Gas mileage?

Post by **Omar** » Mon Jun 09, 2003 5:49 am

First of all, how are you guys doing? I have been really busy lately. Anyhow, I am back.

If you remember I posted about how my J is slow and seems like I am losing power...well lol I dont know but it seems fine now. Maybe I think too much.

Anyways, I wanted to know your gas mileages. I use premium gas (I have no choice, but it kills my wallet) everytime. I can get about 180 miles in a 1/2 tank (with A/C). Now my question is...is this poor? normal? or good?

Anyhow, I am currently working on cleaning my J and fixing it (the bumper, remember?) I got pics, but they arent that great. However, if you guys still want to see them, let me know.

Take care.

Later...

Post by **j30t** » Mon Jun 09, 2003 5:49 am

180 with the A/C seems good to me. I average around 19-20 and i try not to use the A/C too much. I also drive like a dumbass so my mpg is lower than if my dad were to drive my car.

Post by **juiceman** » Mon Jun 09, 2003 5:49 am

Normal

The gas gage is not very accurate, I vary between 210 and 160 miles on a half tank but I only judge MPG based on fillup

I averarge in the 21's and I do not use air much. I do during the summer and get about 1 mpg less.

You may notice that when the light comes on the fillup takes less than 15 gallons of the tank's 19. I think it was determined previously that the sending unit for the tank gets some corrosion which increases the resistance thus the change in tank level. Plus Infiniti probably did not want their cars on the side of the road looking broken down because of a person who likes to push the limits and not fill upwhen they should.

Post by **steelvulture** » Mon Jun 09, 2003 5:49 am

Are these mileages city or highway or mix? I hope these are highway otherwise I need to figure out what's bogging down my J (other than my weight).

Post by **j30t** » Mon Jun 09, 2003 5:49 am

Mine are city...i used to get 18 until i added a can of BG44k then i got about 21.5 for two tanks now its down to 19.5 average.

Post by **Q45tech** » Mon Jun 09, 2003 5:49 am

Remember that oxygenated fuels produce less BTU so the mileage with them is always worse by 1-1.5-2 mpg.Usually the worst around town where your acceleration is asking for power production.

Post by **Q45tech** » Mon Jun 09, 2003 5:49 am

Remember that oxygenated fuels produce less BTU so the mileage with them is always worse by 1-1.5-2 mpg.Usually the worst around town where your acceleration is asking for power production.

However most of us in the South are not exposed to oxygenates.

Post by **juiceman** » Mon Jun 09, 2003 5:49 am

My driving is mixed, speeds of 30 mph, 40 mph and 50 mph I really do not do alot of hwy to even test it

Post by **RobHakari** » Mon Jun 09, 2003 5:49 am

when i get out on the highway i average between 19-21. but when i drive around my little podunk town i tend to get about 16 or 17 with a half tank

Post by **tando** » Mon Jun 09, 2003 5:49 am

There must be something seriously wrong with my car, because I usually get about 240 miles to a fill-up. I was going to order BG44K before, but maybe now its more urgent. I have a 93J with 101K miles. Any suggestions?

Post by **j30t** » Mon Jun 09, 2003 5:49 am

The BG44k has increased mine maybe 1.5-2 mpg over the past 6 fill ups. I dont know why you are only getting 240...mine usually can last until 360 before i fill up.

Post by **juiceman** » Mon Jun 09, 2003 5:49 am

do a search but I think this is how it goes

1. Throttle body cleaning see this site for how to http://www.twinturbo.net/ttnettech/tb/tb.html2. fuel inj/rail flushfuel filter change3. check for fuel leaks *** this is important as I think this is what is causing your problem. Look at all lines etc for damness and smell for fuel4. check timing5. good spark plugs (factory spec) do not substitute6. proper tire pressure7. good alignment

Post by **tando** » Mon Jun 09, 2003 5:49 am

Well, thinking about this problem, I just remembered something. Along the length of the driver side there is a plastic housing that was dragging one day when I was driving. I pulled over and put it back and didnt think much of it. I went to my mechanic and showed him and he said it was the cover for the fuel lines. Maybe I hit something and im losing fuel through there. I will promptly check this tomorrow as my girlfriend has my car.

Post by **PalmerWMD** » Mon Jun 09, 2003 5:49 am

In town hard/easy driving: 12/15 mpgHiway 90+in mountains/70 on even hiways : 16/22 MPG.

Fred..

Post by **springnr** » Mon Jun 09, 2003 5:49 am

97 J30 71k miles

19-21 in town23.5-25.5 Highway

The 25.5 was my last trip from Dallas to Houston and back. I waited till I was away from the metroplex to fillup with real gas instead of the smog gas we get in Dallas. Avg ~75mph

Post by **90Q45blue** » Mon Jun 09, 2003 5:49 am

Arrrrrrrgh, I think my car is getting like -2mpg right now

Time to clean the TB, IAC, EGR, etc etc

Nick

Post by **valleybouy** » Mon Jun 09, 2003 5:49 am

Recent 1400 mile road trip in our 91q with 74k produced 21.5 mpg average. 4 adults and luggage. The Northwest states apparently have good gasoline. My michelin xgtv tires have 11k miles and show even wear but are starting to get a bit noisy. valleybouy

Post by **suk my j, 30** » Mon Jun 09, 2003 5:49 am

180 till half is good I hardly get 150 till 1/2 and I just gave the car a tuneup with 4+ spark plugs and a K&N filter

Post by **VimyJ** » Mon Jun 09, 2003 5:49 am

I get about 350 miles from a tank.

Post by **PalmerWMD** » Mon Jun 09, 2003 5:49 am

suk my j, 30 wrote:180 till half is good I hardly get 150 till 1/2 and I just gave the car a tuneup with 4+ spark plugs and a K&N filter

You mean Boschplat+4?

Their are a known poor fit with our cars here and may be in part responsible for your mailge issue.

Other common causes are dirty Throttle body, old Oxygen sensors, dirty injectors poor MAF/MAF connector.

Is you K&N underhood old cold air intake?

If the former than that is also a common source of low mpg(+low power)

Fred..

Post by **suk my j, 30** » Mon Jun 09, 2003 5:49 am

Yeah but I'm not going to buy new injectors and I don't believe in those cleaners so what do I do?

I have another problem, my passenger door won't open the lock keeps getting stuck. Every time I open the lock it makes a noise and still won't open

Post by **AZhitman** » Mon Jun 09, 2003 5:49 am

suk my j, 30 wrote:Yeah but I'm not going to buy new injectors and I don't believe in those cleaners so what do I do?

It's really not a matter of what you believe in... The solvents dissolve the varnish that plugs up the injectors - That's not even debateable. A fuel rail flush by a shop with a BG machine sounds like JUST what the doctor ordered for your J.

K&N was probably not a worthwhile purchase if you're looking for the best mileage (don't believe the hype), and the +4's are questionable too (again, don't believe the hype).

On a side note, it's interesting how many people get all excited over split or extra tips on a spark plug... Electricity takes the path of least resistance, so there's absolutely no need for the extra 3 tips. But people believe the hype.

Post by **suk my j, 30** » Mon Jun 09, 2003 5:49 am

If I was going to buy a cleaner which one do I buy?

And what about the door, it was untill a week ago?

Post by **AZhitman** » Mon Jun 09, 2003 5:49 am

BG 44K is the good stuff, or find a shop that uses the BG line of chemicals.

Post the door ? in Infiniti Online Mechanic for a better response.

Post by **Jeff Williams** » Mon Jun 09, 2003 5:49 am

I did the BG flush ($113 at the dealership, and they checked all the sensors and injectors resistance).

My flel mileage has gone up about 5% to 7%. I was getting around 20 MPG, now I have gotten (in the last 3 tanks since the flush) about 21 MPG. Not a big difference if you don't drive much, but I drive 1000 miles a week.

I also have the +4 plugs. I did not see much difference in them, except they were about $5 cheaper, each. I found a guy on eBay selling the NGK plugs. I bought a set, but am waiting another 10,000 miles, to put them on.

I have the K&N POP charger. No improvement in gas mileage, or horsepower, just sounds cooler, and requires more maintenance. You will have to clean your MAF sensor with brake cleaner about a week after you oil the filter. You are also letting in larger chunks of trash into your motor. If you drive on dusty roads, switch back to OEM, fast!

The only exhaust mod I would do would be for looks, or sound. Just about anything you do will not improve the performance, or mileage very much.

The best thing you can do to increase mileage is use the cruise control. You are gonna have to let the little rice burners blow past in traffic, if you want 22 MPG or more.

If I slow down to 65 or 70 MPH, I can get about 10% better fuel economy. I would think the opposite, if I boost my cruisint speed to 85 or 90 MPH.

Post by **Q45tech** » Mon Jun 09, 2003 5:49 am

Duh! every rpm you turn, the cylinders have to be fed with gasoline in a precise amount. Once you get above 2500 rpm the amount enrichens from 14.7>13.0> 12.0> 11.0 [at WOT] since the ecu assumes you are not interested in minimizing fuel comsumption because you are exceeding the speed limit.........70 mph at best.Acceleration is 33-45% more consumptive plus the rpm increment!

Each HP produced requires a minimum of 1/2 pound of gasoline per hour to accomplish........300Hp=150/6.3= 23.8 [+-] gallons per hour..............most 30HP [60mph] driving uses 2.38 gallons per hour~~ 25 mpg.

Post by **Jeff Williams** » Mon Jun 09, 2003 5:49 am

I've been trying to tell my wife that, for years. I tell her to let the car coast, if she is coming up to a red light, or slower traffic, it might turn green & she will not have to brake, or get on accelerator as hard. She just smiles, and runs through the brake pads, and fuel.

She used to use 2 feet, one on the brake, and one on the accelerator, when we got married. Her Cadillac never dropped below 2000 RPM's a red lights. She was always the first one to take off, when the light turned green, and that Eldorado averaged 8 MPG, and everyone at Goodyear knew her by name. I drove the car for a few weeks, to see what I could do about the gas mileage, and I got 17.5 MPG! It had that mileage computer. I used to try to get to 60 MPG every time I drove it. It had a 368, with fuel injection.

Post by **Q45tech** » Mon Jun 09, 2003 5:49 am

Now that all cars have cats and precision fuel control at cruise mileage variations are ususally just a function of rpm and engine size.

See the whinning all the time from people who up grade from a 2.0 liter to a 3.5 liter V6........two small slurps per rpm to 3 larger slurps per rpm and V8 have 4 even larger slurps.

Yet a 4.5 liter V8 can easily get good mileage [relatively] by sedate driving...........but the V8 will probably use 2 times more fuel just idling than a 2 liter I4.

I remember when I thought a 390 cu in was a small engine compared to a 454............now a 274 ci Q45 seems big compared to the vast numbers of 2.0 liter [122ci] cars on the highway.

Post by **98TURBOKA** » Mon Jun 09, 2003 5:49 am

I use to get pretty good gas mileage, probably still would if I could stay off the boost:D !

Post by **Jeff Williams** » Mon Jun 09, 2003 5:49 am

Quote »I remember when I thought a 390 cu in was a small engine compared to a 454............now a 274 ci Q45 seems big compared to the vast numbers of 2.0 liter [122ci] cars on the highway.[/quote]Yeah, my '73 442, with the 455 HO engine has monster torque, and a bunch of HP, outruns Mustangs & Camaros, but gets 10 MG around town. I can get a steady 18 MPG on the highway, though.

Nothing like the rumble of that motor, though. Scares small children.

Gas mileage?

Gas mileage?

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