When temp drops so does MPG ????

[bzizzi]

Took the family shopping at King of Prussia in phili.on saturday,drove all highway miled @70mph and only got 17mpg
with an 05 4R W/V6.I usually shop there twice a year and in the summer got 22mpg.What gives ????

 

[toto]

Two things change in the winter - the air is colder, and in the northern parts of the U.S. we have "winter gas", which is a slightly different blend that starts easier in cold weather. So yes, these factors make MPG go down.

Here's a recent thread on the subject.
http://www.toyota-4runner.org/showthread.php?s=&threadid=32405

The cold air also lowers the air pressure in your tires, so also make sure those are where they should be. Check them after your truck has been outside in a parking lot for a couple of hours.

 

[nated05]

I have noticed the opposite here in the midwest. My mpg increases very slightly during the winter I would assume from not running the AC compressor the entire time.

 

[Jaebster]

On the other hand, doesn't cooler (or cold) gas give you better engine efficency translating to better fuel economy?

 

[SConnors]

Any improved combustion efficiency from the colder,denser air is ofset by pushing the wehicle through that same colder denser air...

 

[TRBenj]

On the other hand, doesn't cooler (or cold) gas give you better engine efficency translating to better fuel economy?

Nope. When air is colder, it is more dense. More oxygen = more fuel. This results in better performance (more power) but decreased MPG. You'll notice the opposite happens if you drive at higher altitudes where air is thinner (increased mileage, decreased power).

 

[Jeep to Yota]

I was about to post on a similar topic, but thought I would tag onto this one. I just recently switched to Revo's from Duncrap's but stayed with the stock size. I feel like as my speed goes up my gas gauge goes in the opposite direction. Seriously, I am probably down to getting 14-15mpg (Sport V8) compared to 17-18 normally. I thought it was due to the tires and maybe tire pressure, but it sounds like could be winter gas.

What is everyone running their Revo's at in terms of PSI (I will also search)?

 

[bzizzi]

I did check the tire pressure before the trip and filled each to 34 psi
I am running Revo's,I forgot the spare and the low tire warning light came on on the way back and I filled it the very next day.It was actually at 22 psi when I checked it.The outside temp was thirty degrees.

 

[Casper]

density altitude is a *****