[cptJLPicard]

The other day one of my friends asked me if now, with warmer weather, I see any change in fuel consumption. His ride is a 2008 Cadillac CTS 3.6 - mine 135i. My answer: no change for me, never had, summer/winter I get and avg of 9.4, mixed hwy and city. He does get a better millage now, with spring here.

So, what is your experience? And, if you do see a diff, what would you say is the reason (assuming a consistent way of driving... )?

[bambooi]

I never pay close enough attention.

[paradoxical3]

Technically I get better mpg from summer gas.

But once I get summer tires on I spend more time with the pedal to the floor than not, so my mpg goes way down.

[631twentyeighteye]

With my old diesel i noticed a huge difference since they would put anti gelling chemicals in. usually about 5mpg(down from 25-20). With my bimmer, i notice zero different. 23-25mpg 80% highway always using the same mobil 93 octane.

[cptJLPicard]

Originally Posted by paradoxical3

Technically I get better mpg from summer gas.

But once I get summer tires on I spend more time with the pedal to the floor than not, so my mpg goes way down.

LOL +1

[cptJLPicard]

Originally Posted by 631twentyeighteye

With my old diesel i noticed a huge difference since they would put anti gelling chemicals in. usually about 5mpg(down from 25-20). With my bimmer, i notice zero different. 23-25mpg 80% highway always using the same mobil 93 octane.

My wife drives a 2005 vw golf diesel (guess what car is sitting on the driveway ) - zero difference

[631twentyeighteye]

I mean a old school(and my own personal favorite) common rail diesel, not the TDI's. It was a 2.8 4 cyl turbo diesel from vm motori in a 06 liberty. Most reliable car my family has ever owned.

[BillionPa]

2 things happen during winter

1: air is colder, so interooler is much more effective, meaning engine can use more timing advance and get more power from the same amount of a given octane fuel

2: air is colder, so engine takes longer to warm up, using more fuel

additionally for me:

3: winter tires go on, they are thinner, better gas mileage
4: winter tires go on, they have more rolling resistance, better gas mileage cancelled out
5: winter conditions mean driving slower about 15% of the time, gas mileage goes way up, but can go down if the snow is deep enough

since i drive longer distances, 2 is inconsequential, and 1 helps, and 5 generally improves trip econ by 20%

my N54 mileage this winter was identical to that during the summer

[shivaswrath]

3 mpg...

[beamer116]

During the winter it burns more fuel for me. Depending of course on the definition of winter and summer.

[tpg22]

I track every mile and gallon used on fuelly.com. In my Jetta TDI wagon I average about 4-5 mpg less in the winter months. Once it gets back above 40 degrees I start to see 40mpg again. Never in the winter. I usually get 36-37 mpg during the winter months. This is in tracking 35000 miles.