had one for my Toyota 4runner and i actually did see alittle improvement. about 20-30 miles a tank extra.

Whoa! they actually work?

[Qxxx4]

Whoa! they actually work?

until they blow into chunks and are sucked into your intake, leaving your engine to combust metal fragments

[K03sport]

Just filled up the beast...197.7 miles on the trip meter. 16.1 gallons later (12.2mpg). Granted, the PF is a short trip mobile. It gets driven on many short trips and never really get up to operating temp.

It has been in the 30s in the mornings a lot this month and the PF does not like cold weather. So, short trips and several minutes warming up kills the mpg. An oil change will be coming up soon, just due to the short trips and the fact that 3,000 miles takes about 9-10 months.

Plain and simple...if you want better mileage, drive long distances and don't stop often

[pathfinder9035]

yeah i guess it seem like it worked. i am buying one for the path. i will keep you guys updated to see if it works on the path.

[W O T]

They "worked" cause you probably were just easier on the gas while seeing what kinda gas mileage improvement you got, you were the improvement

Right foot is everything

[humsafar77]

Bad Mileage Problem here as well.

My 2003 pathy gives 300Km in Full tank, out of which 20-30 Km is Desert Drive,

but still it is too much, It should give atleast 350 Kms with approx 30 Kms of Desert drive.

My friends Nissan Patrol 4.5 L engine gives around 300-325 Km in same quantity of Fuel.

I wonder what is wrong. I regularly clear my Air filter after every trip from Desert, the Plugs are also clean.