ofc319

It's finally turned to winter here in Eastern Pa. Just wondering if anyone else has experienced a major drop in gas mileage with the colder weather?

I have burned through a half tank with only 106 miles to show for it. Normal driving, even a bit more cautious after the recent storm.

I know the formulation changes in the winter, but this is pathetic. I am wondering if perhaps my computer is out of whack? My first step will be to fill it again and see what happens, but I only drive 10 miles a day, so I thought I would get a jump on the situation and see if anyone else is having any trouble?

On a side note, the snow is pretty, but it sure makes my car look ugly.

Thanks.

DEVO

I don't know the exact science behind this but I do know that the fuel you get at most gas station is different during the winter months. I don't know which chemical they add but it affects gas mileage but helps your car during the winter.

Kept that in mind... plus if you let your car warm up before you drive, you are burning fuel that will go against your mpg.

larchmont

Yes -- I've been noticing that too, for maybe the past month. Didn't know what was going on.

DEVO

Here is a link...

don't when it was written... I know of many states that have a ban on MTBE. Also, I can't find in the article how winter gas actually hurts your gas mileage... if anything your performance goes up.

the truth about winter gas

majormojo

I've always figured that most of the decrease in fuel economy in the winter is due to things like longer warmup times, slower driving with more stops, wheelspin on slippery surfaces, etc. Generally a lot more time spent sitting still and idling than in summer. I doubt that different gas formulations in winter would have much effect.

ofc319

Thanks to everyone for your thoughts. I am heading out tonight to fill up the tank, unless something miraculous happens, my mileage is going to be well under 20mpg.

Even on the highway last night I could watch the gauge move on a 20 mile trip.

Next stop is a quick call to the dealer, maybe they have an idea?

I will let you know what my mpg is for those interested.

Roadrunner_RENAMED

Just FYI, we have had some cold here in North Fl, High 30's at
night and low 50's day and my fuel usage has not changed
at any significant rate.
I do not think we get winter gas here so that may be the culprit.

DEVO

FL doesn't get winter gas.

bob shiftright

According to the EPA on RFG (Reformulated Gasoline): "Winter RFGs contain approximately 3.0% less energy per gallon than winter conventional gasolines." So I don't think most people would notice much unless they are anal enough to log in and calculate gas mileage for every tankful. Then again, we have one car with 180k on it and have logged in every single tankful since the car was delivered. Maybe we're not alone?

From the EPA on RFG

larchmont

You don't have to be anal. In fact, if you have Nav, you don't have to be anything. (Does your car have Nav, Bob? Your sig doesn't say. I would guess you don't, because of how you put this.)

On the Nav, the Trip Computer shows you how much MPG you've been averaging. The way most of us use it, it starts from scratch with every fill-up, so whenever you hit up the Trip Computer, you see how you've been doing lately. A 3% difference is (in rough terms) about 1 MPG (actually slightly less, but that's about the order of magnitude), which is enough to be noticed.

bob shiftright

No, I don't have the nav ... just because I figured that after 150,000 miles a dead black screen in the middle of the dashboard would be a resale killer, not a resale feature. I do have a trip computer on my Volvo which doesn't seem particularly accurate tank-to-tank although the MPG has been hanging around the same number for the last 100,000 miles. Not that I miss it, I usually have the Volvo computer dialed to the outside temperature, which the Acura gives you anyway. That trip computer certainly is an easier way to find out without all the anal bookkeeping. I'd still log it because I like to total up all the $ numbers when I finally get rid of a car, which is usually a shocker and explains to me why I don't have Bill Gates' or Warren Buffet's fortune, it's because I'm pissing all my money away on stupid cars.

If you read through the EPA statement it's amazing that the brand-to-brand, summer-winter and RFG-non RFG variability in fuel energy content is so high. Ethanol of course is pretty low in the BTU/volume equation, diesel fuel would be highest. They "should" sell fuels by the BTU, not by the gallon or liter to be most accurate.... or at least tell you the BTU content with a label on the pump. I live in a RFG area but try to fill up in non-RFG areas when I can. So I guess I've been aware of this for years.

DEVO

no need to be anal... your car will tell you. my hybrid shows my average dropped about 5mpg in the winter so far.

actually the combination of going with a heavier tire (winter tire) didn't help either.

ofc319

Call me anal. I love to know how many MPG I am getting in any car. Maybe it is a guy thing, or an inherited gene, my father loves it too. Something to do I guess.

In any case, my last tank was just a tad over 17MPG, whereas a week before, I was at 24/25.

I called Acura, who says it is just the change in the gas, that I should expect a 4-5 MPG drop with the reformulated gas. I'm not a scientist, but that seems like a large decrease, too large. If it continues, I will drop it off to make sure everything is ok.

So, I am now thinking maybe it also has to do with the brand? That worst tank was Exxon. So far, on a fill with Sunoco I am on track to do at least 20MPG.

I've tried to be extra concious of how I drive the car, but winter or not, it is hard not to put your foot in it when you have such a great car.

SilverTSXinPA

RFG is one of the biggest scams ever perpetrated on the American public. The gas is more heavily oxygenated to "decrease harmful emissions." In reality...it is pick up by the oxygen sensors as more air...and in turn pups more fuel into the gas. This same increase in oxygenation is also found in winter fuel mixes. So..you pump more fuel and get reduced mileage. The the person above from Jacksonville, FL...used to live there. The gound temperatures where the tanks are stored do not get as cold as in the north and you most likely do not get a winter mix of fuel.

ABP-CL9-TSX

Here where I live they use the reformulated gasoline, but gasoline is still relatively cheap and I don't notice whether this RPG is good or bad since I've been using it for sometime on my other cars with no problems.

I am averaging around 19-22MPG in the winter in my TSX. The best mileage I got in the TSX was 32MPG back in September. The cold weather is harsh on the car and the gas mileage.

aj-tsx

For what it's worth I've noticed a small drop in MPG between using AUTO (22.5 mpg) vs. manual (and turning the A/C off - 24.5 mpg) to heat the car. You can hear something engage when you turn on the climate control (either way) and then dis-engage when you turn the A/C off. It was only one test, so it's not scientific.

rx3604

I'm on Long Island, NY where it has been in the 20s for almost 2 weeks now. I have not seen a drop in gas milage. I've been averaging about 24-25 mpg. City and Highway combined. I would have the dealer check this out and also check your tire pressure. That could throw off the gas milage too.