mrhino

The wifes 06 crew 5.3 Went from 16.5 mpg to 11mpg overnight. Comfimed this with actual math. dividing miles driven by gallons used. I hooked up my live data scan tool and to the best of my knowledge, (which aint much) looks like everything is doing what its suppose to. I had done a TSP cam swap and their mail order tune. A month or so back and All seamed well until yesterday. The only thing thats has changed is the outside temp is now below freezing 20-22 degrees where before it had been mid thirtys. My first thought is its not goining into closed loop but scan tool says it is. Anybody have any ideas or thoughts. Thanks

FFDP

iTrader: (2)

Couldn't really tell you without seeing a log and perhaps the tune file.

I use Hp tuners so that's the only way I could help out.

Fullpower

Winter fuel.
Don't worry about it.

xr650jkallen

Same here. Winter fuel sucks. I think I'm gonna go back to locking my torque converter at a lower mph to help.

mrhino

Huh? I never made the connection. being from northern indiana all my life iv always heared of winter fuel but really never paid it no mine, Iv been driving for 30 years now and never had a occasion where i really noticed that significant drop in fuel mileage. Im not saying thats not whats going on here but i would have never though it was that much of a loss.

I did notice last weekend while driving around christmas shopping i was getting about 13.5-14 mpg and the temp was 29-31 this coming weekend its suppose to be in the 40's and will see what mpg is then

thanks for the input guys

FFDP

iTrader: (2)

I only really lose mpg because it's cold out, not because they switch to winter grade fuel. I run my engine longer to warm up and the cooler air uses more fuel. I can still get around 20ish on the open road if I want too. My around town avg drops from 12-14 to 10-11 because I use my remote start all the time.

Atomic

iTrader: (42)

Mileage drops because it takes longer to warm up, mainly.