Winter blend gas

New to TW, but have been lurking and learning. With a v6 4x4, I've getting 23-24 mpg, which I'm super psyched, but recently a few
mpg less. Is this due to colder temps or winter blend gas? If colder temps, why not heat the air intake and what's the point of a cold
air intake system?

 

Cold air going into the engine is more dense and has more oxygen in it. Thus there's more potential energy.

Gas mileage goes down in the winter both due to the winter gas blends and because the engine is less efficient until it gets up to full operating temperature.

 

Thanks Otter, I'm at 6,000 + and winter is winter. Does higher octane make a difference or not? I've been using 91 (highest available), but wonder if necessary...

 

Winter versus summer gas mixtures has a lot to do with volatility.

Volatility is the rate at which gasoline vaporizes at a given temperature. The volatility of a gasoline is important because the liquid gasoline must be mixed with air and vaporized in order to burn in the engine. Liquid gasoline will not burn.

The volatility characteristics of our gasolines are important to your driving performance. Gasoline with high volatility vaporizes more readily than one with low volatility. In hot weather, gasoline that is too volatile can cause vapor lock and stalling in your vehicle. In cold weather, a gasoline that is not volatile enough may cause hard starting and poor warm-up. In the winter months, for example, your vehicle's engine is extremely cold before startup, and the gasoline must have a high enough volatility to be able to vaporize easily in a cold engine environment. Our gasoline’s volatility is carefully balanced on a seasonal and geographic basis, to provide the correct vaporization characteristics to ensure proper operation in your vehicle.

http://www.exxon.com/USA-English/GFM/Products_Services/Fuels/Gasoline_FAQ.asp

 

Using a higher octane gas when your vehicle isn't tuned for it is throwing your money away.

 

The biggest contributing factor to MPG is what chris4x4 said, the cold warmup time, it uses a tonne of fuel
A few points to concider;
-tires & gear oils are stiff when cold= takes more energy to make them move= less mpg
-the AIR in the tires condences when cold=lower presures=harder to turn & effectivly a lower gear ratio also. Nitrogen is not effected by temp
-snow on the road takes more power,spinning on ice wastes fuel
-the cold air & fuel are actually a good thing, they are dencer & make the engine alot more efficient.
-You will still burn the same 14.7:1 ratio of air to fuel, so for any given amount of output power you are actually using a slightly lower volume of fuel. "very slightly"
-octane is like Rum, enough is great but more than enough isn't good.
-there are more BTU's in lower octane gasoline than in premium

(I live in northern Canada, in the winter I loose aprox 25% of my range per tank of fuel)

 

Yes, I stand corrected, however is it is very slight. If I remember correctly, the DRY effect os also a good thing inside your tire.

 

I have been averaging around 18mpg as of late, but with the last fill up and cold snap that has hit Wisconsin I am now getting about 16mpg according to the ScanGauge2.

 

There are other issues than cold-cycle enrichment and fuel blend cited above.

Transmission and differential lubricants are significantly more viscous in cold conditions. Bearing grease can freeze too. This is painfully obvious on the south end of -20 DegF but affects fuel economy to some degree at any temperature lower than the EPA test standard. (I suspect the EPA temp to be 69 DegF. Anybody know the number?) I've hard experience at -40 degrees. (F or C, it doesn't matter.) It can take many miles for crankcase oil and other lubes to warm up and flow properly, costing fuel all the time.

I've used AMSOIL synthetic lubricants since 1978. I don't make claims for MPG increases during warm conditions, although all of my vehicles, somehow, are good at beating their EPA "numbers". What I DO tell folks is that my WINTER MPG numbers don't DROP as much when using synthetics.

 

Yeah the gear lubes get really thick. We get sub -40 at times here. The gear lube is like butter when it is that cold. The operator would warm up the engine then head out on the highway. When I was a mechanic for GM I can remember overhauling rear differential's with cooked bearings that were blue from the excess heat. The crown gear would simply slice through the frozen gear lube with the result being that the pinion & axle bearings would not get any oiling. Bearings are quick to complain when not properly lubed.
Has any one else even driven on "square tires" when it's -40?

 

Yup! Courtesy of our ChAir Force (We kick butt while sitting on ours!) I enjoyed five wonderful years at Minot, North Dakota. North Dakota is also known as "Lower Mani-Skatchawan". This was after four years in Wisconsin and Minnesota. I discovered AMSOIL while living at Duluth.

Folks trying to noodle fuel economy, especially cold weather economy, should take a hint from Zen practitioners and consider the entire issue. Your square tires comment brought back memories! I still avoid nylon in the tires I buy, even though I live in "southern" Ohio. Most vinyls and foams are rigid at -20 DegF and below. Butt cookers are available on some vehicles for that reason but the rest of the truck suffers. My old FJ-40 had a pound of grease in each steering knuckle -- and manual steering. I remember needing my buddy's help to yank it around the first turn of the day on more than one occasion! Having synthetic lubes, especially the 36 pints of gear oil, made a HUGE difference in the fuel economy of that wonderful, old bucket!