MPG, I don't believe you.

[PHeller]

People talk of 28 and 30 miles per gallon.

I don't believe them.

I've got fine looking plugs (old but clean).

I've got wires in good shape.

I've got a brand new O2 Sensor.

My car runs awesome.

I get 24 MPG driving like your grandmother in the snow...following an Amish buggy. Any amount of fun lead to 20MPG, which it seems I've been average per tank. Most miles so far was 306 miles/13.3 gallons.

Am I missing something secret that's affecting my MPG by 3-5MPGs?

[ashoe]

I am totally serious. Filled up today 12.4 gallons 357 miles. I always get within a mile or two of thirty, and i don't drive like a grandmother. The only thing i do to improve my mileage is synthetic fluids in the engine, trans and diff, and shifting into fourth or fifth anytime i'm not accellerating. I run premium in the winter because its the only gas that doesn't contain 10% ethanol around here.Check the gap on your plugs, just because they are clean doesn't mean they're working right.

[2projects2many]

OP= are you running 5-spd or autotragic? that will make a 3-5 mpg difference as well.

[PHeller]

Manual

357 miles? Jeez...

Did you do anything recently that might have helped that mileage? Plug wires? Engine rebuild? exhaust? intake?

I can't figure out where I'm losing so much efficiency.

[ashoe]

Nope. Nothing major. Mostly just trying to keep it running till i get the funds for a swap together. It seems like the dual cam engines get better mileage than the single cam engines? Mine has good compression and leakdown. Whats your wheel/tire setup? I run the stock ones most of the time because the bigger wheels i have just kill my mileage.

[PHeller]

Stock.

Stock everything.

[Vegascorbin]

Yoou may be not loosing anything. Different parts of hte country run different bleds of gasoline. A better comparison for you to make is what are others in your same reagion (useing the same blend etc.) getting for MPG?

Alot of things can make a diferance includeing altitude, humidity, fuel blend, road conditions.

The other thing to look for is a change in MPG. It can be an early sign of problems.

Just make sure that you are comparing apples to apples.

[DJ_Sunrise]

Pheller.. I feel your pain. I get about 220mpt on my S14. 15.9 gallon tank, and I usually fill up about 15 gallons. I was getting 180ish for the last few weeks. Last weekend when my car reached two hundred some odd.. I nearly crapped myself. I drive like a grandma... never more than the speed limit. It hurts.. I know.. considering I get about half the gas mileage everyone else reports. One week during the summer I paid $60 to fill up my car... I can't even remember how many times I've paid in the 50s... Ughhh.. shoot me.

-Bart

[masterdisaster]

yuuup.. sound right .. i get 30mpg on my s13 sr20det.. and pretty sure i'd do more if i did more highway.

i always take off slow but still hit a bit of boost in 2nd gear and over

[Philipio]

I actually get a lot less on the highway due to the higher RPM. When I do primarily city driving on a tank, the speed limit's 40 and I cruse in 5th gear.

I generally fill up before 12 gallons and have around 270 if I've done a lot of city driving, around 210 if primarily highway.

[rms13Mike]

i used to barely get around 275 miles for about 11-13 gallons, then i started using fuel system cleaner and it got better over time, i tried to avoid racing my engine too. and i get around 300 now. the most i got was around 350-360 i think. yeup yeup. try that or changing your fuel filter, and like what the other guy said, check your spark plug gaps

[PHeller]

Z32 Fuel filter as of a month ago. So we're good there.

Just did wires and checked the gap. They were at .045, but they were normal non-thin wire plugs, so that could have something to do with it.

Looking at picking up a set of NGK Iridiums.

[masterdisaster]

iridium :S ... that's a nono in my book .. BRK6ES and change them ever 5 months

[alfsnissan]

I get 26 mpg with my manual. Not a whole lot of city miles but some. Not a lot done to the motor, but new o2 sensors, cat, air filter, good plugs, good tires at proper inflation.

[Azrial]

I wonder what difference the air makes in CO to PA. Isn't the air thinner or something in CO.

I think i get around 20 some odd mpg my vert was an auto but now it's 5spd so it should do better. Well once I get the hang of driving it as a stick. If you haven't done a tune up recently I would go ahead and change distributor cap rotor button plugs and wires and see if it makes a difference. Every place you ever buy plugs from claim they are pre gapped generally but they are always off. Also like the one guy said different places get different gas blends. I would try going to a different station and buying gas. They all get the same blend of gas in a given area but depending on the company they all have different chemicals they add in before distributing the gas to the station.

[kainvamp]

i just filled up today and got 11.47 gallons to 333 miles. thats 29mpg. only use 93 octane. I drive pretty aggressively most of the time too, but many are highway miles.

I was getting around 25 most of the time, but after my alignment and oil change, its been consistently 27-29mpg.

its on mainly stock sr with front mount, 12psi, and 4 bar fuel pressure, z32 fuel filter, NGK bkr6's or bkr7's copper plugs gapped at .33, AFR is 12-12.5 high throttle and like 14-15 just cruisin. runs great. hopefully goin to the track tonight to see what it gets on the 1/4 mile finally.

[superficialfilter]

Have you tried checking your tire pressure? I'm not saying it will be completely responsible for your bad mileage but if their low it won't be helping it.

I just took a trip in my 97 and got 476 miles out of 15.403 gallons on the highway. Around town I've been getting 25-27mpg depending on how I drive. All I've done is put a header, intake, and electric fans on it.

[Onizuka]

Most people who report 30mpg highway have a SR swap. I got 24-26 on the ol' KA24DE and 30-31 on the SR20DET (highway that is).

[gtd65]

<--- This 95 S14 normally gets around 24mpg which I think is pretty reasonable for an older car with a cat really.

Remember, unless you are zeroing the trip meter and brimming the car (not just the first click) each time you fill up, the MPG calculation is not accurate.

[onosqv]

What A LOT of people don't realize is that their speedo is usually off. If you use a GPS w/ speedo and compare your #'s, you may see that it can be off anywhere from 5-10% at higher speeds.

[Firewind]

I got 24MPG most often when I drove light. Thing is, I am getting less MPG because I am running slightly wider tires, stock on S13 is 195/60/15R, and I have 205/60/15R that a lone can cause a change and fuel economy, let alone a difference on the speedo since my tires are slightly larger. So keep that in mind. I could most likely pull more MPG now since I have learned to have a more steady foot.

[Dimitri]

Doing only really short trips in city traffic , I get 12-14 MPG. No highway/freeway driving lately since I started keeping track.

Although I have made it from Los angeles to Las Vegas on a single full tank some years ago.

[gtd65]

At the moment I'm working over in Holland and bought myself a cheap run around in the shape of a Proton Persona (it's basically a Mitsubishi Lancer with some styling revisions built in Malaysia).



Well last year, gas was around $9 a gallon (almost $10 at the peak) so I decided to try some of this "hypermiling" stuff that I'd previously read about.

So basically in May I started the test of more conservative driving styles - can you spot the change in MPG The figures are "Imperial" MPG. US MPG is about 15% lower roughly.




Modified by gtd65 at 3:03 AM 4/29/2009

[ShaunakaRichard]

Ya the speedo is off at higher speeds but the odometer is still on. I used a GPS to compare and yes the speedo is definitely off over 55mph. But odometer was still near spot on.

[onosqv]

Ya the speedo is off at higher speeds but the odometer is still on. I used a GPS to compare and yes the speedo is definitely off over 55mph. But odometer was still near spot on.

As far as I'm concerned, the odometer is driven directly from the speedo...

You won't notice 5-10%+ differences in the odometer immediately just by looking @ it, it will equate to a good 30 miles or so off 300 miles - adds up & gives false readings.

[SullivanRacing06]

i get around 25mpg on the interstate out or a 6 cyl

[ShaunakaRichard]

Well whatever you want to believe. Taking a 180 mile trip and having the numbers differ by tenths of a mile is pretty damn close I think. And fyi, just because nissan made the face plate disproportional doesn't mean the odometer isn't correct. Odometer reads the same signal the speedo does, if theres a probelm with the speedo it won't effect the odometer. Speedo doesn't drive the odometer. Both get their signal from the sensor on the transmission.

[onosqv]

I haven't looked @ the analog cluster in a while, but the digital HUD cluster I run has the odometer running directly off the speedo unit.

Even 5% off (which is fairly standard in the 240's I've seen all over So Cal) will affect your total mpg readings. It's not as noticeable @ lower speeds because 5% equates to very small tenths, as you have said. However, it equates to 15 miles in 300 (about a tank of gas), which means the difference between reporting 25 mpg & 23.7 mpg w/ 12 gallons of gas.

This isn't THAT big of a deal, but it does affect it; also, I've noticed depending on how much highway you driver, the % off is higher. The OP is talking about 3-5 mpg difference in reporting per tank & something as simple as this is definitely a contributing factor.

[jeff420]

when i got my 240 the origional motor got 27-28 mpg driving slightly aggressive. the motor i just dropped in is getting 25mpg consistantly with no emmisions and a s***ty transmission thats going to lock up on me any day. with the first engine i had a different j30 rear end than im running now. i dont know if j30's came with different gear ratios.

[SRprelude]

yea, Im 22-25 mpg depending how i drive my SR20..... and thats as good or better than my KA was