Hey fellas, do you guys notice a rise in fuel consumption during the cold winter months? During the warmer months, I can usually get more than 300 miles before the refuel light comes on. But, it seems to be sucking up gas like water for the past month. I'm barely getting 280 miles before the light comes on. Is it because of the antifreeze additive they put in the gas mixture that's causing this? Or is there something wrong with my baby?

axleback

 

It's normal. 99 TLs have intake heater to maintain gas milage. They got rid of it since 2000 model year

Tatewaki

 

Thanks bro. That sucks. Why did they take that out? Cost or weight reduction or both?

axleback

 

I've noticed increased consumption with my '02 and when I had my mom's '00

 

Oh I so seriously doub't Honda (or any car manufacturer) would purposely get rid of something unless they made some changes in which it wasn't required anymore....especially for something that may reduce fuel efficiency/emissions.

axleback, check to see if they use oxegenated gas in your area during the winter. Thats the culprit IMO, oxygenated gas(MTBE). Oxygenated fuels have less fuel by volume and will most likely cause a drop in mileage....among other sh!t....especially on older cars.

 

Intake heater shouldn't have much, if anything, to do with mileage on a fuel-injected car, consider the manifold is dry (i.e. the fuel doesn't travel through it).

The likely source is as Tuff Gong said. Oxygenated fuels have a lower energy content, so consumption rises when using them. We don't use them here in FL, but when I was in Maine a few years ago, they were used only in the winter. I noticed a 10% drop in mileage on my '95 Accord EX, and a 15% drop on my '92 Vette, when they switched over (I calculate and track mileage on all my cars). It was an immediate change- the "summer" tank gave the usual mileage, and the first "winter" tank dropped.

MTBE is supposed to lower emissions, but there are a whole host of nasty things that go along with it (like leaching into the groundwater), including increased greenhouse emissions (which are primarily a function of fuel consumption). Dumb idea, except for the oil companies that get to sell you more fuel.

Todd

 

same reason you make more power...you are getting more air mass to your engine. Colder air is denser...remember chmistry PV=nRT? so as temperature falls, P is constant and V decreases. P is constant since we are talking about atmosphereic pressure. V decreasing means that the same volume of air contains more air. So more air into you engine means 2 things....more fuel and more power.

 

It takes longer to warm up your car in the winter.

Cheers !!!

 

I don't contest that equation and your explanation. However, I didn't experience an increase in power. I actually feel like the car reduced in power. So, it could be the oxygenated theory. Which makes sense. Since they put additives in there that don't contribute to conbustion, it could be robbing power too.

axleback

 

As a bonus,however, you can use a lower octane gas in cold weather.

 

don't push it when the engine is cold...but once it warms up, you are getting a few more ponies. We aren't talking about a ton more power, but a few ponies. Maybe not enopugh for every butt dyno to feel.......but that's for a naturally aspirated engine....if you are talking about a blown engine (turbo or supercharger)...you feel some real power! A friend with a big turbo A4 ran in August 13.3@104.5 about 75 degrees out. In October he ran a 12.9 @ 105.9 it was in the 40's on that day in October. The time is better and the trap speed is better. Trap speed is a better hp indicator.

 

That oxygenated gas is definitely one of the culprits, I have always noticed a decrease in mpg in all my cars whenver we switched over to that crapp.

Add to that idle time when its cold out or when youare clearing snow, etc off yor car, and you get worse gas mileage

 

I'm doin about 15mpg rite now. But i only drive in the city. go to skool and places.

 

Mr Hyde & drcookie are correct--one of the main reasons you use more gas in the winter is because the car simply idles longer and takes longer to get up to normal operating temperature.

Most people let their cars sit a little longer after starting to warm up (this is a good thing), and if you have a remote start you'll really see the MPG drop if you let it warm up for 10-15 minutes before you go out. Also, a cold engine will idle at a higher RPM (to avoid stalling and to get the cat up to optimum temperature faster). A higher RPM idle will consume more fuel. Likewise, cold fluids are heavier to move for the engine so that added friction causes the MPG to drop. Just like Acura switching from 5W-30 to 5W-20 for better gas mileage, the same holds true for cold vs warm oil. If you've ever poured oil out of a bottle at 0 degrees F then you'll know what I'm talking about.

Oxygenated fuels also add to this equation.

 

1)Petroleum companies do change formulation of gas for winter and that is a factor.

2)In cold weather, it takes longer for your car to get up to operating temp. When drivetrain is cold, lubricants are cold and stiff causing more resistance.

3)Cold air is more dense causing more drag on outside of car.

4)If roads are wet, more rolling resistance.

5)Car is like your body. When you're out in the cold, your body is burning energy trying to keep up at 98.6. Your car is doing the same thing - burning more fuel to keep up at operating temp. Just remember, heat is energy. In winter, you're using more gas to generate heat/energy.

 

PV/T and/or cold start operation don't explain my change in mileage. Did you not read my post? The mileage dropped 10-15% on the very first MTBE tank.

And, FWIW, I never warmed my car up for more than one minute. The above mentioned will have an effect, but if you aren't doing anything different, the majority effect is the MTBE.

Todd

 

Good call. I was wondering if someone was gunna say that or not

Yah hes right, colder weather will eat more gas because of pressure. Most times, you will not see the increase in power. The only time i did was when i had a big block 400 in a old Volvo when i was 16. Then i felt it. Alot.

 

 

You really need to look into how a closed-loop fuel control system works, because that ain't it.