Gas mileage... Manual shifting a automatic

I purchased my 2017 Tacoma OR in September. At first the gas mileage was around 21mpg till about 3 weeks ago. In the past 3 weeks the temperature has dropped and we now have snow. I noticed my gas mileage plummet to between 12-14 mpg, that's a huge loss from 21 mpg.
So I decided to manual shift my automatic. At first I was averaging about 16 mpg but I knew I could do better. After several times of messing around with different rpm shifts I decided to just listen to the transmission. While doing this I am now averaging 20mpg ( thank god). I don't think I could afford the 12-14 mpg throughout the rest of this winter.
Has anyone else experimented with this ? If so, what were your results?

 

Do you have winter blend gas in your area? That ethanol crap lowers my mileage!

 

Unfortunately yes but not all stations carry it.

 

That is a crazy drop.

I had no idea the winter blends sucked that bad.

I've been watching my mileage and it's not varied much at all since the temps have dropped off into the recent lows of high 30's. I realize this isn't that cold compared to what many on TW are dealing with, though.

 

Winter gas definitely affects MPG. I track mine and in the 5 years I've had my second gen, the economy drops from around 19 to around 16 starting in mid-October and comes back up in March-ish. However, winter gas alone isn't accountable for the entire drop you're seeing. There are many other reasons why cold weather lowers fuel economy. Take a look at this:

https://www.fueleconomy.gov/feg/coldweather.shtml

 

I manually shift most of the time so I wouldnt be able to tell a difference.

 

Thanks for the article. Like they say ... You learn something everyday.

 

Out of curiosity how are you shifting it?
I am experiencing the same thing. Went from average of 21.5(50/50 driving) to 16.0 with the same driving.
I am kind of interested in trying this.

 

How much air have your tires lost? Temps drop, tires pressures do too.

 

Mine are only down about 2 pounds

 

I hardly notice a difference between summer/winter blend gas on long trips. Repeated short trips in cold weather is what kills my fuel economy the most.

 

I've noticed recently my MPGs have dropped from 18-20 average to 14-15.......And this is here in Georgia with mainly city driving......Granted the temps have dropped from the 50s to the low 30s. I know that it isn't as extreme being down south but it definitely caught me off guard.

 

dropped from 14 to 13 average. Then again I drive in city traffic up larger hills both ways every day...
As far as manually shifting I think you may be doing more harm than good to your mileage. S mode only sets the highest gear the transmission can shift into, so if its up shifting when you bump it up you're going too late and keeping the revs higher for longer. There must be some other outlier for your 12 mpg. Just filled up and that was your mileage from the station to home but not your long term average?

 

Winter gas sucks, add to that, running rich longer and warm ups, plus .23 cents added state tax. Drove home in 4x4 @ 40 to 50 mph in snow last night and got 21.2 mpg on that 57 mile trip, not bad for 4x4.

 

I have never checked mileage on anything. Cars or trucks. Fill up with 91 etoh in my area. I suppose if you check it once in a while like oil level you might get a sense of an impending problem. Bruce

 

The best way to save is if you can find 100% gas, no ethanol or additives.

 

What rpm do you shift at?

 

I don't shift at a certain RPM. I shift by listening to the transmission. What I mean is....You can sense when it needs to be shifted.

 

Interesting........, seat of the pants.
I can identify with that.

 

I always use the sport shift as most times we drive in 4rth or 5th gear. In regular drive, you can controll shift points by pressing the go pedal more agressably but that eats more gas.