xfirepwr1

I noticed that since it got colder in chicago my fuel economy got worse. I cant even get close to 300 miles on a full tank comparing to like 320-340 in the worm weather. Does worming up your car for few minutes take that much more gas?? Im not liking this at all, since the gas prices r going up again.

bert

Yeah, that sounds about right. I loose 2-3 MPG in the winter, unless I do long drives. When it's cold it must run very rich.

The faster you warm it up, the faster it should lean out. So you should (within reason) try to warm it up quickly. Should I say, you will probably burn less gas the faster you warm it up.

Stick it 2 ya

I've noticed my fuel economy start to drop too, even with a KNN air filter.

Does anyone run regular 87 octane in their 2k2? I was wondering if anyone here did since prices are kinda high for mid January.

xfirepwr1

I was thinking about switching too, I dont see why the older models have no problem with running on 87 and the new max's cant. I really dont see how this can affect the engine that much, plus like one other member said the 93 sits there for the longest time and dont you think it looses its value so it would be the same if not worse than 93

bigdo26

iTrader: (3)

far as mileage goes, i've noticed a significant drop in the past month, since its been like 20 out everytime i start my car. mileage has definatly gone down.
as for octane, i've always used the 93, and i understand we have fairly high compression engines which is why the higher octane is required, but would the 87 hurt all that much? what about 89? i should probly search, rather than post... maybe i'll do that now

nismotech

Yes, the coldness is making engine not working 100% level, so should always warm up before you start driving "normally". I always drive slow at first then return to my normal driving when I see the temp needle goes up where it should be.

87 octane? humm....I've always used 93 octane, since if you really calculate the gas you put in, the differents is like 2$ differents, at the most. and the sticker by the fuel cap says "Premium fuel recommands for Maximum performance" so I am convinced.

woreyah

Hey guys,
I'm getting 22.1 mpg which is an increase of about 1.0 during this winter. I'm using Sunoco 94 octane. Love that gas.

EJH Y2K SE

iTrader: (3)

I noticed a sharp decrease in mileage when it was extremely cold outside. We were in North Dakota over the holidays and the first half of the trip back to Nebraska we got terrible mileage. The second half we got roughly 5 mpg higher. Of course it was 2 degrees outside when we left and 38 degrees when we got home.

Does anyone know what kind of a difference putting Amoco Silver 89 octane with ethanol in it, into the car? Here in Nebraska Silver is cheaper than regular...

Virus

iTrader: (1)

Don't use anything less than 91 octane. While you may not notice a difference in performance because the knock sensor kicks in, you will eventually hurt your engine. When I get a chance I'll post links that cover this subject very detailed. Gas mileage on the east coast drops a couple miles per gallon because of the oxygenated fuel used during the winter months to cut down on pollution. You will also notice you car runs rougher.

C430

The cold-weather MPG drop is probably due to 1) engine running richer (cold air is more dense changing the ratio), and 2) oxygenated fuel, the environemtnalist's incorrect solution to pollution, you actuallyburn more fuel,nullifying the effects of the oxygenation.

As for 87 Octane, I was forced to do this once when far from home, on my '96, and I noticed the difference right away. The knock sensors work at the expense of performance. I guess if you drive it like an old lady, there's no roblem. I'm not going to risk my VQ3.5 just to save $1 per fill up.

max988

I am getting anywhere from 16.7-24.1 MPG during the winter.

itdood

MTBE (oxygenator) is added in winter, depending on local laws and such.

MTBE will cut about 5-10% off of any car's mileage (that's well documented), which is how much your mileage went down.

Warming up your car will also reduce it. It also takes longer for the car to reach stoich which will burn more. But that alone wouldn't explain the 10% hit you've taken.

MTBE also reduces HP by about 3%

MTBE is bad science, pushed into law by the rich lobbies that sell the stuff.

We should start a "Sue the MTBE manufacturers" thread for the HP and mileage hit.

Stick it 2 ya

One of my biggest gripes about the Maxima is how far off that trip computer is when it comes to calculating Miles per gallon. In the winter time I'm seeing it range from 27.0- 28.0 but I its actually 4 mpg lower than that, and thats with very easy driving. I really wish I can callibrate that thing. At least the thermometer on the Max is pretty acurate.

bigdo26

iTrader: (3)

the maxima MPG meter is definatly waaay off. i've seen this topic posted numerous times, and everyone has always said its between 3 and 5 MPGs off... mine is usually around 4, but it varies. i hate when it tells me i'm doin like 33 mpg and then i fill up and check and it only comes out to 26 or 27.. thats in the summertime though

Wasim521

iTrader: (4)

I calculated my last two tanks -

first tank - driving completely around town - 15.7 mpg
second tank - ALL highway driving - 21.7 mpg

I'm in NY. This is much lower than I got in the summer, when I got around 18-19 around town and about 25-27 mpg on highway trips. bummer.

Virus

iTrader: (1)

http://www.leeric.lsu.edu/bgbb/7/ecep/trans/b/b.htm

http://zhome.com/ZCMnL/PICS/detonation/detonation.html

http://www.misterfixit.com/deton.htm

[TYPE]SS

Simply saying, if you use anything less then 91 octane. Fuel and air mixture will ignite before being fully compressed. which is what octane ratings are all about. if you listen carefully, you would hear knocking sounds which is very bad for your engine. anywayz, i've been gettin around 16-17mpg these days on my max2kgxe. it's eating out my wallet. i live in nyc by the way. lot of stop and go, stop and go.

E55AMG2

iTrader: (4)

i barely get 300 miles to a tank in the summer, in the winter it doesnt get much worse. Maybe if i drove the speed limit, i might get better gas mileage. But hey, what's the point of making money if you cant enjoy spending it (on gas)

Virus

iTrader: (1)

Very well written!