Hi Folks,

I've noticed that my gas mileage has gone from a summer city street avg of 12.5L/100km (24mpg) to 14.5L/100km (19mpg) in temps of 25-30F. Does that seem normal to you? I use Shell 93 0ctane, 29500 'km' on a 2009 VDP.

Also it seems no one had any comments on what the typical stationary idling should be. I mentioned my prev Taurus X was almost dead quiet and a mild idle on the Jag similar to a Honda Accord. Is that normal? Only asking because I was wondering if a luxury car as the VDP would almost be silent at a stop and if there was a mechanical issue.

The air filter is new too.

Thanks for your help

 

My MPG has dropped a bit also, noticed yesterday that I was getting 25mpg vs 30+ in the summer. My car is kept in a heated/cooled garage so warm-up time is not a factor.

 

The car takes longer to warm up to operating temperature which means it runs leaner for longer? Just a guess, I may google it now to find out why it happens....

And here's a good explanation of why using the old Austin Mini metro... http://www.metrompg.com/posts/winter-mpg.htm

 

Winter blend gas carries less energy than summer blend. That alone would contribute to increased consumption, plus the longer warm up times.

 

Having the same trouble here in the UK on both my A6 and my sons X type.

Always happens at this time of year, usually see around at least 5-6mpg shaved off what we can achieve in the summer time

 

These offer some explanations ...

Why is the fuel economy of an automobile worse in the winter than in the summer?: Scientific American

http://www.foxnews.com/leisure/2012/08/03/getting-better-gas-mileage-in-warm-weather-here-why

 

Thank you for all your responses folks.

Still curious on my idling question though, any thoughts?

 

Not sure what you're asking/saying. (?)

 

Hi Mikey,

Well the best way I can describe it is like this, when you're sitting at a red light waiting, have you ever noticed how the engine is idling? Is it so smooth and quiet that you wonder if the engine is even running or does it feel like a typical midsize car or old Volvo 4 cyl idling with that slight vibration coming thru the steering column?

As I mentioned before, my Ford 2008 Taurus X was so quiet idling at a stoplight, that I wondered if the engine had stopped, it was such a smooth engine for a car it's size.

I only ask to see if their is some adjustment that needs to be done.

Thanks again

p.s. What is the reason you mentioned the regional forum?

 

My S-type has the quiet idle you describe, guess you'd need to compare with others with exactly the same car as yours though.

The Canadian regional section reference is part of my standard sig. Have a look now and then to see what's going on or post what's new in your area.

 

my 150k miles, sits quiet at idle on 500 rpm. No vibration or rumble or anything in both summer heat and winter cold.