Winter Fuel Efficiency????

[sunnybono]

I've noticed lately that the fuel efficiency on my 2004 Toyota Highlander with 76k kms has dropped. The vehcile is maintained more than what the manufacturer requires and I only get gas from Petro Canada.

So my question is since the weather shouldn't be a factor (mild temperatures), have the gas company's changed their formula in Unleaded Gasoline????

sk

[HighFlyer]

I filled up two days ago at PC and their pumps still had the WinterGas stickers.

[DragonZealot]

Fuel efficiency drops in the winter because it takes longer to warm up the engine and it cools down quicker.

[13inches]

Cooler, denser air requires more fuel for combustion. Combined with what DragonZealot said, you'll see a drop off in mileage over the winter.

Oddly enough, I had my best tank ever last week, but that's becuase I did 90% of my driving on the highway, with cruise, at very moderate speeds.

[baboo]

yeah, my lancer just broke the 10L/100km mark on last fill up.>:( And I don't idle warm up my car.

[mlc2000]

I usually go from 900km/tank to about 820.
diesel jetta.

[smilodon]

But as sunnybono is saying, the mild temperatures are still around and there should have been a noticeable decrease in fuel efficiency yet...

I've heard that using the "super" blends provide up to 30% better fuel efficiency than the regular blend. Although I find it hard to believe the difference would be so dramatic, it'd be interesting to know the real gain...

[Homer88]

Winter tires also makes your car eat up more gas if you have them.

[mlc2000]

^ not if you're spinning in the snow with your all-seasons. :lol:

[hytong]

what Chevron said (http://www.chevron.com/products/prodserv/fuels/bulletin/oxy-fuel/realwrld.shtml)

[abstract808]

If all other factors remain unchanged, cooler (and thus denser) air will actually increase your fuel economy, especially in diesel engines.

Unfortunately many other factors in the winter contribute to poorer fuel economy:

"Winter weather conditions can combine to lower fuel economy 20 percent, compared with the summer. In cold weather, a richer fuel-air mixture is required to start and warm up the engine. Also, much of the warmup may be done at idle (zero fuel economy) because of the need to defog or defrost windows. (During defogging/defrosting, many vehicles not only heat the air but use the air conditioner to dehumidify it.) More energy is required to overcome the resistance created by the higher viscosities of cold lubricants – engine oil, transmission fluid, and differential lubricant. Head winds increase air resistance; rain necessitates windshield wiper use; water or snow on the road increase tire-rolling resistance; and bad weather in general requires slowing to less fuel-efficient speeds."
(from http://www.chevron.com/products/prodserv/fuels/bulletin/fuel_economy/)

[new_vr]

So my question is since the weather shouldn't be a factor (mild temperatures), have the gas company's changed their formula in Unleaded Gasoline????

sk
I know winter diesel is different the summer diesel, but can't speak for gas

[squireglig]

does petro canada blend ethanol into their gas? I know pioneer and sunoco do.. maybe they've started... or like OP said, switched to "wintergas"... which is supposed to have more gas line antifreeze in it or something..

[corrupt123]

On top of what was already mentioned, I know that a lot of (if not all) gas companies actually change the gasoline somewhat from summer to winter. This has some effect on the fuel economy as well.

As for super getting better mileage... it might, it might not. If the car requires a higher octane and you're running a lesser octane on it, then you will lose fuel efficincy. Therefore, when you put in the proper (or better) gasoline, your economy will go up. I believe though if you require regular and put better gas in, it wont do anything, or much if it does do something.