Dang Winter fuel

[RedOak]

Checked my mileage on a recent fill and it was down to 28 mpg on my 01 Sunfire with the old 2.2 ohv. I have been using MMO at 3 oz per 10 gallons of gas. This tank was with interstate driving and to and from work here in Michigan. Summer mileage was around 33 mpg. I am sure ethanol is no help either.
The higher volatility of winter fuel or RVP in comparison to summer gas is around 3 percent from what I have read. Higher gas prices and less and less mileage. Thanks EPA.

 

[nitehawk55]

Winter fuel is part of your lower milage but cold starts and warm up time will effect it too .

 

[SLCraig]

I also hate winter gas. As soon as November/December comes around my mileage goes right down the tubes. By about 100KM per tank. Not fair!

 

[RedOak]

The mileage drop was using Shell gasoline. I usually run Murphy's gas which come out of a refinery in Wisconsin and is sold and stations in Walmart parking lot's.

 

[lexus114]

I lost an average of 2 MPG`s EPA sucks!!

 

[JDD]

Originally Posted By: lexus114
I lost an average of 2 MPG`s EPA sucks!!


+1 I lose about 1 to 2 MPG with winter gas. It's worse with my older vehicles (1996 and 1998). I lose 2 with those and 1 MPG with my 2005 and 2010 cars.

 

[Errtt]

Winter formulation sucks - sucks more gas. I notice it the most on the motorcycles.
Ethanol - less is better

 

[hardcore302]

ugh, i bought my saturn with the v6 because i wanted a little passing power. now i realize it gets worse mileage than my GT!!

and now with this winter gas, it's almost as if i can watch the dial go down while i drive both cars! [censored]

 

[Eddie]

The fuel is reformulated so your vehicle starts and runs better in the winter. I won't whine and complain about that.

 

[fdcg27]

Good point.
How much of the loss in fuel economy is caused by the engine spending more time in open loop, with oil thickened by the cold, and how much is caused by the more volatile winter fuel?
Also, could reliable starts on really cold mornings be realized with lower RVP summer fuel?
I don't really like the 10% loss in fuel economy I typically see over the cold months.
OTOH, I do like the fact that I can count on everything starting on a It would be interesting were someone to take a vehicle on stockpiled summer fuel, and let it cold soak overnight on a really cold night, just to see whether and how easily it would start.
My guess is that it probably wouldn't matter until ambient temps got somewhere below -10F.

 

[SteveSRT8]

I can tell you that at 17 degrees F startup my truck goes into closed loop in less than 60 seconds. Unlikely to do much for mileage, good or bad.

Like you said, in wicked extreme cold the fuel could be a real issue. But my personal opinion is it's the blend they give us.

 

[InvalidUserID]

My 99 Civic dropped from 32-33 mpg in the summer/fall to 30-29 in the past two months or so with the same driving route and driving tendencies.

I don't know how much temperatures have contributed (coldest in the Bay when I leave is maybe 40 degrees) so I'm guessing its more of the fuel winter formula.

 

[Eddie]

Not just engine oil but, all lubracating fluids & oil.

 

[severach]

Originally Posted By: fdcg27
How much of the loss in fuel economy is caused by the engine spending more time in open loop, with oil thickened by the cold, and how much is caused by the more volatile winter fuel?

In the Northern Hemisphere we can test that every April and May where we have winter fuel and summer temperatures.

 

[countryboy9799]

On our three cars we get an average of about 28 to 31 mpg. They are all at 23 to 25 now so that really sux bad. On our Buick we have a scangauge 2 and its interesting to see how bad mileage is for the first 10 miles. With below 0 temps the transmission doesn't shift into overdrive for 4 miles till its warmed up and that doesn't help. We are not idling to much either.

 

[flatlandtacoma]

Winter fuel has a small effect but the longer warm up times and time spent operating with zero degree coolant and oil is the big factor as countryboy and others have mentioned.