^^^
No. Actually you should do that, but it does factor into total average mpg. I have always let my car warm up. My basic rule of thumb is not to let the oil pressure get over 90psi in the morning and let it idle for about 5 min. or more before driving. I actually use the oil pressure guage as my tach.

 

I would agree that its the colder temps. You burn a lot more fuel at startup when the vehicle is in sub zero temps (remember pulling out the choke in the old days).

 

Winter blend gas is the biggest problem, relating to overall mpg. I saw, at least, a 75 mile decrease in total miles for a full tank. That, and idling (or warming up) the car in the cold mornings burns gas without any mileage.

 

I thought it may be the weather! Glad you guys confirmed...

The car definitely doesn't like to start on cold mornings - my garage isn't heated. But hey, at least I have a garage, I suppose.

Still doing the preventive maintenance though as necessary... Thanks again guys.

 

+1 I have been noticing that this past month. I have been going through my tank a lot more faster than ususal.

 

Man Im lucky to get 17mph....I usually average somewhere around 15-16mpg. Damn my lead foot.

 

Ethenol blend reduces MPG. That happens to all my cars, not just the Z. Plus a little of what everyone else mentioned.

 

14.3 on the streets. Damn you boost and 275 Tires Oh and warm up time kinda kills it to.

 

as i said before, its the weather, my over all mpg per fill-up has tanked about 06 - 70 miles less.

 

I didn't notice a change in mpg with my Z when the temps dropped here in Western, NY but i took my Z off the road in November (wishes he was from PA, atleast they don't use materials on the road that lead to rust ie:salt).

 

It may also be due to the fact you are using the heater more due to the cold- this would decrease your mileage.

 

I thought the mix was richened when the temperatures get hot to help prevent detonation, not the other way around.

 

I'm pretty sure our roads get salted also, so no big advantage to moving here. Plus our roads are $hit...

 

On a side note, The digital gauge is actually pretty good (to my surprise). I calculated my MPG manually and it was within .1 of what the gauge said.

The speedometer on the other hand isn't as accurate. At low speeds like below 50 its almost dead on. Between 70-90 mph it reads between 2-3 mph high. Over 100 it's more than 4-5 mph high, and increases as you go faster. (All assuming that the GPS speedometer in my head unit is accurate)

 

I was getting bad fuel economy...turns out my pop-charger was filfthy...I cleaned it and oiled it up, now MPGs are back to normal.