Looking for a little help from the kind community here at T4R

I have a 2003 4runner Sport with a 4.0, used to be when I filled up my display would read approx 610kms per tankful. Currently it reads about 510 kms per tankful, I'm not even using 4wd. It seems it started doing this overnight soon after the weather got cold. Any ideas?

Also when engaged in 4wd is your VSC led supposed to be illuminated? Mine is sporadic at best

I appreciate any input

And Happy New Year all

That's all pretty normal. Winter formulation gasoline tends to get worse mpg. It takes longer for the engine to warm. When the engine is cold (below 150-170F) it burns a lot more fuel.

The slip light is only on when it's slipping...

The display would pick up on the winter formulation??

It is not the slip light that I'm talking about it is the VSC light

Thanks for your response

No, the display doesn't seem to compensate for winter fuel.

VSC light- oh, I don't know about that... It shouldn't be on unless the center diff is locked or there's a problem.

The vapor pressure specs change in winter and as such more butanes are blended into the fuel. (The primary reason is to ensure that the engine will turn over in colder weather.) With that comes a lower BTU value along with less mpg. The 4R's computer isn't that smart enough to know the formulation, but it will adjust for the amount of fuel needed to power the engine....and thus a lower range on the vehicle. The range should come back though when it starts getting warmer

I agree with Chris. The VSC light should only be on if the vehicle is slipping. If it is on continuously then you may have VSC turned off, the center may be locked (should have a secondary light)....or something is actually wrong. If the VSC light is continuously on, you could disconnect the battery for 5 minutes and let the computer reset. See if the light goes off and stays off.

^^x2^^

Another factor is air temperature. Colder air is more dense; it contains more oxygen. If more oxygen is in the air, more fuel has to be added to maintain the ideal mixture of 14.7:1.

No way around this aside from moving to a warmer climate.

Winter will definitely take a harsh stance on your fuel economy.

In 2wd and in the summer, we were getting approx 10-10.5 L/100kms.

Now in Constant 4wd and in the cold cold bitter winter here in Alberta, I'm at 13-13.5L/100kms.

Thank god the price of gas since summer is less then half!

+1

Besides the different fuel formulations in colder climates taking their toll, don't forget that your tire pressure will drop about 1 PSI for every 10 degree F temperature drop. So if you last checked your pressure at 60 degrees F and now it's 10 degrees, you've dropped about 5 PSI.