Anyone notice this?

When temps are above 45F I get around 390 miles to the tank, ~23MPG.

When temps are between 30F and 45F I get around 340 miles to the tank, ~20MPG.

When temps are below 30F I get about 305 miles to the tank, ~18MPG

I know there are additives they put in the gas for the winter
but can it be the car just burns more gas when it gets real cold out ?

RJP

You're right on both accounts. Two things have major impact on your MPGs (assuming you don't hot rod it everywhere):

1) Cold weather (sub 60 degree temps) starts. A cold engine takes a lot of fuel to reach operating temp. The air/fuel mixture is very rich so that the motor warms up quickly. Many late model cars get 5-10mpg during the 5 minutes or so it takes to get to operating temp. If you do a lot of short trips (below 10 miles), your MPG could be downright dismal. An engine operates at peak efficency when the heads and block are hot and the intake manifold is cold (dense intake charge).

2) "Winter" gas. For those of us that live in states where the temps go below 60 degrees for long periods of time, we are blessed with getting winter gas. This gas is highly oxygenated and has many additives to reduce the cold start emissions. There are numerous problems with these fuels. Oxygenated fuels are more volatile therefore they evaporate quicker. Oxygenated fuels have less available energy. It's not uncommon to see a 10% drop in MPG simply be switching to winter gas. This year a new required winter gas blend went into effect and people's MPGs dropped significantly (+15%).

I've only had my 03 sedan (23K miles) for a month and I don't drive it hard at all, but I'm only getting about 18mpg in 70% city / 30% highway driving. Temps have been in the 20s to 40s here in Kansas City. My wife's Subaru Legacy GT wagon auto is only getting 19mpg when in the warmer months it usually gets 23mpg. My old Maxima went from averaging 23mpg down to 19mpg once the winter gas came into effect in November.

Just another good reason for me to permantly move down south.

You are getting very good gas mileage! I rarely get more than 300 miles out of a tank of
gas here in the Houston area. Of course when I drive the highway, I get more. What mixture of city/highway miles are you referring to?

I wished I get 20mpg's like you guys do. I've had my car since Christmas. Has about 1100+ miles on it. My avg miles per gallon is 16 and that's from city and highway. Also, I don't even rev high because it's still within break-in period.

I do 80% Highway 20% city.

Heh heh......my whopping 16 mpg is, unfortunately, totally proportionate to the frequent over application of right foot pressure. I was ecstatic when I got it up to 16! No sh*t and here I am...LOL And just think....I used to pee and moan about my S. Chrgd. Chevy Avalanche getting only 16 mpg.....and that was 365hp+...HOOHA...jbx

When I drive the highway, my speed is usually around 80 - 90 mph. When
I drive like that, my mpg is about the same as city, 18-20 mpg. If you
drive highway at speed limits, you will get 20-25 mpg. But this car demands
to be driven at 80-100. God, I love to take her up to 110!

Most of the time I keep it at 80MPH on the Hwy and still get the 23MPG
in the warmer weather. I have my moments but I don't drive the whole way at 90-100. Maybe I'm getting old.

I live in the S. Cal area. So its always pretty warm. I have an 03 6mt sedan And I aways get between 400 and 460 Miles per tank. About 90% of my driving is highway but even with 130+mph runs for 5-10 minutes I still get pretty good mileage out of my G. However most of the time I shift at 2k RPM also.

Not to mention the fact that in hot weather you may well be running your A/C which likely contributes more to the gas-milage difference than either of the factors you mention.

Yeah no Sh-t...Infiniti states 27 hwy....HAHAHA my car doesnt even breathe hard at 80-100, which is what I usually do on the hwy. These cars are too nice and smooth to do 65. At that speed, Im pulling my hair out and contemplating driving in the emergency lane.....

BTW what is your rpm's at 80mph? Mine is 3k....anyone else?

WOW!!!!!!! Imagine 460 out of 1 tank. I'll never see it.

Hahaha yeah I know... must have that first hybrid...You know, 3.5 liter and 45 steroid laden pissed off hamsters in the trunk...

The term "tank" shouldn't even be used because it's a loose term. Is that 460 miles till the low fuel light comes on (16-17 gallons used, 27mpg) or is the car running on fumes (19+ gallons used, 24mpg). Everyone really needs to be using MPG, not per tank. Also, people need to note how much of that is city and highway. It makes a huge difference because accelerating a car from a stop sucks out a lot more gas than a steady cruise on the highway.