MPG question

So my window stick on my 2017 TRD sport says that it gets 18-23 MPG and the website says the TRD sport get 17-21. When I first got my truck i was getting around 23-24 on average and now after 10k miles I seem to only average about 19-20 (my driving habits haven't changed). Did they mislist the MPG?

 

17-21 is manual trans. no probably fuel related. winter mix sucks. ive seen mine drop a few in the colder weather.

 

I primarily drive in town and average 17-18 MPG according to the stock fuel economy meter.

 

Winter fuel will cost your 1-2 mpg. Tires under inflated by 5 psi will cost your 1-2 mpg. As you add weight inside the truck or add on accessories it will cost you some too.

 

Winter blend and ethanol combo will suck also.

 

Yep. Winter versus summer gas. About 10% difference. Mid October to April is the winter gas. Before anyone bitches I have done a lengthy write up explaining why it happens and why we need it. I'll post it if anyone wants to read it.

 

So you are getting what it is rated to get. What am I missing?

http://www.fuelly.com/car/toyota/tacoma/2017

 

tire pressure is important......manual calls for 29psi all the way around......what do you guys have?

 

Sheet mang I’ll read it! Not gonna bitch about it but I’ve definitely noticed the difference in fuel economy on pretty much all the cars I’ve owned.

 

I was getting right around 16 in my auto dcsb with 90% city driving. I just put on some 4runner pro wheels and ko2 265 70 17c, and it went down about 2 mpg.... kinda sucks lol.

 

How are you accurately determining you MPG?

 

Trd offroad DCLB no mods 1,000 miles on it and I get 16-17. Pretty sad.

 

I put this together a few years ago for the 4Runner forum. Enjoy!
Winter" Gas Explained
Many threads have shown up in the last month or so on gas milage drop as we approach winter. Here are a few articles that explain what winter gas is and why we need it. I learned most of this stuff in college but have forgotten most of it.

One:
Here's the poop: As specified by state law, reformulated winter gas contains any number of lighter, lower-boiling-point hydrocarbons (butane, propane, etc.) that just so happen to have an excellent octane value. Added to this may be any number of oxygen-bearing ether compounds (MTBE, ETBE, ethanol) that improve emissions and also have a relatively high octane blending value.

So what's all the bad hype for? Price, for one thing "It's actually more expensive to make reformulated winter gas than normal, summer fuel, ' says Thomas Hart. Lower fuel economy is another concern.

"The oxygen-bearing compounds displace fuel components, so it takes more fuel to get the job done. Normal gasoline has a stoichiometric ratio of 14.7:1, reformulated winter fuel runs between 14.3 and 14.4:1," says Mitch Markusich.

And the complaints about poor performance? Mitch says, "When people ***** about the fuel, it's not really the fuel's fault. The weather is largely responsible; after all, it is winter. Low cranking voltage in the battery, increased oil viscosity, atmospheric condensation in underground fuel tanks and so forth."

The bottom line is that when it's cold, winter gas seems to be the hot ticket for performance enthusiasts. Not only is the dense winter air good for horsepower, but the higher oxygen content and octane value of winter gas make the pot sweeter And as for fuel economy and price? When did that ever get in the way of having a good time behind the wheel? It s just too bad we have to deal with all that snow and ice".

Two:
A Primer on Gasoline Blending
Gasoline is composed of many different hydrocarbons. Crude oil enters a refinery, and is processed through various units before being blended into gasoline. A refinery may have a fluid catalytic cracker (FCC), an alkylate unit, and a reformer, each of which produces gasoline blending components. Alkylate gasoline, for example, is valuable because it has a very high octane, and can be used to produce high-octane (and higher value) blends. Light straight run gasoline is the least processed stream. It is cheap to produce, but it has a low octane. The person specifying the gasoline blends has to mix all of the components together to meet the product specifications.

There are two very important (although not the only) specifications that need to be met for each gasoline blend. The gasoline needs to have the proper octane, and it needs to have the proper Reid vapor pressure, or RVP. While the octane of a particular grade is constant throughout the year, the RVP spec changes as cooler weather sets in.

The RVP is the vapor pressure of the gasoline blend when the temperature is 100 degrees F. Normal atmospheric pressure varies, but is usually around 14.7 lbs per square inch (psi). Atmospheric pressure is caused by the weight of the air over our heads. If a liquid has a vapor pressure of greater than local atmospheric pressure, that liquid boils. For example, when you heat a pot of water, the vapor pressure increases until it reaches atmospheric pressure. At that point, the water begins to boil.

In the summer, when temperatures can exceed 100 degrees F in many locations, it is important that the RVP of gasoline is well below 14.7. Otherwise, it can pressure up your gas tanks and gas cans, and it can boil in open containers. Gas that is boiled off ends up in the atmosphere, and contributes to air pollution. Therefore, the EPA has declared that summer gasoline blends may not exceed 7.8 psi in some locations, and 9.0 psi in others.

A typical summer gasoline blend might consist of 40% FCC gas, 25% straight run gas, 15% alkylate, 18% reformate, and 2% butane. The RVP of the gasoline blend depends on how much of each component is in the blend, and what the RVP is of each component. Butane is a relatively inexpensive ingredient in gasoline, but it has the highest vapor pressure at around 52 psi.

In a gasoline blend, each component contributes a fraction to the overall RVP. In the case of butane, if there is 10% butane in the blend, it will contribute around 5.2 psi (10% of 52 psi) to the overall blend. (In reality, it is slightly more complicated than this, because some components interact with each other which can affect the expected RVP). This means that in the summer, the butane fraction must be very low in the gasoline, or the overall RVP of the blend will be too high. That is the primary difference between winter and summer gasoline blends.

Why Prices Fall in the Fall
Winter gasoline blends are phased in as the weather gets cooler. September 15th is the date of the first increase in RVP, and in some areas the allowed RVP eventually increases to 15 psi. This has two implications for gasoline prices every fall. First, as noted, butane is a cheaper blending component than most of the other ingredients. That makes fall and winter gasoline cheaper to produce. But the increased ability to add butane also means that gasoline supplies effectively increase as the RVP requirement increases. Not only that, but this all takes place after summer driving season, when demand typically falls off. On the other hand, refiners usually draw down inventories of summer gasoline leading up to September 15th to make room for the changeover, and this can lead to vulnerabilities should hurricanes come into play (as they did this year).

These factors normally combine each year to reduce gasoline prices in the fall (even in non-election years). The RVP is stepped back down to summer levels starting in the spring, and this usually causes prices to increase. But lest you think of buying cheap winter gasoline and storing it until spring or summer, remember that it will pressure up as the weather heats up, and the contained butane will start to vaporize out of the mix.

And that's why gasoline prices generally fall back in the fall, and spring forward in the spring.

 

I noticed mine went from 20-21 down to 16-17 on this winter gas too.

 

2nd Gen window sticker for the win, no where near the real mpg.

 

I asked what people are using to gauge their MPG. I was afraid they were looking at the the "total MPG per tank" readout on on their instrument cluster. It's even more disturbing people are believing the paper work in the window. Ive always been fascinated and have wanted to ask in these threads. Again, what are you guys/gals using to tell you MPG?

 

Using accurate information is a win, I agree. Can you explain how your chosen metric is accurate, for the win?

 

I'm not worried about the metric, its the 22 mpg and 29 mpg Hwy that cracks me up. I was just pointing out that the stickers are not always (rarely) accurate.

 

Those Canadians, they use imperial gallons. 1.2 US gallons.

 

I just realized you meant the sticker is wrong, my bad. Always be worried about the metric you measure something against. It might not be accurate scaling. Or do you mean your not worried about the Metric system and that cracks you up?